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2014-11-14mm: memcontrol: do not iterate uninitialized memcgsJohannes Weiner1-4/+31
commit 2f7dd7a4100ad4affcb141605bef178ab98ccb18 upstream. The cgroup iterators yield css objects that have not yet gone through css_online(), but they are not complete memcgs at this point and so the memcg iterators should not return them. Commit d8ad30559715 ("mm/memcg: iteration skip memcgs not yet fully initialized") set out to implement exactly this, but it uses CSS_ONLINE, a cgroup-internal flag that does not meet the ordering requirements for memcg, and so the iterator may skip over initialized groups, or return partially initialized memcgs. The cgroup core can not reasonably provide a clear answer on whether the object around the css has been fully initialized, as that depends on controller-specific locking and lifetime rules. Thus, introduce a memcg-specific flag that is set after the memcg has been initialized in css_online(), and read before mem_cgroup_iter() callers access the memcg members. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-07memcg: oom_notify use-after-free fixMichal Hocko1-0/+4
commit 2bcf2e92c3918ce62ab4e934256e47e9a16d19c3 upstream. Paul Furtado has reported the following GPF: general protection fault: 0000 [#1] SMP Modules linked in: ipv6 dm_mod xen_netfront coretemp hwmon x86_pkg_temp_thermal crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ablk_helper cryptd lrw gf128mul glue_helper aes_x86_64 microcode pcspkr ext4 jbd2 mbcache raid0 xen_blkfront CPU: 3 PID: 3062 Comm: java Not tainted 3.16.0-rc5 #1 task: ffff8801cfe8f170 ti: ffff8801d2ec4000 task.ti: ffff8801d2ec4000 RIP: e030:mem_cgroup_oom_synchronize+0x140/0x240 RSP: e02b:ffff8801d2ec7d48 EFLAGS: 00010283 RAX: 0000000000000001 RBX: ffff88009d633800 RCX: 000000000000000e RDX: fffffffffffffffe RSI: ffff88009d630200 RDI: ffff88009d630200 RBP: ffff8801d2ec7da8 R08: 0000000000000012 R09: 00000000fffffffe R10: 0000000000000000 R11: 0000000000000000 R12: ffff88009d633800 R13: ffff8801d2ec7d48 R14: dead000000100100 R15: ffff88009d633a30 FS: 00007f1748bb4700(0000) GS:ffff8801def80000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f4110300308 CR3: 00000000c05f7000 CR4: 0000000000002660 Call Trace: pagefault_out_of_memory+0x18/0x90 mm_fault_error+0xa9/0x1a0 __do_page_fault+0x478/0x4c0 do_page_fault+0x2c/0x40 page_fault+0x28/0x30 Code: 44 00 00 48 89 df e8 40 ca ff ff 48 85 c0 49 89 c4 74 35 4c 8b b0 30 02 00 00 4c 8d b8 30 02 00 00 4d 39 fe 74 1b 0f 1f 44 00 00 <49> 8b 7e 10 be 01 00 00 00 e8 42 d2 04 00 4d 8b 36 4d 39 fe 75 RIP mem_cgroup_oom_synchronize+0x140/0x240 Commit fb2a6fc56be6 ("mm: memcg: rework and document OOM waiting and wakeup") has moved mem_cgroup_oom_notify outside of memcg_oom_lock assuming it is protected by the hierarchical OOM-lock. Although this is true for the notification part the protection doesn't cover unregistration of event which can happen in parallel now so mem_cgroup_oom_notify can see already unlinked and/or freed mem_cgroup_eventfd_list. Fix this by using memcg_oom_lock also in mem_cgroup_oom_notify. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=80881 Fixes: fb2a6fc56be6 (mm: memcg: rework and document OOM waiting and wakeup) Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Paul Furtado <paulfurtado91@gmail.com> Tested-by: Paul Furtado <paulfurtado91@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-04memcg: reparent charges of children before processing parentFilipe Brandenburger1-1/+9
Sometimes the cleanup after memcg hierarchy testing gets stuck in mem_cgroup_reparent_charges(), unable to bring non-kmem usage down to 0. There may turn out to be several causes, but a major cause is this: the workitem to offline parent can get run before workitem to offline child; parent's mem_cgroup_reparent_charges() circles around waiting for the child's pages to be reparented to its lrus, but it's holding cgroup_mutex which prevents the child from reaching its mem_cgroup_reparent_charges(). Further testing showed that an ordered workqueue for cgroup_destroy_wq is not always good enough: percpu_ref_kill_and_confirm's call_rcu_sched stage on the way can mess up the order before reaching the workqueue. Instead, when offlining a memcg, call mem_cgroup_reparent_charges() on all its children (and grandchildren, in the correct order) to have their charges reparented first. Fixes: e5fca243abae ("cgroup: use a dedicated workqueue for cgroup destruction") Signed-off-by: Filipe Brandenburger <filbranden@google.com> Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [v3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04memcg: fix endless loop in __mem_cgroup_iter_next()Hugh Dickins1-2/+2
Commit 0eef615665ed ("memcg: fix css reference leak and endless loop in mem_cgroup_iter") got the interaction with the commit a few before it d8ad30559715 ("mm/memcg: iteration skip memcgs not yet fully initialized") slightly wrong, and we didn't notice at the time. It's elusive, and harder to get than the original, but for a couple of days before rc1, I several times saw a endless loop similar to that supposedly being fixed. This time it was a tighter loop in __mem_cgroup_iter_next(): because we can get here when our root has already been offlined, and the ordering of conditions was such that we then just cycled around forever. Fixes: 0eef615665ed ("memcg: fix css reference leak and endless loop in mem_cgroup_iter"). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-25memcg: change oom_info_lock to mutexMichal Hocko1-3/+3
Kirill has reported the following: Task in /test killed as a result of limit of /test memory: usage 10240kB, limit 10240kB, failcnt 51 memory+swap: usage 10240kB, limit 10240kB, failcnt 0 kmem: usage 0kB, limit 18014398509481983kB, failcnt 0 Memory cgroup stats for /test: BUG: sleeping function called from invalid context at kernel/cpu.c:68 in_atomic(): 1, irqs_disabled(): 0, pid: 66, name: memcg_test 2 locks held by memcg_test/66: #0: (memcg_oom_lock#2){+.+...}, at: [<ffffffff81131014>] pagefault_out_of_memory+0x14/0x90 #1: (oom_info_lock){+.+...}, at: [<ffffffff81197b2a>] mem_cgroup_print_oom_info+0x2a/0x390 CPU: 2 PID: 66 Comm: memcg_test Not tainted 3.14.0-rc1-dirty #745 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS Bochs 01/01/2011 Call Trace: __might_sleep+0x16a/0x210 get_online_cpus+0x1c/0x60 mem_cgroup_read_stat+0x27/0xb0 mem_cgroup_print_oom_info+0x260/0x390 dump_header+0x88/0x251 ? trace_hardirqs_on+0xd/0x10 oom_kill_process+0x258/0x3d0 mem_cgroup_oom_synchronize+0x656/0x6c0 ? mem_cgroup_charge_common+0xd0/0xd0 pagefault_out_of_memory+0x14/0x90 mm_fault_error+0x91/0x189 __do_page_fault+0x48e/0x580 do_page_fault+0xe/0x10 page_fault+0x22/0x30 which complains that mem_cgroup_read_stat cannot be called from an atomic context but mem_cgroup_print_oom_info takes a spinlock. Change oom_info_lock to a mutex. This was introduced by 947b3dd1a84b ("memcg, oom: lock mem_cgroup_print_oom_info"). Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-30memcg: fix mutex not unlocked on memcg_create_kmem_cache fail pathVladimir Davydov1-4/+3
Commit 842e2873697e ("memcg: get rid of kmem_cache_dup()") introduced a mutex for memcg_create_kmem_cache() to protect the tmp_name buffer that holds the memcg name. It failed to unlock the mutex if this buffer could not be allocated. This patch fixes the issue by appropriately unlocking the mutex if the allocation fails. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Glauber Costa <glommer@parallels.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: remove unused code from kmem_cache_destroy_work_funcVladimir Davydov1-4/+2
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: fix css reference leak and endless loop in mem_cgroup_iterMichal Hocko1-5/+13
Commit 19f39402864e ("memcg: simplify mem_cgroup_iter") has reorganized mem_cgroup_iter code in order to simplify it. A part of that change was dropping an optimization which didn't call css_tryget on the root of the walked tree. The patch however didn't change the css_put part in mem_cgroup_iter which excludes root. This wasn't an issue at the time because __mem_cgroup_iter_next bailed out for root early without taking a reference as cgroup iterators (css_next_descendant_pre) didn't visit root themselves. Nevertheless cgroup iterators have been reworked to visit root by commit bd8815a6d802 ("cgroup: make css_for_each_descendant() and friends include the origin css in the iteration") when the root bypass have been dropped in __mem_cgroup_iter_next. This means that css_put is not called for root and so css along with mem_cgroup and other cgroup internal object tied by css lifetime are never freed. Fix the issue by reintroducing root check in __mem_cgroup_iter_next and do not take css reference for it. This reference counting magic protects us also from another issue, an endless loop reported by Hugh Dickins when reclaim races with root removal and css_tryget called by iterator internally would fail. There would be no other nodes to visit so __mem_cgroup_iter_next would return NULL and mem_cgroup_iter would interpret it as "start looping from root again" and so mem_cgroup_iter would loop forever internally. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Hugh Dickins <hughd@google.com> Tested-by: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: fix endless loop caused by mem_cgroup_iterMichal Hocko1-3/+14
Hugh has reported an endless loop when the hardlimit reclaim sees the same group all the time. This might happen when the reclaim races with the memcg removal. shrink_zone [rmdir root] mem_cgroup_iter(root, NULL, reclaim) // prev = NULL rcu_read_lock() mem_cgroup_iter_load last_visited = iter->last_visited // gets root || NULL css_tryget(last_visited) // failed last_visited = NULL [1] memcg = root = __mem_cgroup_iter_next(root, NULL) mem_cgroup_iter_update iter->last_visited = root; reclaim->generation = iter->generation mem_cgroup_iter(root, root, reclaim) // prev = root rcu_read_lock mem_cgroup_iter_load last_visited = iter->last_visited // gets root css_tryget(last_visited) // failed [1] The issue seemed to be introduced by commit 5f5781619718 ("memcg: relax memcg iter caching") which has replaced unconditional css_get/css_put by css_tryget/css_put for the cached iterator. This patch fixes the issue by skipping css_tryget on the root of the tree walk in mem_cgroup_iter_load and symmetrically doesn't release it in mem_cgroup_iter_update. Signed-off-by: Michal Hocko <mhocko@suse.cz> Reported-by: Hugh Dickins <hughd@google.com> Tested-by: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Greg Thelen <gthelen@google.com> Cc: <stable@vger.kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23mm, oom: prefer thread group leaders for display purposesDavid Rientjes1-7/+12
When two threads have the same badness score, it's preferable to kill the thread group leader so that the actual process name is printed to the kernel log rather than the thread group name which may be shared amongst several processes. This was the behavior when select_bad_process() used to do for_each_process(), but it now iterates threads instead and leads to ambiguity. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Greg Thelen <gthelen@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23mm/memcg: iteration skip memcgs not yet fully initializedHugh Dickins1-4/+2
It is surprising that the mem_cgroup iterator can return memcgs which have not yet been fully initialized. By accident (or trial and error?) this appears not to present an actual problem; but it may be better to prevent such surprises, by skipping memcgs not yet online. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [3.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23mm/memcg: fix last_dead_count memory wastageHugh Dickins1-1/+1
Shorten mem_cgroup_reclaim_iter.last_dead_count from unsigned long to int: it's assigned from an int and compared with an int, and adjacent to an unsigned int: so there's no point to it being unsigned long, which wasted 104 bytes in every mem_cgroup_per_zone. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: rework memcg_update_kmem_limit synchronizationVladimir Davydov1-91/+105
Currently we take both the memcg_create_mutex and the set_limit_mutex when we enable kmem accounting for a memory cgroup, which makes kmem activation events serialize with both memcg creations and other memcg limit updates (memory.limit, memory.memsw.limit). However, there is no point in such strict synchronization rules there. First, the set_limit_mutex was introduced to keep the memory.limit and memory.memsw.limit values in sync. Since memory.kmem.limit can be set independently of them, it is better to introduce a separate mutex to synchronize against concurrent kmem limit updates. Second, we take the memcg_create_mutex in order to make sure all children of this memcg will be kmem-active as well. For achieving that, it is enough to hold this mutex only while checking if memcg_has_children() though. This guarantees that if a child is added after we checked that the memcg has no children, the newly added cgroup will see its parent kmem-active (of course if the latter succeeded), and call kmem activation for itself. This patch simplifies the locking rules of memcg_update_kmem_limit() according to these considerations. [vdavydov@parallels.com: fix unintialized var warning] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: remove KMEM_ACCOUNTED_ACTIVATED flagVladimir Davydov1-27/+2
Currently we have two state bits in mem_cgroup::kmem_account_flags regarding kmem accounting activation, ACTIVATED and ACTIVE. We start kmem accounting only if both flags are set (memcg_can_account_kmem()), plus throughout the code there are several places where we check only the ACTIVE flag, but we never check the ACTIVATED flag alone. These flags are both set from memcg_update_kmem_limit() under the set_limit_mutex, the ACTIVE flag always being set after ACTIVATED, and they never get cleared. That said checking if both flags are set is equivalent to checking only for the ACTIVE flag, and since there is no ACTIVATED flag checks, we can safely remove the ACTIVATED flag, and nothing will change. Let's try to understand what was the reason for introducing these flags. The purpose of the ACTIVE flag is clear - it states that kmem should be accounting to the cgroup. The only requirement for it is that it should be set after we have fully initialized kmem accounting bits for the cgroup and patched all static branches relating to kmem accounting. Since we always check if static branch is enabled before actually considering if we should account (otherwise we wouldn't benefit from static branching), this guarantees us that we won't skip a commit or uncharge after a charge due to an unpatched static branch. Now let's move on to the ACTIVATED bit. As I proved in the beginning of this message, it is absolutely useless, and removing it will change nothing. So what was the reason introducing it? The ACTIVATED flag was introduced by commit a8964b9b84f9 ("memcg: use static branches when code not in use") in order to guarantee that static_key_slow_inc(&memcg_kmem_enabled_key) would be called only once for each memory cgroup when its kmem accounting was activated. The point was that at that time the memcg_update_kmem_limit() function's work-flow looked like this: bool must_inc_static_branch = false; cgroup_lock(); mutex_lock(&set_limit_mutex); if (!memcg->kmem_account_flags && val != RESOURCE_MAX) { /* The kmem limit is set for the first time */ ret = res_counter_set_limit(&memcg->kmem, val); memcg_kmem_set_activated(memcg); must_inc_static_branch = true; } else ret = res_counter_set_limit(&memcg->kmem, val); mutex_unlock(&set_limit_mutex); cgroup_unlock(); if (must_inc_static_branch) { /* We can't do this under cgroup_lock */ static_key_slow_inc(&memcg_kmem_enabled_key); memcg_kmem_set_active(memcg); } So that without the ACTIVATED flag we could race with other threads trying to set the limit and increment the static branching ref-counter more than once. Today we call the whole memcg_update_kmem_limit() function under the set_limit_mutex and this race is impossible. As now we understand why the ACTIVATED bit was introduced and why we don't need it now, and know that removing it will change nothing anyway, let's get rid of it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg, slab: RCU protect memcg_params for root cachesVladimir Davydov1-7/+8
We relocate root cache's memcg_params whenever we need to grow the memcg_caches array to accommodate all kmem-active memory cgroups. Currently on relocation we free the old version immediately, which can lead to use-after-free, because the memcg_caches array is accessed lock-free (see cache_from_memcg_idx()). This patch fixes this by making memcg_params RCU-protected for root caches. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: get rid of kmem_cache_dup()Vladimir Davydov1-31/+8
kmem_cache_dup() is only called from memcg_create_kmem_cache(). The latter, in fact, does nothing besides this, so let's fold kmem_cache_dup() into memcg_create_kmem_cache(). This patch also makes the memcg_cache_mutex private to memcg_create_kmem_cache(), because it is not used anywhere else. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg, slab: fix races in per-memcg cache creation/destructionVladimir Davydov1-9/+14
We obtain a per-memcg cache from a root kmem_cache by dereferencing an entry of the root cache's memcg_params::memcg_caches array. If we find no cache for a memcg there on allocation, we initiate the memcg cache creation (see memcg_kmem_get_cache()). The cache creation proceeds asynchronously in memcg_create_kmem_cache() in order to avoid lock clashes, so there can be several threads trying to create the same kmem_cache concurrently, but only one of them may succeed. However, due to a race in the code, it is not always true. The point is that the memcg_caches array can be relocated when we activate kmem accounting for a memcg (see memcg_update_all_caches(), memcg_update_cache_size()). If memcg_update_cache_size() and memcg_create_kmem_cache() proceed concurrently as described below, we can leak a kmem_cache. Asume two threads schedule creation of the same kmem_cache. One of them successfully creates it. Another one should fail then, but if memcg_create_kmem_cache() interleaves with memcg_update_cache_size() as follows, it won't: memcg_create_kmem_cache() memcg_update_cache_size() (called w/o mutexes held) (called with slab_mutex, set_limit_mutex held) ------------------------- ------------------------- mutex_lock(&memcg_cache_mutex) s->memcg_params=kzalloc(...) new_cachep=cache_from_memcg_idx(cachep,idx) // new_cachep==NULL => proceed to creation s->memcg_params->memcg_caches[i] =cur_params->memcg_caches[i] // kmem_cache_create_memcg takes slab_mutex // so we will hang around until // memcg_update_cache_size finishes, but // nothing will prevent it from succeeding so // memcg_caches[idx] will be overwritten in // memcg_register_cache! new_cachep = kmem_cache_create_memcg(...) mutex_unlock(&memcg_cache_mutex) Let's fix this by moving the check for existence of the memcg cache to kmem_cache_create_memcg() to be called under the slab_mutex and make it return NULL if so. A similar race is possible when destroying a memcg cache (see kmem_cache_destroy()). Since memcg_unregister_cache(), which clears the pointer in the memcg_caches array, is called w/o protection, we can race with memcg_update_cache_size() and omit clearing the pointer. Therefore memcg_unregister_cache() should be moved before we release the slab_mutex. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: fix possible NULL deref while traversing memcg_slab_caches listVladimir Davydov1-7/+18
All caches of the same memory cgroup are linked in the memcg_slab_caches list via kmem_cache::memcg_params::list. This list is traversed, for example, when we read memory.kmem.slabinfo. Since the list actually consists of memcg_cache_params objects, we have to convert an element of the list to a kmem_cache object using memcg_params_to_cache(), which obtains the pointer to the cache from the memcg_params::memcg_caches array of the corresponding root cache. That said the pointer to a kmem_cache in its parent's memcg_params must be initialized before adding the cache to the list, and cleared only after it has been unlinked. Currently it is vice-versa, which can result in a NULL ptr dereference while traversing the memcg_slab_caches list. This patch restores the correct order. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg, slab: fix barrier usage when accessing memcg_cachesVladimir Davydov1-14/+10
Each root kmem_cache has pointers to per-memcg caches stored in its memcg_params::memcg_caches array. Whenever we want to allocate a slab for a memcg, we access this array to get per-memcg cache to allocate from (see memcg_kmem_get_cache()). The access must be lock-free for performance reasons, so we should use barriers to assert the kmem_cache is up-to-date. First, we should place a write barrier immediately before setting the pointer to it in the memcg_caches array in order to make sure nobody will see a partially initialized object. Second, we should issue a read barrier before dereferencing the pointer to conform to the write barrier. However, currently the barrier usage looks rather strange. We have a write barrier *after* setting the pointer and a read barrier *before* reading the pointer, which is incorrect. This patch fixes this. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg, slab: clean up memcg cache initialization/destructionVladimir Davydov1-34/+30
Currently, we have rather a messy function set relating to per-memcg kmem cache initialization/destruction. Per-memcg caches are created in memcg_create_kmem_cache(). This function calls kmem_cache_create_memcg() to allocate and initialize a kmem cache and then "registers" the new cache in the memcg_params::memcg_caches array of the parent cache. During its work-flow, kmem_cache_create_memcg() executes the following memcg-related functions: - memcg_alloc_cache_params(), to initialize memcg_params of the newly created cache; - memcg_cache_list_add(), to add the new cache to the memcg_slab_caches list. On the other hand, kmem_cache_destroy() called on a cache destruction only calls memcg_release_cache(), which does all the work: it cleans the reference to the cache in its parent's memcg_params::memcg_caches, removes the cache from the memcg_slab_caches list, and frees memcg_params. Such an inconsistency between destruction and initialization paths make the code difficult to read, so let's clean this up a bit. This patch moves all the code relating to registration of per-memcg caches (adding to memcg list, setting the pointer to a cache from its parent) to the newly created memcg_register_cache() and memcg_unregister_cache() functions making the initialization and destruction paths look symmetrical. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg, slab: kmem_cache_create_memcg(): fix memleak on fail pathVladimir Davydov1-3/+8
We do not free the cache's memcg_params if __kmem_cache_create fails. Fix this. Plus, rename memcg_register_cache() to memcg_alloc_cache_params(), because it actually does not register the cache anywhere, but simply initialize kmem_cache::memcg_params. [akpm@linux-foundation.org: fix build] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGESasha Levin1-14/+14
Most of the VM_BUG_ON assertions are performed on a page. Usually, when one of these assertions fails we'll get a BUG_ON with a call stack and the registers. I've recently noticed based on the requests to add a small piece of code that dumps the page to various VM_BUG_ON sites that the page dump is quite useful to people debugging issues in mm. This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what VM_BUG_ON() does, also dumps the page before executing the actual BUG_ON. [akpm@linux-foundation.org: fix up includes] Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23memcg: do not use vmalloc for mem_cgroup allocationsVladimir Davydov1-22/+6
The vmalloc was introduced by 33327948782b ("memcgroup: use vmalloc for mem_cgroup allocation"), because at that time MAX_NUMNODES was used for defining the per-node array in the mem_cgroup structure so that the structure could be huge even if the system had the only NUMA node. The situation was significantly improved by commit 45cf7ebd5a03 ("memcg: reduce the size of struct memcg 244-fold"), which made the size of the mem_cgroup structure calculated dynamically depending on the real number of NUMA nodes installed on the system (nr_node_ids), so now there is no point in using vmalloc here: the structure is allocated rarely and on most systems its size is about 1K. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21Merge branch 'akpm' (incoming from Andrew)Linus Torvalds1-7/+10
Merge first patch-bomb from Andrew Morton: - a couple of misc things - inotify/fsnotify work from Jan - ocfs2 updates (partial) - about half of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) mm/migrate: remove unused function, fail_migrate_page() mm/migrate: remove putback_lru_pages, fix comment on putback_movable_pages mm/migrate: correct failure handling if !hugepage_migration_support() mm/migrate: add comment about permanent failure path mm, page_alloc: warn for non-blockable __GFP_NOFAIL allocation failure mm: compaction: reset scanner positions immediately when they meet mm: compaction: do not mark unmovable pageblocks as skipped in async compaction mm: compaction: detect when scanners meet in isolate_freepages mm: compaction: reset cached scanner pfn's before reading them mm: compaction: encapsulate defer reset logic mm: compaction: trace compaction begin and end memcg, oom: lock mem_cgroup_print_oom_info sched: add tracepoints related to NUMA task migration mm: numa: do not automatically migrate KSM pages mm: numa: trace tasks that fail migration due to rate limiting mm: numa: limit scope of lock for NUMA migrate rate limiting mm: numa: make NUMA-migrate related functions static lib/show_mem.c: show num_poisoned_pages when oom mm/hwpoison: add '#' to hwpoison_inject mm/memblock: use WARN_ONCE when MAX_NUMNODES passed as input parameter ...
2014-01-21Merge branch 'for-3.14' of ↵Linus Torvalds1-74/+352
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "The bulk of changes are cleanups and preparations for the upcoming kernfs conversion. - cgroup_event mechanism which is and will be used only by memcg is moved to memcg. - pidlist handling is updated so that it can be served by seq_file. Also, the list is not sorted if sane_behavior. cgroup documentation explicitly states that the file is not sorted but it has been for quite some time. - All cgroup file handling now happens on top of seq_file. This is to prepare for kernfs conversion. In addition, all operations are restructured so that they map 1-1 to kernfs operations. - Other cleanups and low-pri fixes" * 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits) cgroup: trivial style updates cgroup: remove stray references to css_id doc: cgroups: Fix typo in doc/cgroups cgroup: fix fail path in cgroup_load_subsys() cgroup: fix missing unlock on error in cgroup_load_subsys() cgroup: remove for_each_root_subsys() cgroup: implement for_each_css() cgroup: factor out cgroup_subsys_state creation into create_css() cgroup: combine css handling loops in cgroup_create() cgroup: reorder operations in cgroup_create() cgroup: make for_each_subsys() useable under cgroup_root_mutex cgroup: css iterations and css_from_dir() are safe under cgroup_mutex cgroup: unify pidlist and other file handling cgroup: replace cftype->read_seq_string() with cftype->seq_show() cgroup: attach cgroup_open_file to all cgroup files cgroup: generalize cgroup_pidlist_open_file cgroup: unify read path so that seq_file is always used cgroup: unify cgroup_write_X64() and cgroup_write_string() cgroup: remove cftype->read(), ->read_map() and ->write() hugetlb_cgroup: convert away from cftype->read() ...
2014-01-21memcg, oom: lock mem_cgroup_print_oom_infoMichal Hocko1-5/+7
mem_cgroup_print_oom_info uses a static buffer (memcg_name) to store the name of the cgroup. This is not safe as pointed out by David Rientjes because memcg oom is locked only for its hierarchy and nothing prevents another parallel hierarchy to trigger oom as well and overwrite the already in-use buffer. This patch introduces oom_info_lock hidden inside mem_cgroup_print_oom_info which is held throughout the function. It makes access to memcg_name safe and as a bonus it also prevents parallel memcg ooms to interleave their statistics which would make the printed data hard to analyze otherwise. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21memcg: make memcg_update_cache_sizes() staticVladimir Davydov1-1/+1
This function is not used outside of memcontrol.c so make it static. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-21memcg: fix kmem_account_flags check in memcg_can_account_kmem()Vladimir Davydov1-1/+2
We should start kmem accounting for a memory cgroup only after both its kmem limit is set (KMEM_ACCOUNTED_ACTIVE) and related call sites are patched (KMEM_ACCOUNTED_ACTIVATED). Currently memcg_can_account_kmem() allows kmem accounting even if only one of the conditions is true. Fix it. This means that a page might get charged by memcg_kmem_newpage_charge which would see its static key patched already but memcg_kmem_commit_charge would still see it unpatched and so the charge won't be committed. The result would be charge inconsistency (page_cgroup not marked as PageCgroupUsed) and the charge would leak because __memcg_kmem_uncharge_pages would ignore it. [mhocko@suse.cz: augment changelog] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-02memcg: fix memcg_size() calculationVladimir Davydov1-1/+1
The mem_cgroup structure contains nr_node_ids pointers to mem_cgroup_per_node objects, not the objects themselves. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@openvz.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12mm: memcg: do not allow task about to OOM kill to bypass the limitJohannes Weiner1-1/+1
Commit 4942642080ea ("mm: memcg: handle non-error OOM situations more gracefully") allowed tasks that already entered a memcg OOM condition to bypass the memcg limit on subsequent allocation attempts hoping this would expedite finishing the page fault and executing the kill. David Rientjes is worried that this breaks memcg isolation guarantees and since there is no evidence that the bypass actually speeds up fault processing just change it so that these subsequent charge attempts fail outright. The notable exception being __GFP_NOFAIL charges which are required to bypass the limit regardless. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-bt: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12mm: memcg: fix race condition between memcg teardown and swapinJohannes Weiner1-0/+36
There is a race condition between a memcg being torn down and a swapin triggered from a different memcg of a page that was recorded to belong to the exiting memcg on swapout (with CONFIG_MEMCG_SWAP extension). The result is unreclaimable pages pointing to dead memcgs, which can lead to anything from endless loops in later memcg teardown (the page is charged to all hierarchical parents but is not on any LRU list) or crashes from following the dangling memcg pointer. Memcgs with tasks in them can not be torn down and usually charges don't show up in memcgs without tasks. Swapin with the CONFIG_MEMCG_SWAP extension is the notable exception because it charges the cgroup that was recorded as owner during swapout, which may be empty and in the process of being torn down when a task in another memcg triggers the swapin: teardown: swapin: lookup_swap_cgroup_id() rcu_read_lock() mem_cgroup_lookup() css_tryget() rcu_read_unlock() disable css_tryget() call_rcu() offline_css() reparent_charges() res_counter_charge() (hierarchical!) css_put() css_free() pc->mem_cgroup = dead memcg add page to dead lru Add a final reparenting step into css_free() to make sure any such raced charges are moved out of the memcg before it's finally freed. In the longer term it would be cleaner to have the css_tryget() and the res_counter charge under the same RCU lock section so that the charge reparenting is deferred until the last charge whose tryget succeeded is visible. But this will require more invasive changes that will be harder to evaluate and backport into stable, so better defer them to a separate change set. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-12mm: memcg: do not declare OOM from __GFP_NOFAIL allocationsJohannes Weiner1-0/+3
Commit 84235de394d9 ("fs: buffer: move allocation failure loop into the allocator") started recognizing __GFP_NOFAIL in memory cgroups but forgot to disable the OOM killer. Any task that does not fail allocation will also not enter the OOM completion path. So don't declare an OOM state in this case or it'll be leaked and the task be able to bypass the limit until the next userspace-triggered page fault cleans up the OOM state. Reported-by: William Dauchy <wdauchy@gmail.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> [3.12.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-12-05cgroup: replace cftype->read_seq_string() with cftype->seq_show()Tejun Heo1-16/+12
In preparation of conversion to kernfs, cgroup file handling is updated so that it can be easily mapped to kernfs. This patch replaces cftype->read_seq_string() with cftype->seq_show() which is not limited to single_open() operation and will map directcly to kernfs seq_file interface. The conversions are mechanical. As ->seq_show() doesn't have @css and @cft, the functions which make use of them are converted to use seq_css() and seq_cft() respectively. In several occassions, e.f. if it has seq_string in its name, the function name is updated to fit the new method better. This patch does not introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Aristeu Rozanski <arozansk@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Neil Horman <nhorman@tuxdriver.com>
2013-12-05memcg: convert away from cftype->read() and ->read_map()Tejun Heo1-28/+21
In preparation of conversion to kernfs, cgroup file handling is being consolidated so that it can be easily mapped to the seq_file based interface of kernfs. cftype->read_map() doesn't add any value and being replaced with ->read_seq_string(), and all users of cftype->read() can be easily served, usually better, by seq_file and other methods. Update mem_cgroup_read() to return u64 instead of printing itself and rename it to mem_cgroup_read_u64(), and update mem_cgroup_oom_control_read() to use ->read_seq_string() instead of ->read_map(). This patch doesn't make any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
2013-11-22cgroup: Merge branch 'memcg_event' into for-3.14Tejun Heo1-32/+321
Merge v3.12 based patch series to move cgroup_event implementation to memcg into for-3.14. The following two commits cause a conflict in kernel/cgroup.c 2ff2a7d03bbe4 ("cgroup: kill css_id") 79bd9814e5ec9 ("cgroup, memcg: move cgroup_event implementation to memcg") Each patch removes a struct definition from kernel/cgroup.c. As the two are adjacent, they cause a context conflict. Easily resolved by removing both structs. Signed-off-by: Tejun Heo <tj@kernel.org>
2013-11-22memcg: rename cgroup_event to mem_cgroup_eventTejun Heo1-20/+37
cgroup_event is only available in memcg now. Let's brand it that way. While at it, add a comment encouraging deprecation of the feature and remove the respective section from cgroup documentation. This patch is cosmetic. v3: Typo update as per Li Zefan. v2: Index in cgroups.txt updated accordingly as suggested by Li Zefan. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz>
2013-11-22memcg: make cgroup_event deal with mem_cgroup instead of cgroup_subsys_stateTejun Heo1-31/+22
cgroup_event is now memcg specific. Replace cgroup_event->css with ->memcg and convert [un]register_event() callbacks to take mem_cgroup pointer instead of cgroup_subsys_state one. This simplifies the code slightly and makes css_to_vmpressure() unnecessary which is removed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz>
2013-11-22memcg: remove cgroup_event->cftTejun Heo1-30/+35
The only use of cgroup_event->cft is distinguishing "usage_in_bytes" and "memsw.usgae_in_bytes" for mem_cgroup_usage_[un]register_event(), which can be done by adding an explicit argument to the function and implementing two wrappers so that the two cases can be distinguished from the function alone. Remove cgroup_event->cft and the related code including [un]register_events() methods. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz>
2013-11-22cgroup, memcg: move cgroup->event_list[_lock] and event callbacks into memcgTejun Heo1-27/+60
cgroup_event is being moved from cgroup core to memcg and the implementation is already moved by the previous patch. This patch moves the data fields and callbacks. * cgroup->event_list[_lock] are moved to mem_cgroup. * cftype->[un]register_event() are moved to cgroup_event. This makes it impossible for individual cftype definitions to specify their event callbacks. This is worked around by simply hard-coding filename to event callback mapping in cgroup_write_event_control(). This is awkward and inflexible, which is actually desirable given that we don't want to grow more usages of this feature. * eventfd_ctx declaration is removed from cgroup.h, which makes vmpressure.h miss eventfd_ctx declaration. Include eventfd.h from vmpressure.h. v2: Use file name from dentry instead of cftype. This will allow removing all cftype handling in the function. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
2013-11-22memcg: cgroup_write_event_control() now knows @css is for memcgTejun Heo1-16/+11
@css for cgroup_write_event_control() is now always for memcg and the target file should be a memcg file too. Drop code which assumes @css is dummy_css and the target file may belong to different subsystems. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
2013-11-22cgroup, memcg: move cgroup_event implementation to memcgTejun Heo1-0/+248
cgroup_event is way over-designed and tries to build a generic flexible event mechanism into cgroup - fully customizable event specification for each user of the interface. This is utterly unnecessary and overboard especially in the light of the planned unified hierarchy as there's gonna be single agent. Simply generating events at fixed points, or if that's too restrictive, configureable cadence or single set of configureable points should be enough. Thankfully, memcg is the only user and gets to keep it. Replacing it with something simpler on sane_behavior is strongly recommended. This patch moves cgroup_event and "cgroup.event_control" implementation to mm/memcontrol.c. Clearing of events on cgroup destruction is moved from cgroup_destroy_locked() to mem_cgroup_css_offline(), which shouldn't make any noticeable difference. cgroup_css() and __file_cft() are exported to enable the move; however, this will soon be reverted once the event code is updated to be memcg specific. Note that "cgroup.event_control" will now exist only on the hierarchy with memcg attached to it. While this change is visible to userland, it is unlikely to be noticeable as the file has never been meaningful outside memcg. Aside from the above change, this is pure code relocation. v2: Per Li Zefan's comments, init/Kconfig updated accordingly and poll.h inclusion moved from cgroup.c to memcontrol.c. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com>
2013-11-15mm, thp: change pmd_trans_huge_lock() to return taken lockKirill A. Shutemov1-5/+5
With split ptlock it's important to know which lock pmd_trans_huge_lock() took. This patch adds one more parameter to the function to return the lock. In most places migration to new api is trivial. Exception is move_huge_pmd(): we need to take two locks if pmd tables are different. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds1-3/+3
Pull networking updates from David Miller: 1) The addition of nftables. No longer will we need protocol aware firewall filtering modules, it can all live in userspace. At the core of nftables is a, for lack of a better term, virtual machine that executes byte codes to inspect packet or metadata (arriving interface index, etc.) and make verdict decisions. Besides support for loading packet contents and comparing them, the interpreter supports lookups in various datastructures as fundamental operations. For example sets are supports, and therefore one could create a set of whitelist IP address entries which have ACCEPT verdicts attached to them, and use the appropriate byte codes to do such lookups. Since the interpreted code is composed in userspace, userspace can do things like optimize things before giving it to the kernel. Another major improvement is the capability of atomically updating portions of the ruleset. In the existing netfilter implementation, one has to update the entire rule set in order to make a change and this is very expensive. Userspace tools exist to create nftables rules using existing netfilter rule sets, but both kernel implementations will need to co-exist for quite some time as we transition from the old to the new stuff. Kudos to Patrick McHardy, Pablo Neira Ayuso, and others who have worked so hard on this. 2) Daniel Borkmann and Hannes Frederic Sowa made several improvements to our pseudo-random number generator, mostly used for things like UDP port randomization and netfitler, amongst other things. In particular the taus88 generater is updated to taus113, and test cases are added. 3) Support 64-bit rates in HTB and TBF schedulers, from Eric Dumazet and Yang Yingliang. 4) Add support for new 577xx tigon3 chips to tg3 driver, from Nithin Sujir. 5) Fix two fatal flaws in TCP dynamic right sizing, from Eric Dumazet, Neal Cardwell, and Yuchung Cheng. 6) Allow IP_TOS and IP_TTL to be specified in sendmsg() ancillary control message data, much like other socket option attributes. From Francesco Fusco. 7) Allow applications to specify a cap on the rate computed automatically by the kernel for pacing flows, via a new SO_MAX_PACING_RATE socket option. From Eric Dumazet. 8) Make the initial autotuned send buffer sizing in TCP more closely reflect actual needs, from Eric Dumazet. 9) Currently early socket demux only happens for TCP sockets, but we can do it for connected UDP sockets too. Implementation from Shawn Bohrer. 10) Refactor inet socket demux with the goal of improving hash demux performance for listening sockets. With the main goals being able to use RCU lookups on even request sockets, and eliminating the listening lock contention. From Eric Dumazet. 11) The bonding layer has many demuxes in it's fast path, and an RCU conversion was started back in 3.11, several changes here extend the RCU usage to even more locations. From Ding Tianhong and Wang Yufen, based upon suggestions by Nikolay Aleksandrov and Veaceslav Falico. 12) Allow stackability of segmentation offloads to, in particular, allow segmentation offloading over tunnels. From Eric Dumazet. 13) Significantly improve the handling of secret keys we input into the various hash functions in the inet hashtables, TCP fast open, as well as syncookies. From Hannes Frederic Sowa. The key fundamental operation is "net_get_random_once()" which uses static keys. Hannes even extended this to ipv4/ipv6 fragmentation handling and our generic flow dissector. 14) The generic driver layer takes care now to set the driver data to NULL on device removal, so it's no longer necessary for drivers to explicitly set it to NULL any more. Many drivers have been cleaned up in this way, from Jingoo Han. 15) Add a BPF based packet scheduler classifier, from Daniel Borkmann. 16) Improve CRC32 interfaces and generic SKB checksum iterators so that SCTP's checksumming can more cleanly be handled. Also from Daniel Borkmann. 17) Add a new PMTU discovery mode, IP_PMTUDISC_INTERFACE, which forces using the interface MTU value. This helps avoid PMTU attacks, particularly on DNS servers. From Hannes Frederic Sowa. 18) Use generic XPS for transmit queue steering rather than internal (re-)implementation in virtio-net. From Jason Wang. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1622 commits) random32: add test cases for taus113 implementation random32: upgrade taus88 generator to taus113 from errata paper random32: move rnd_state to linux/random.h random32: add prandom_reseed_late() and call when nonblocking pool becomes initialized random32: add periodic reseeding random32: fix off-by-one in seeding requirement PHY: Add RTL8201CP phy_driver to realtek xtsonic: add missing platform_set_drvdata() in xtsonic_probe() macmace: add missing platform_set_drvdata() in mace_probe() ethernet/arc/arc_emac: add missing platform_set_drvdata() in arc_emac_probe() ipv6: protect for_each_sk_fl_rcu in mem_check with rcu_read_lock_bh vlan: Implement vlan_dev_get_egress_qos_mask as an inline. ixgbe: add warning when max_vfs is out of range. igb: Update link modes display in ethtool netfilter: push reasm skb through instead of original frag skbs ip6_output: fragment outgoing reassembled skb properly MAINTAINERS: mv643xx_eth: take over maintainership from Lennart net_sched: tbf: support of 64bit rates ixgbe: deleting dfwd stations out of order can cause null ptr deref ixgbe: fix build err, num_rx_queues is only available with CONFIG_RPS ...
2013-11-13Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds1-49/+48
Merge first patch-bomb from Andrew Morton: "Quite a lot of other stuff is banked up awaiting further next->mainline merging, but this batch contains: - Lots of random misc patches - OCFS2 - Most of MM - backlight updates - lib/ updates - printk updates - checkpatch updates - epoll tweaking - rtc updates - hfs - hfsplus - documentation - procfs - update gcov to gcc-4.7 format - IPC" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits) ipc, msg: fix message length check for negative values ipc/util.c: remove unnecessary work pending test devpts: plug the memory leak in kill_sb ./Makefile: export initial ramdisk compression config option init/Kconfig: add option to disable kernel compression drivers: w1: make w1_slave::flags long to avoid memory corruption drivers/w1/masters/ds1wm.cuse dev_get_platdata() drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page() drivers/memstick/core/mspro_block.c: fix attributes array allocation drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr kernel/panic.c: reduce 1 byte usage for print tainted buffer gcov: reuse kbasename helper kernel/gcov/fs.c: use pr_warn() kernel/module.c: use pr_foo() gcov: compile specific gcov implementation based on gcc version gcov: add support for gcc 4.7 gcov format gcov: move gcov structs definitions to a gcc version specific file kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener() kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end() kernel/sysctl_binary.c: use scnprintf() instead of snprintf() ...
2013-11-13Merge branch 'for-3.13' of ↵Linus Torvalds1-26/+40
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup changes from Tejun Heo: "Not too much activity this time around. css_id is finally killed and a minor update to device_cgroup" * 'for-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: device_cgroup: remove can_attach cgroup: kill css_id memcg: stop using css id memcg: fail to create cgroup if the cgroup id is too big memcg: convert to use cgroup id memcg: convert to use cgroup_is_descendant()
2013-11-13memcg, kmem: use cache_from_memcg_idx instead of hard codeQiang Huang1-6/+6
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13memcg, kmem: use is_root_cache instead of hard codeQiang Huang1-1/+2
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13memcg: support hierarchical memory.numa_statsYing Han1-0/+17
The memory.numa_stat file was not hierarchical. Memory charged to the children was not shown in parent's numa_stat. This change adds the "hierarchical_" stats to the existing stats. The new hierarchical stats include the sum of all children's values in addition to the value of the memcg. Tested: Create cgroup a, a/b and run workload under b. The values of b are included in the "hierarchical_*" under a. $ cd /sys/fs/cgroup $ echo 1 > memory.use_hierarchy $ mkdir a a/b Run workload in a/b: $ (echo $BASHPID >> a/b/cgroup.procs && cat /some/file && bash) & The hierarchical_ fields in parent (a) show use of workload in a/b: $ cat a/memory.numa_stat total=0 N0=0 N1=0 N2=0 N3=0 file=0 N0=0 N1=0 N2=0 N3=0 anon=0 N0=0 N1=0 N2=0 N3=0 unevictable=0 N0=0 N1=0 N2=0 N3=0 hierarchical_total=908 N0=552 N1=317 N2=39 N3=0 hierarchical_file=850 N0=549 N1=301 N2=0 N3=0 hierarchical_anon=58 N0=3 N1=16 N2=39 N3=0 hierarchical_unevictable=0 N0=0 N1=0 N2=0 N3=0 $ cat a/b/memory.numa_stat total=908 N0=552 N1=317 N2=39 N3=0 file=850 N0=549 N1=301 N2=0 N3=0 anon=58 N0=3 N1=16 N2=39 N3=0 unevictable=0 N0=0 N1=0 N2=0 N3=0 hierarchical_total=908 N0=552 N1=317 N2=39 N3=0 hierarchical_file=850 N0=549 N1=301 N2=0 N3=0 hierarchical_anon=58 N0=3 N1=16 N2=39 N3=0 hierarchical_unevictable=0 N0=0 N1=0 N2=0 N3=0 Signed-off-by: Ying Han <yinghan@google.com> Signed-off-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13memcg: refactor mem_control_numa_stat_show()Greg Thelen1-34/+22
Refactor mem_control_numa_stat_show() to use a new stats structure for smaller and simpler code. This consolidates nearly identical code. text data bss dec hex filename 8,137,679 1,703,496 1,896,448 11,737,623 b31a17 vmlinux.before 8,136,911 1,703,496 1,896,448 11,736,855 b31717 vmlinux.after Signed-off-by: Greg Thelen <gthelen@google.com> Signed-off-by: Ying Han <yinghan@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13mm: add a helper function to check may oom conditionQiang Huang1-8/+1
Use helper function to check if we need to deal with oom condition. Signed-off-by: Qiang Huang <h.huangqiang@huawei.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-27 16:20:30 +0000