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| author | Zwane Mwaikambo <zwane@arm.linux.org.uk> | 2006-01-11 22:43:09 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-01-11 19:01:57 -0800 |
| commit | 329d400f47ddfe8ff599823d739c5c5565da3207 (patch) | |
| tree | 903b45e7ebcccbbd8172e207315c036ceb70f6e8 /arch | |
| parent | 73ca5358aab55e2e29993a31f3776c54c05ae729 (diff) | |
| download | linux-3.10-329d400f47ddfe8ff599823d739c5c5565da3207.tar.gz linux-3.10-329d400f47ddfe8ff599823d739c5c5565da3207.tar.bz2 linux-3.10-329d400f47ddfe8ff599823d739c5c5565da3207.zip | |
[PATCH] x86_64/i386: Remove preempt disable calls in lowlevel IPI
I noticed that some lowlevel send_IPI_mask helpers had a hotplug/preempt
race whereupon the cpu_online_map was read before disabling preemption;
...
cpumask_t mask = cpu_online_map;
int cpu = get_cpu();
cpu_clear(cpu, mask);
...
But then i realised that there is no need for these lowlevel functions to
be going through all this trouble when all the callers are already made
hotplug/preempt safe.
Signed-off-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86_64/kernel/genapic_cluster.c | 5 | ||||
| -rw-r--r-- | arch/x86_64/kernel/genapic_flat.c | 10 |
2 files changed, 5 insertions, 10 deletions
diff --git a/arch/x86_64/kernel/genapic_cluster.c b/arch/x86_64/kernel/genapic_cluster.c index a472d62f899..43fcf62fef0 100644 --- a/arch/x86_64/kernel/genapic_cluster.c +++ b/arch/x86_64/kernel/genapic_cluster.c @@ -72,14 +72,11 @@ static void cluster_send_IPI_mask(cpumask_t mask, int vector) static void cluster_send_IPI_allbutself(int vector) { cpumask_t mask = cpu_online_map; - int me = get_cpu(); /* Ensure we are not preempted when we clear */ - cpu_clear(me, mask); + cpu_clear(smp_processor_id(), mask); if (!cpus_empty(mask)) cluster_send_IPI_mask(mask, vector); - - put_cpu(); } static void cluster_send_IPI_all(int vector) diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c index 9da3edb799e..1a2ab825be9 100644 --- a/arch/x86_64/kernel/genapic_flat.c +++ b/arch/x86_64/kernel/genapic_flat.c @@ -83,12 +83,11 @@ static void flat_send_IPI_allbutself(int vector) __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL); #else cpumask_t allbutme = cpu_online_map; - int me = get_cpu(); /* Ensure we are not preempted when we clear */ - cpu_clear(me, allbutme); + + cpu_clear(smp_processor_id(), allbutme); if (!cpus_empty(allbutme)) flat_send_IPI_mask(allbutme, vector); - put_cpu(); #endif } @@ -149,10 +148,9 @@ static void physflat_send_IPI_mask(cpumask_t cpumask, int vector) static void physflat_send_IPI_allbutself(int vector) { cpumask_t allbutme = cpu_online_map; - int me = get_cpu(); - cpu_clear(me, allbutme); + + cpu_clear(smp_processor_id(), allbutme); physflat_send_IPI_mask(allbutme, vector); - put_cpu(); } static void physflat_send_IPI_all(int vector) |