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| author | Glauber Costa <glommer@openvz.org> | 2013-08-28 10:17:53 +1000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2013-09-10 18:56:29 -0400 |
| commit | 55f841ce9395a72c6285fbcc4c403c0c786e1c74 (patch) | |
| tree | d64933e4976ca3fe5a83e619ba6bdc96c5690438 /include/linux/dcache.h | |
| parent | 3942c07ccf98e66b8893f396dca98f5b076f905f (diff) | |
| download | kernel-common-55f841ce9395a72c6285fbcc4c403c0c786e1c74.tar.gz kernel-common-55f841ce9395a72c6285fbcc4c403c0c786e1c74.tar.bz2 kernel-common-55f841ce9395a72c6285fbcc4c403c0c786e1c74.zip | |
super: fix calculation of shrinkable objects for small numbers
The sysctl knob sysctl_vfs_cache_pressure is used to determine which
percentage of the shrinkable objects in our cache we should actively try
to shrink.
It works great in situations in which we have many objects (at least more
than 100), because the aproximation errors will be negligible. But if
this is not the case, specially when total_objects < 100, we may end up
concluding that we have no objects at all (total / 100 = 0, if total <
100).
This is certainly not the biggest killer in the world, but may matter in
very low kernel memory situations.
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/dcache.h')
| -rw-r--r-- | include/linux/dcache.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 844a1ef387e4..59066e0b4ff1 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -395,4 +395,8 @@ static inline bool d_mountpoint(const struct dentry *dentry) extern int sysctl_vfs_cache_pressure; +static inline unsigned long vfs_pressure_ratio(unsigned long val) +{ + return mult_frac(val, sysctl_vfs_cache_pressure, 100); +} #endif /* __LINUX_DCACHE_H */ |