diff options
author | Andrew Morton <akpm@linux-foundation.org> | 2013-02-07 12:32:09 +1100 |
---|---|---|
committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-02-14 15:26:40 +1100 |
commit | 3f7545686ee7e39193b674a99706ce95b73396f8 (patch) | |
tree | d9528fba0cc280cb1a507b8c6aa1465bc5f017a9 /include | |
parent | 567f919cda22befb6d1deb2691adb675406a4e8b (diff) |
generic-dynamic-per-cpu-refcounting-doc-fix
a little tidy
Cc: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/percpu-refcount.h | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index bed9a0d29f66..d0cf8872dc43 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -21,19 +21,18 @@ * BACKGROUND: * * Percpu refcounts are quite useful for performance, but if we blindly - * converted all refcounts to percpu counters we'd waste quite a bit of memory - * think about all the refcounts embedded in kobjects, files, etc. most of which - * aren't used much. + * converted all refcounts to percpu counters we'd waste quite a bit of memory. * - * These start out as simple atomic counters - a little bigger than a bare - * atomic_t, 16 bytes instead of 4 - but if we exceed some arbitrary number of - * gets in one second, we then switch to percpu counters. + * Think about all the refcounts embedded in kobjects, files, etc. most of which + * aren't used much. These start out as simple atomic counters - a little bigger + * than a bare atomic_t, 16 bytes instead of 4 - but if we exceed some arbitrary + * number of gets in one second, we then switch to percpu counters. * * This heuristic isn't perfect because it'll fire if the refcount was only * being used on one cpu; ideally we'd be able to count the number of cache * misses on percpu_ref_get() or something similar, but that'd make the non * percpu path significantly heavier/more complex. We can count the number of - * gets() without any extra atomic instructions, on arches that support + * gets() without any extra atomic instructions on arches that support * atomic64_t - simply by changing the atomic_inc() to atomic_add_return(). * * USAGE: |