lkml.org 
[lkml]   [2008]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] cgroup: use read lock to guard find_existing_css_set()
    Balbir Singh wrote:
    > Li Zefan wrote:
    >> The function does not modify anything (except the temporary
    >> css template), so it's sufficient to hold read lock.
    >>
    >> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
    >> ---
    >> kernel/cgroup.c | 4 ++--
    >> 1 files changed, 2 insertions(+), 2 deletions(-)
    >>
    >> diff --git a/kernel/cgroup.c b/kernel/cgroup.c
    >> index 2727f92..e9eb5da 100644
    >> --- a/kernel/cgroup.c
    >> +++ b/kernel/cgroup.c
    >> @@ -406,11 +406,11 @@ static struct css_set *find_css_set(
    >>
    >> /* First see if we already have a cgroup group that matches
    >> * the desired set */
    >> - write_lock(&css_set_lock);
    >> + read_lock(&css_set_lock);
    >> res = find_existing_css_set(oldcg, cgrp, template);
    >> if (res)
    >> get_css_set(res);
    >> - write_unlock(&css_set_lock);
    >> + read_unlock(&css_set_lock);
    >>
    >> if (res)
    >> return res;
    >
    > Looks good to me. Did you run lockdep?
    >

    No, I found this when reading the code, but I do have done some test.


    \
     
     \ /
      Last update: 2008-04-24 03:05    [W:0.025 / U:2.364 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site