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author | Eric Dumazet <edumazet@google.com> | 2015-12-03 19:12:07 (GMT) |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-01-09 07:56:10 (GMT) |
commit | 3cc4a84e026e8d61b7ffe4a7367ed09a555f2c5b (patch) | |
tree | d538f2cde041d28d7ca3320d0e88d592cb76abad /fs/proc | |
parent | bc51b2a9193f917f2065313d9971d7d5e867bc81 (diff) | |
download | linux-3cc4a84e026e8d61b7ffe4a7367ed09a555f2c5b.tar.xz |
proc: add a reschedule point in proc_readfd_common()
User can pass an arbitrary large buffer to getdents().
It is typically a 32KB buffer used by libc scandir() implementation.
When scanning /proc/{pid}/fd, we can hold cpu way too long,
so add a cond_resched() to be kind with other tasks.
We've seen latencies of more than 50ms on real workloads.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/proc')
-rw-r--r-- | fs/proc/fd.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 3c2a915..56afa5e 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -258,6 +258,7 @@ static int proc_readfd_common(struct file *file, struct dir_context *ctx, name, len, instantiate, p, (void *)(unsigned long)fd)) goto out_fd_loop; + cond_resched(); rcu_read_lock(); } rcu_read_unlock(); |