lkml.org 
[lkml]   [2015]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH][RT] xfs: Disable preemption when grabbing all icsb counter locks
On Thu, Apr 30, 2015 at 12:33:03PM -0400, Steven Rostedt wrote:
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 51435dbce9c4..dbaa1ce3f308 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -1660,6 +1660,12 @@ xfs_icsb_lock_all_counters(
> xfs_icsb_cnts_t *cntp;
> int i;
>
> + /*
> + * In PREEMPT_RT, preemption is not disabled here, and it
> + * must be to take the xfs_icsb_lock_cntr.
> + */
> + preempt_disable_rt();
> +
> for_each_online_cpu(i) {
> cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
> xfs_icsb_lock_cntr(cntp);
> @@ -1677,6 +1683,8 @@ xfs_icsb_unlock_all_counters(
> cntp = (xfs_icsb_cnts_t *)per_cpu_ptr(mp->m_sb_cnts, i);
> xfs_icsb_unlock_cntr(cntp);
> }
> +
> + preempt_enable_rt();
> }

The irony, this is distinctly non deterministic code you're putting
under a RT specific preempt_disable ;-)


\
 
 \ /
  Last update: 2015-04-30 20:21    [W:0.084 / U:0.732 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site