lkml.org 
[lkml]   [2013]   [Jun]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] ipc: don't allocate with GFP_KERNEL inside rcu read lock
From
Date
On Mon, 2013-06-10 at 12:14 -0400, Sasha Levin wrote:
> ipc_addid() is protected by a rcu read lock, which means we can't allocate
> using GFP_KERNEL inside it.
>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
>
> Another option would be to call idr_preload from outside the read lock,
> but that complicates the code much more than this fix. If that's the
> preferred method to fix it I can resend that solution instead.
>

This issue was reported last week by Fengguang
(http://www.spinics.net/lists/kernel/msg1545633.html#.UbYI9qqdmV8)

Your fix looks the simplest approach, but I'm not sure if doing the
atomic allocation would trigger some other problem, as a side effect.
Andrew?

A third option would be to simply revert the offending commit, leaving
the rcu locking as it originally was.

Thanks,
Davidlohr



\
 
 \ /
  Last update: 2013-06-10 19:41    [W:0.044 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site