lkml.org 
[lkml]   [2013]   [Apr]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -mm -next] ipc,sem: untangle RCU locking with find_alloc_undo
On 04/05/2013 12:38 AM, Mike Galbraith wrote:
> On Tue, 2013-03-26 at 16:00 -0400, Rik van Riel wrote:

>> The ipc semaphore code has a nasty RCU locking tangle, with both
>> find_alloc_undo and semtimedop taking the rcu_read_lock(). The
>> code can be cleaned up somewhat by only taking the rcu_read_lock
>> once.
>>
>> There are no other callers to find_alloc_undo.
>>
>> This should also solve the trinity issue reported by Sasha Levin.
>
> I take it this is on top of the patchlet Sasha submitted?

Indeed, and all the other fixes that got submitted :)

> (I hit rcu stall banging on patch set in rt with 60 synchronized core
> executive model if I let it run long enough, fwtw)

What are you using to trigger an rcu stall?

>> Reported-by: Sasha Levin <sasha.levin@oracle.com>
>> Signed-off-by: Rik van Riel <riel@redhat.com>

--
All rights reversed.


\
 
 \ /
  Last update: 2013-04-05 16:01    [W:1.985 / U:0.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site