lkml.org 
[lkml]   [2010]   [Jun]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Overview of concurrency managed workqueue
From
Date
On Wed, 2010-06-16 at 15:39 +0200, Tejun Heo wrote:
> On 06/16/2010 03:37 PM, Johannes Berg wrote:
> >> As multiple execution contexts are available for each wq, deadlocks
> >> around execution contexts is much harder to create. The default
> >> workqueue, system_wq, has maximum concurrency level of 256 and unless
> >> there is a use case which can result in a dependency loop involving
> >> more than 254 workers, it won't deadlock.
> >
> > I see a lot of stuff about the current limitations etc., but nothing
> > about code that actually _relies_ on the synchronisation properties of
> > the current wqs. We talked about that a long time ago, is it still
> > guaranteed that a single-threaded wq will serialise all work put onto
> > it? It needs to be, but I don't see you explicitly mentioning it.
>
> Oh yeah, if you have WQ_SINGLE_CPU + max inflight of 1, works on the
> wq are fully ordered.

Ok, great, thanks. FWIW, that's pretty much all I care about right
now :)

johannes



\
 
 \ /
  Last update: 2010-06-16 15:45    [from the cache]
©2003-2011 Jasper Spaans