lkml.org 
[lkml]   [2008]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [RFC][PATCH] lru_add_drain_all() don't use schedule_on_each_cpu()
    Date
    > > On Mon, 2008-10-27 at 12:14 +0900, KOSAKI Motohiro wrote:
    > > > > Right, and would be about 4k+sizeof(task_struct), some people might be
    > > > > bothered, but most won't care.
    > > > >
    > > > > > Perhaps, I misunderstand your intension. so can you point your
    > > > > > previous discussion url?
    > > > >
    > > > > my google skillz fail me, but once in a while people complain that we
    > > > > have too many kernel threads.
    > > > >
    > > > > Anyway, if we can re-use this per-cpu workqueue for more goals, I guess
    > > > > there is even less of an objection.
    > > >
    > > > In general, you are right.
    > > > but this is special case. mmap_sem is really widely used various subsystem and drivers.
    > > > (because page fault via copy_user introduce to depend on mmap_sem)
    > > >
    > > > Then, any work-queue reu-sing can cause similar dead-lock easily.
    > >
    > > Yeah, I know, and the cpu-hotplug discussion needed another thread due
    > > to yet another locking incident. I was hoping these two could go
    > > together.
    >
    > Yeah, I found its thread. (I think it is "work_on_cpu: helper for doing task on a CPU.", right?)
    > So I'll read it soon.
    >
    > Please wait a bit.

    Done.

    Now, I think smp_call_function() is better for this issue.
    I'll try it.

    Thanks a lot.

    > > Neither are general-purpose workqueues, both need to stay away from the
    > > normal eventd due to deadlocks.
    > >
    > > ego, does you extra thread ever use mmap_sem?
    >
    >
    >





    \
     
     \ /
      Last update: 2008-10-27 11:47    [W:3.276 / U:0.600 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site