lkml.org 
[lkml]   [2021]   [Oct]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC 2/3] mm/vmalloc: add support for __GFP_NOFAIL
On Wed, Oct 20, 2021 at 4:06 PM Michal Hocko <mhocko@suse.com> wrote:
>
> On Wed 20-10-21 15:54:23, Uladzislau Rezki wrote:
> > > > >
> > > > I think adding kind of schedule() will not make things worse and in corner
> > > > cases could prevent a power drain by CPU. It is important for mobile devices.
> > >
> > > I suspect you mean schedule_timeout here? Or cond_resched? I went with a
> > > later for now, I do not have a good idea for how to long to sleep here.
> > > I am more than happy to change to to a sleep though.
> > >
> > cond_resched() reschedules only if TIF_NEED_RESCHED is raised what is not good
> > here. Because in our case we know that we definitely would like to
> > take a breath. Therefore
> > invoking the schedule() is more suitable here. It will give a CPU time
> > to another waiting
> > process(if exists) in any case putting the "current" one to the tail.
>
> Yes, but there is no explicit event to wait for currently.
>
> > As for adding a delay. I am not sure about for how long to delay or i
> > would say i do not
> > see a good explanation why for example we delay for 10 milliseconds or so.
>
> As I've said I am OK with either of the two. Do you or anybody have any
> preference? Without any explicit event to wake up for neither of the two
> is more than just an optimistic retry.
>
From power perspective it is better to have a delay, so i tend to say
that delay is better.

--
Uladzislau Rezki

\
 
 \ /
  Last update: 2021-10-20 16:32    [W:0.094 / U:2.376 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site