All of lore.kernel.org
 help / color / mirror / Atom feed
From: Chris Wilson <chris@chris-wilson.co.uk>
To: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: Wait for the mutex whilst the reaper runs
Date: Wed, 10 Oct 2012 16:21:42 +0100	[thread overview]
Message-ID: <84c8a8$62f5up@orsmga001.jf.intel.com> (raw)
In-Reply-To: <1349867250-22808-1-git-send-email-chris@chris-wilson.co.uk>

On Wed, 10 Oct 2012 12:07:30 +0100, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> If the system is forced to start kswapd to recover pages, the system is
> very starved. Fortunately, kswapd is its own process context and can
> wait for the mutex.

Note this doesn't survive inspection with lockdep due to dependency upon
pfmemalloc_wait in the direct reclaim path - that is, it is possible for
__GFP_FS allocations to wait indefinitely upon kswapd (who in turn may
be waiting for the dev->struct_mutex held by the direct reclaimer). As
we don't have complete control over all allocations made whilst holding
the struct_mutex, we can't control the gfp_t to avoid the deadlock.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

      parent reply	other threads:[~2012-10-10 15:22 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-10 11:07 [PATCH] drm/i915: Wait for the mutex whilst the reaper runs Chris Wilson
2012-10-10 15:08 ` [PATCH] drm/i915: Borrow our struct_mutex for the direct reclaim Chris Wilson
2012-10-10 21:02   ` Daniel Vetter
2012-11-08 13:49   ` Ben Widawsky
2012-11-09  8:58     ` [PATCH] drm/i915: Guard pages being reaped by OOM whilst binding-to-GTT Chris Wilson
2012-11-20  9:48       ` Daniel Vetter
2012-10-10 15:21 ` Chris Wilson [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='84c8a8$62f5up@orsmga001.jf.intel.com' \
    --to=chris@chris-wilson.co.uk \
    --cc=intel-gfx@lists.freedesktop.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.