From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH] drm/i915: Reduce memory pressure during shrinker by preallocating swizzle pages Date: Mon, 03 Dec 2012 17:54:00 +0000 Message-ID: <6c3329$7fhhfg@orsmga002.jf.intel.com> References: <1354552259-20069-1-git-send-email-chris@chris-wilson.co.uk> <20121203172929.GM4384@phenom.ffwll.local> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 91A03E6232 for ; Mon, 3 Dec 2012 09:54:13 -0800 (PST) In-Reply-To: <20121203172929.GM4384@phenom.ffwll.local> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Daniel Vetter Cc: intel-gfx@lists.freedesktop.org List-Id: intel-gfx@lists.freedesktop.org On Mon, 3 Dec 2012 18:29:30 +0100, Daniel Vetter wrote: > On Mon, Dec 03, 2012 at 04:30:59PM +0000, Chris Wilson wrote: > > On a machine with bit17 swizzling, we need to store the bit17 of the > > physical page address in put-pages. This requires a memory allocation, > > on average less than a page, which may be difficult to satisfy is the > > request to put-pages is on behalf of the shrinker. We could allow that > > allocation to pull from the reserved memory pools, but it seems much > > safer to preallocate the array for tiled objects on affected machines. > > > > Signed-off-by: Chris Wilson > > --- > > drivers/gpu/drm/i915/i915_gem_tiling.c | 14 ++++++++++++++ > > 1 file changed, 14 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/i915_gem_tiling.c b/drivers/gpu/drm/i915/i915_gem_tiling.c > > index 8e59bb5..140ef6b 100644 > > --- a/drivers/gpu/drm/i915/i915_gem_tiling.c > > +++ b/drivers/gpu/drm/i915/i915_gem_tiling.c > > @@ -351,6 +351,20 @@ i915_gem_set_tiling(struct drm_device *dev, void *data, > > /* we have to maintain this existing ABI... */ > > args->stride = obj->stride; > > args->tiling_mode = obj->tiling_mode; > > + > > + /* Try to preallocate memory required to save swizzling on put-pages */ > > + if (dev_priv->mm.bit_6_swizzle_x == I915_BIT_6_SWIZZLE_9_10_17) { > > + if (obj->tiling_mode) { > > i915_gem_object_needs_bit17_swizzle not suitable? No, it takes the current obj->tiling_mode. Well, originally this was using args->tiling_mode, but that fell by the wayside. Still I thought it would be useful to be able to discard the memory allocated when we release the tiling. -Chris -- Chris Wilson, Intel Open Source Technology Centre