Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [Intel-gfx] [PATCH] drm/i915: Selectively enable self-reclaim | Date | Thu, 1 Jul 2010 10:55:29 +0900 (JST) |
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> On Wed, Jun 30, 2010 at 4:07 PM, Linus Torvalds > <torvalds@linux-foundation.org> wrote: > > > > That commit changes the page cache allocation to use > > > > + mapping_gfp_mask (mapping) | > > + __GFP_COLD | > > + gfpmask); > > > > if I read it right. And the default mapping_gfp_mask() is > > GFP_HIGHUSER_MOVABLE, so I think you get all of > > (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_HARDWALL | __GFP_HIGHMEM) > > set by default. > > .. and then I left out the one flag I _meant_ to have there, namely > __GFP_MOVABLE. > > > The old code didn't just play games with ~__GFP_NORETRY and change > > that at runtime (which was buggy - no locking, no protection, no > > nothing), it also initialized the gfp mask. And that code also got > > removed: > > In fact, I don't really see why we should use that mapping_gfp_mask() > at all, since all allocations should be going through that > i915_gem_object_get_pages() function anyway. So why not just change > that function to ignore the default gfp mask for the mapping, and just > use the mask that the o915 driver wants? > > Btw, why did it want to mark the pages reclaimable?
I'm not GEM expert at all. but as far as I read following documentation,
http://lwn.net/Articles/283798/
GEM memory have pin and unpin state and unpined memory can be reclaimed. but it's just guess. So, I wonder if your patch solve the issue. I don't imazine a memory state which "swap-out is safe, but compaction is unsafe".
Dave, if you have good documentation which we understand GEM memory management, could you send us?
- kosaki
> > Anyway, what I'm suggesting somebody who sees this test is just > something like the patch below (whitespace-damage - I'm cutting and > pasting, it's a trivial one-liner). Does this change any behavior? > Vefa? > > Linus > > --- > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c > index 9ded3da..ec8ed6b 100644 > --- a/drivers/gpu/drm/i915/i915_gem.c > +++ b/drivers/gpu/drm/i915/i915_gem.c > @@ -2239,7 +2239,7 @@ i915_gem_object_get_pages(struct drm_gem_object *obj, > mapping = inode->i_mapping; > for (i = 0; i < page_count; i++) { > page = read_cache_page_gfp(mapping, i, > - mapping_gfp_mask (mapping) | > + GFP_HIGHMEM | > __GFP_COLD | > gfpmask); > if (IS_ERR(page)) > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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