From 8e7d2b2c6ecd3c21a54b877eae3d5be48292e6b5 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Fri, 8 May 2009 16:13:25 -0700 Subject: drm/i915: allocate large pointer arrays with vmalloc For awhile now, many of the GEM code paths have allocated page or object arrays with the slab allocator. This is nice and fast, but won't work well if memory is fragmented, since the slab allocator works with physically contiguous memory (i.e. order > 2 allocations are likely to fail fairly early after booting and doing some work). This patch works around the issue by falling back to vmalloc for >PAGE_SIZE allocations. This is ugly, but much less work than chaining a bunch of pages together by hand (suprisingly there's not a bunch of generic kernel helpers for this yet afaik). vmalloc space is somewhat precious on 32 bit kernels, but our allocations shouldn't be big enough to cause problems, though they're routinely more than a page. Note that this patch doesn't address the unchecked alloc-based-on-ioctl-args in GEM; that needs to be fixed in a separate patch. Also, I've deliberately ignored the DRM's "area" junk. I don't think anyone actually uses it anymore and I'm hoping it gets ripped out soon. [Updated: removed size arg to new free function. We could unify the free functions as well once the DRM mem tracking is ripped out.] fd.o bug #20152 (part 1/3) Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt --- include/drm/drmP.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'include/drm') diff --git a/include/drm/drmP.h b/include/drm/drmP.h index c8c422151431..b84d8ae35e6f 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1519,6 +1519,30 @@ static __inline__ void *drm_calloc(size_t nmemb, size_t size, int area) { return kcalloc(nmemb, size, GFP_KERNEL); } + +static __inline__ void *drm_calloc_large(size_t nmemb, size_t size) +{ + u8 *addr; + + if (size <= PAGE_SIZE) + return kcalloc(nmemb, size, GFP_KERNEL); + + addr = vmalloc(nmemb * size); + if (!addr) + return NULL; + + memset(addr, 0, nmemb * size); + + return addr; +} + +static __inline void drm_free_large(void *ptr) +{ + if (!is_vmalloc_addr(ptr)) + return kfree(ptr); + + vfree(ptr); +} #else extern void *drm_alloc(size_t size, int area); extern void drm_free(void *pt, size_t size, int area); -- cgit v1.2.3