From e6db7f4d7c5005258b862a5ed1732756fccb6bfa Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Mon, 5 Nov 2018 17:06:40 +0000 Subject: [PATCH] drm/i915: Break long iterations for get/put shmemfs pages As we may have to iterate a few thousand elements to acquire and release the shmemfs backing storage for a GPU object, we need to break up the long loop with cond_resched() to retain a modicum of low latency for other processes. Testcase: igt/benchmarks/gem_syslatency Signed-off-by: Chris Wilson Cc: Kuo-Hsin Yang Cc: Matthew Auld Cc: Joonas Lahtinen Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20181105170640.26905-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 93d09282710d5..347b3836c8095 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2404,6 +2404,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj, mark_page_accessed(page); put_page(page); + cond_resched(); } obj->mm.dirty = false; @@ -2574,6 +2575,7 @@ rebuild_st: gfp_t gfp = noreclaim; do { + cond_resched(); page = shmem_read_mapping_page_gfp(mapping, i, gfp); if (likely(!IS_ERR(page))) break; @@ -2584,7 +2586,6 @@ rebuild_st: } i915_gem_shrink(dev_priv, 2 * page_count, NULL, *s++); - cond_resched(); /* * We've tried hard to allocate the memory by reaping -- 2.30.2