From 31c70f97bec3107805df0f491485e7eacbc3a3ae Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 12 Dec 2017 18:06:52 +0000 Subject: [PATCH] drm/i915: Ratelimit request allocation under oom If we fail to allocate a request, we can reap the outstanding requests and push them to the request's slab's freelist before trying again. This forces us to ratelimit malicious clients that tie up all of the system resources in requests, instead of causing a system-wide oom. Testcase: igt/gem_shrink/execbuf1 Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Reviewed-by: Joonas Lahtinen Link: https://patchwork.freedesktop.org/patch/msgid/20171212180652.22061-3-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_request.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 4d5e2b714382..59f023bb7015 100644 --- a/drivers/gpu/drm/i915/i915_gem_request.c +++ b/drivers/gpu/drm/i915/i915_gem_request.c @@ -677,10 +677,21 @@ i915_gem_request_alloc(struct intel_engine_cs *engine, * * Do not use kmem_cache_zalloc() here! */ - req = kmem_cache_alloc(dev_priv->requests, GFP_KERNEL); - if (!req) { - ret = -ENOMEM; - goto err_unreserve; + req = kmem_cache_alloc(dev_priv->requests, + GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN); + if (unlikely(!req)) { + /* Ratelimit ourselves to prevent oom from malicious clients */ + ret = i915_gem_wait_for_idle(dev_priv, + I915_WAIT_LOCKED | + I915_WAIT_INTERRUPTIBLE); + if (ret) + goto err_unreserve; + + req = kmem_cache_alloc(dev_priv->requests, GFP_KERNEL); + if (!req) { + ret = -ENOMEM; + goto err_unreserve; + } } req->timeline = i915_gem_context_lookup_timeline(ctx, engine); -- 2.39.5