From: Chris Wilson Date: Tue, 12 Dec 2017 18:06:52 +0000 (+0000) Subject: drm/i915: Ratelimit request allocation under oom X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=31c70f97bec3107805df0f491485e7eacbc3a3ae;p=linux.git 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 --- diff --git a/drivers/gpu/drm/i915/i915_gem_request.c b/drivers/gpu/drm/i915/i915_gem_request.c index 4d5e2b7143826..59f023bb70157 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);