From a0442461f2caa406ce77261214ec3217fe3cac22 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 29 Apr 2016 09:07:05 +0100 Subject: [PATCH] drm/i915: Trim the flush for the legacy request emission At the start of request emission, we flush some space for the request, estimating the typical size for the request body. The tail is now much larger than the typical body, so we can shrink the flush slightly. Signed-off-by: Chris Wilson Reviewed-by: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/1461917226-9132-2-git-send-email-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_ringbuffer.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index b5e79ac2..c7637ce 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -34,6 +34,11 @@ #include "i915_trace.h" #include "intel_drv.h" +/* Rough estimate of the typical request size, performing a flush, + * set-context and then emitting the batch. + */ +#define LEGACY_REQUEST_SIZE 200 + int __intel_ring_space(int head, int tail, int size) { int space = head - tail; @@ -2345,7 +2350,7 @@ int intel_ring_alloc_request_extras(struct drm_i915_gem_request *request) * we start building the request - in which case we will just * have to repeat work. */ - request->reserved_space += MIN_SPACE_FOR_ADD_REQUEST; + request->reserved_space += LEGACY_REQUEST_SIZE; request->ringbuf = request->engine->buffer; @@ -2353,7 +2358,7 @@ int intel_ring_alloc_request_extras(struct drm_i915_gem_request *request) if (ret) return ret; - request->reserved_space -= MIN_SPACE_FOR_ADD_REQUEST; + request->reserved_space -= LEGACY_REQUEST_SIZE; return 0; } -- 2.7.4