| Message ID | 20181105170640.26905-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Break long iterations for get/put shmemfs pages | expand |
Quoting Chris Wilson (2018-11-05 19:06:40) > 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 <chris@chris-wilson.co.uk> > Cc: Kuo-Hsin Yang <vovoy@chromium.org> > Cc: Matthew Auld <matthew.auld@intel.com> > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Regards, Joonas
Quoting Joonas Lahtinen (2018-11-06 10:55:32) > Quoting Chris Wilson (2018-11-05 19:06:40) > > 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 <chris@chris-wilson.co.uk> > > Cc: Kuo-Hsin Yang <vovoy@chromium.org> > > Cc: Matthew Auld <matthew.auld@intel.com> > > Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> > > Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Applied as this improves the current syslatency, and further improves Kuo-Hsin's patch. -Chris
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index b1caff07ed65..a120112d0621 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 @@ static int i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) 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 @@ static int i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj) } i915_gem_shrink(dev_priv, 2 * page_count, NULL, *s++); - cond_resched(); /* * We've tried hard to allocate the memory by reaping
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 <chris@chris-wilson.co.uk> Cc: Kuo-Hsin Yang <vovoy@chromium.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> --- drivers/gpu/drm/i915/i915_gem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)