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[CI] drm/i915: Replace kmap() with kmap_local_page()

Message ID 20230619084423.1971233-1-tvrtko.ursulin@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series [CI] drm/i915: Replace kmap() with kmap_local_page() | expand

Commit Message

Tvrtko Ursulin June 19, 2023, 8:44 a.m. UTC 
From: Sumitra Sharma <sumitraartsy@gmail.com>

kmap() has been deprecated in favor of the kmap_local_page()
due to high cost, restricted mapping space, the overhead of a
global lock for synchronization, and making the process sleep
in the absence of free slots.

kmap_local_page() is faster than kmap() and offers thread-local
and CPU-local mappings, take pagefaults in a local kmap region
and preserves preemption by saving the mappings of outgoing tasks
and restoring those of the incoming one during a context switch.

The mapping is kept thread local in the function
“i915_vma_coredump_create” in i915_gpu_error.c

Therefore, replace kmap() with kmap_local_page().

Suggested-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
 drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index ec368e700235..4749f99e6320 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1173,9 +1173,9 @@  i915_vma_coredump_create(const struct intel_gt *gt,
 
 			drm_clflush_pages(&page, 1);
 
-			s = kmap(page);
+			s = kmap_local_page(page);
 			ret = compress_page(compress, s, dst, false);
-			kunmap(page);
+			kunmap_local(s);
 
 			drm_clflush_pages(&page, 1);