Messages in this thread | | | Date | Mon, 19 Jun 2023 09:59:50 +0200 | Subject | Re: [PATCH v2] drm/i915: Replace kmap() with kmap_local_page() | From | Thomas Hellström (Intel) <> |
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On 6/18/23 20:11, Ira Weiny wrote: > Sumitra Sharma wrote: >> 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> >> > NIT: No need for the line break between Suggested-by and your signed off line. > >> Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com> >> --- >> >> Changes in v2: >> - Replace kmap() with kmap_local_page(). > Generally it is customary to attribute a change like this to those who > suggested it in a V1 review. > > For example: > > - Tvrtko/Thomas: Use kmap_local_page() instead of page_address() > > Also I don't see Thomas on the new email list. Since he took the time to > review V1 he might want to check this version out. I've added him to the > 'To:' list.
Thanks.
> Also a link to V1 is nice. B4 formats it like this: > > - Link to v1: https://lore.kernel.org/all/20230614123556.GA381200@sumitra.com/ > > All that said the code looks good to me. So with the above changes. > > Reviewed-by: Ira Weiny <ira.weiny@intel.com>
LGTM. Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> >> - Change commit subject and message. >> >> drivers/gpu/drm/i915/i915_gpu_error.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c >> index f020c0086fbc..bc41500eedf5 100644 >> --- a/drivers/gpu/drm/i915/i915_gpu_error.c >> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c >> @@ -1164,9 +1164,9 @@ 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); >> >> -- >> 2.25.1 >>
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