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66 lines
3.4 KiB
66 lines
3.4 KiB
commit 89c017de2f52d17862bda9a6f8382e913457bfbe |
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Author: H.J. Lu <hjl.tools@gmail.com> |
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Date: Tue Jan 3 13:06:48 2023 -0800 |
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x86: Check minimum/maximum of non_temporal_threshold [BZ #29953] |
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The minimum non_temporal_threshold is 0x4040. non_temporal_threshold may |
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be set to less than the minimum value when the shared cache size isn't |
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available (e.g., in an emulator) or by the tunable. Add checks for |
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minimum and maximum of non_temporal_threshold. |
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This fixes BZ #29953. |
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(cherry picked from commit 48b74865c63840b288bd85b4d8743533b73b339b) |
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diff --git a/sysdeps/x86/dl-cacheinfo.h b/sysdeps/x86/dl-cacheinfo.h |
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index a7d2cc5fef03884b..f2d2de458db7358c 100644 |
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--- a/sysdeps/x86/dl-cacheinfo.h |
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+++ b/sysdeps/x86/dl-cacheinfo.h |
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@@ -747,6 +747,18 @@ dl_init_cacheinfo (struct cpu_features *cpu_features) |
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share of the cache, it has a substantial risk of negatively |
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impacting the performance of other threads running on the chip. */ |
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unsigned long int non_temporal_threshold = shared * 3 / 4; |
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+ /* SIZE_MAX >> 4 because memmove-vec-unaligned-erms right-shifts the value of |
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+ 'x86_non_temporal_threshold' by `LOG_4X_MEMCPY_THRESH` (4) and it is best |
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+ if that operation cannot overflow. Minimum of 0x4040 (16448) because the |
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+ L(large_memset_4x) loops need 64-byte to cache align and enough space for |
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+ at least 1 iteration of 4x PAGE_SIZE unrolled loop. Both values are |
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+ reflected in the manual. */ |
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+ unsigned long int maximum_non_temporal_threshold = SIZE_MAX >> 4; |
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+ unsigned long int minimum_non_temporal_threshold = 0x4040; |
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+ if (non_temporal_threshold < minimum_non_temporal_threshold) |
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+ non_temporal_threshold = minimum_non_temporal_threshold; |
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+ else if (non_temporal_threshold > maximum_non_temporal_threshold) |
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+ non_temporal_threshold = maximum_non_temporal_threshold; |
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#if HAVE_TUNABLES |
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/* NB: The REP MOVSB threshold must be greater than VEC_SIZE * 8. */ |
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@@ -801,8 +813,8 @@ dl_init_cacheinfo (struct cpu_features *cpu_features) |
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shared = tunable_size; |
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tunable_size = TUNABLE_GET (x86_non_temporal_threshold, long int, NULL); |
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- /* NB: Ignore the default value 0. */ |
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- if (tunable_size != 0) |
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+ if (tunable_size > minimum_non_temporal_threshold |
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+ && tunable_size <= maximum_non_temporal_threshold) |
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non_temporal_threshold = tunable_size; |
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tunable_size = TUNABLE_GET (x86_rep_movsb_threshold, long int, NULL); |
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@@ -817,14 +829,9 @@ dl_init_cacheinfo (struct cpu_features *cpu_features) |
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TUNABLE_SET_WITH_BOUNDS (x86_data_cache_size, data, 0, SIZE_MAX); |
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TUNABLE_SET_WITH_BOUNDS (x86_shared_cache_size, shared, 0, SIZE_MAX); |
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- /* SIZE_MAX >> 4 because memmove-vec-unaligned-erms right-shifts the value of |
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- 'x86_non_temporal_threshold' by `LOG_4X_MEMCPY_THRESH` (4) and it is best |
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- if that operation cannot overflow. Minimum of 0x4040 (16448) because the |
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- L(large_memset_4x) loops need 64-byte to cache align and enough space for |
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- at least 1 iteration of 4x PAGE_SIZE unrolled loop. Both values are |
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- reflected in the manual. */ |
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TUNABLE_SET_WITH_BOUNDS (x86_non_temporal_threshold, non_temporal_threshold, |
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- 0x4040, SIZE_MAX >> 4); |
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+ minimum_non_temporal_threshold, |
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+ maximum_non_temporal_threshold); |
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TUNABLE_SET_WITH_BOUNDS (x86_rep_movsb_threshold, rep_movsb_threshold, |
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minimum_rep_movsb_threshold, SIZE_MAX); |
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TUNABLE_SET_WITH_BOUNDS (x86_rep_stosb_threshold, rep_stosb_threshold, 1,
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