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33237fe83d
And make always supported. The configure option was added on glibc 2.25 and some features require it (such as hwcap mask, huge pages support, and lock elisition tuning). It also simplifies the build permutations. Changes from v1: * Remove glibc.rtld.dynamic_sort changes, it is orthogonal and needs more discussion. * Cleanup more code. Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
89 lines
3.2 KiB
C
89 lines
3.2 KiB
C
/* x86 cache info.
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Copyright (C) 2020-2023 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <assert.h>
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#include <unistd.h>
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#include <cpuid.h>
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#include <cpu-features.h>
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#define TUNABLE_NAMESPACE cpu
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#include <unistd.h> /* Get STDOUT_FILENO for _dl_printf. */
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#include <elf/dl-tunables.h>
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#if IS_IN (libc)
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/* Data cache size for use in memory and string routines, typically
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L1 size, rounded to multiple of 256 bytes. */
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long int __x86_data_cache_size_half attribute_hidden = 32 * 1024 / 2;
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long int __x86_data_cache_size attribute_hidden = 32 * 1024;
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/* Shared cache size for use in memory and string routines, typically
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L2 or L3 size, rounded to multiple of 256 bytes. */
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long int __x86_shared_cache_size_half attribute_hidden = 1024 * 1024 / 2;
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long int __x86_shared_cache_size attribute_hidden = 1024 * 1024;
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/* Threshold to use non temporal store. */
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long int __x86_shared_non_temporal_threshold attribute_hidden;
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/* Threshold to use Enhanced REP MOVSB. */
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long int __x86_rep_movsb_threshold attribute_hidden = 2048;
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/* Threshold to use Enhanced REP STOSB. */
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long int __x86_rep_stosb_threshold attribute_hidden = 2048;
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/* Threshold to stop using Enhanced REP MOVSB. */
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long int __x86_rep_movsb_stop_threshold attribute_hidden;
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/* A bit-wise OR of string/memory requirements for optimal performance
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e.g. X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB. These bits
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are used at runtime to tune implementation behavior. */
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int __x86_string_control attribute_hidden;
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static void
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init_cacheinfo (void)
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{
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const struct cpu_features *cpu_features = __get_cpu_features ();
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long int data = cpu_features->data_cache_size;
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/* Round data cache size to multiple of 256 bytes. */
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data = data & ~255L;
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if (data > 0)
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{
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__x86_data_cache_size_half = data / 2;
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__x86_data_cache_size = data;
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}
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long int shared = cpu_features->shared_cache_size;
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/* Round shared cache size to multiple of 256 bytes. */
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shared = shared & ~255L;
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if (shared > 0)
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{
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__x86_shared_cache_size_half = shared / 2;
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__x86_shared_cache_size = shared;
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}
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__x86_shared_non_temporal_threshold
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= cpu_features->non_temporal_threshold;
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__x86_rep_movsb_threshold = cpu_features->rep_movsb_threshold;
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__x86_rep_stosb_threshold = cpu_features->rep_stosb_threshold;
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__x86_rep_movsb_stop_threshold = cpu_features->rep_movsb_stop_threshold;
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if (CPU_FEATURES_ARCH_P (cpu_features, Avoid_Short_Distance_REP_MOVSB))
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__x86_string_control
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|= X86_STRING_CONTROL_AVOID_SHORT_DISTANCE_REP_MOVSB;
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}
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#endif
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