diff options
| author | H.J. Lu <hjl.tools@gmail.com> | 2016-05-10 05:42:49 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2016-05-14 09:19:01 -0700 |
| commit | 4292da19f08b9d5e804909232489622bee6a60e3 (patch) | |
| tree | cb1ce5dd222b533113b65d75a039ef8e7d60d358 | |
| parent | 1fa001e37c3c62748b5ab00c30f9f3f0c7209286 (diff) | |
| download | glibc-4292da19f08b9d5e804909232489622bee6a60e3.tar.gz glibc-4292da19f08b9d5e804909232489622bee6a60e3.tar.xz glibc-4292da19f08b9d5e804909232489622bee6a60e3.zip | |
X86: Add cache info to _dl_x86_cpu_features hjl/ld.so/master
This patch adds cache info to _dl_x86_cpu_features to allow a processor to override cache info derived from CPUID. Tested on x86 and x86-64. * sysdeps/x86/cacheinfo.c: Skip if not in libc. (init_cacheinfo): Use raw_data_size, raw_shared_size and shared_non_temporal_threshold from _dl_x86_cpu_features if not zero. * sysdeps/x86/cpu-features.h (cache_info): New. (cpu_features): Add cache.
| -rw-r--r-- | sysdeps/x86/cacheinfo.c | 17 | ||||
| -rw-r--r-- | sysdeps/x86/cpu-features.h | 13 |
2 files changed, 29 insertions, 1 deletions
diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c index 8408624ea4..e00e19f91e 100644 --- a/sysdeps/x86/cacheinfo.c +++ b/sysdeps/x86/cacheinfo.c @@ -16,6 +16,8 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#if IS_IN (libc) + #include <assert.h> #include <stdbool.h> #include <stdlib.h> @@ -656,6 +658,11 @@ init_cacheinfo (void) #endif } + const struct cache_info *cache = &GLRO(dl_x86_cpu_features).cache; + + if (cache->raw_data_size != 0) + data = cache->raw_data_size; + if (data > 0) { __x86_raw_data_cache_size_half = data / 2; @@ -666,6 +673,9 @@ init_cacheinfo (void) __x86_data_cache_size = data; } + if (cache->raw_shared_size != 0) + shared = cache->raw_shared_size; + if (shared > 0) { __x86_raw_shared_cache_size_half = shared / 2; @@ -679,5 +689,10 @@ init_cacheinfo (void) /* The large memcpy micro benchmark in glibc shows that 6 times of shared cache size is the approximate value above which non-temporal store becomes faster. */ - __x86_shared_non_temporal_threshold = __x86_shared_cache_size * 6; + __x86_shared_non_temporal_threshold + = (cache->shared_non_temporal_threshold != 0 + ? cache->shared_non_temporal_threshold + : __x86_shared_cache_size * 6); } + +#endif diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h index 9529d61ff5..335d96a3e1 100644 --- a/sysdeps/x86/cpu-features.h +++ b/sysdeps/x86/cpu-features.h @@ -164,6 +164,18 @@ #else /* __ASSEMBLER__ */ +struct cache_info +{ + /* Data cache size for use in memory and string routines, typically + L1 size. */ + long int raw_data_size; + /* Shared cache size for use in memory and string routines, typically + L2 or L3 size. */ + long int raw_shared_size; + /* Threshold to use non temporal store. */ + long int shared_non_temporal_threshold; +}; + enum { COMMON_CPUID_INDEX_1 = 0, @@ -193,6 +205,7 @@ struct cpu_features unsigned int family; unsigned int model; unsigned int feature[FEATURE_INDEX_MAX]; + struct cache_info cache; }; /* Used from outside of glibc to get access to the CPU features |