This is the mail archive of the
glibc-cvs@sourceware.org
mailing list for the glibc project.
GNU C Library master sources branch master updated. glibc-2.23-403-gd6af238
- From: hjl at sourceware dot org
- To: glibc-cvs at sourceware dot org
- Date: 27 May 2016 22:17:12 -0000
- Subject: GNU C Library master sources branch master updated. glibc-2.23-403-gd6af238
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".
The branch, master has been updated
via d6af2388f7085b134d289b034a9cbe21a2d5f819 (commit)
from f6ef0657e493e1f84dfb5b0b1966cf34e371ae27 (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=d6af2388f7085b134d289b034a9cbe21a2d5f819
commit d6af2388f7085b134d289b034a9cbe21a2d5f819
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 27 15:16:22 2016 -0700
Count number of logical processors sharing L2 cache
For Intel processors, when there are both L2 and L3 caches, SMT level
type should be ued to count number of available logical processors
sharing L2 cache. If there is only L2 cache, core level type should
be used to count number of available logical processors sharing L2
cache. Number of available logical processors sharing L2 cache should
be used for non-inclusive L2 and L3 caches.
* sysdeps/x86/cacheinfo.c (init_cacheinfo): Count number of
available logical processors with SMT level type sharing L2
cache for Intel processors.
diff --git a/ChangeLog b/ChangeLog
index 776b7ca..1e11464 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-05-27 H.J. Lu <hongjiu.lu@intel.com>
+
+ * sysdeps/x86/cacheinfo.c (init_cacheinfo): Count number of
+ available logical processors with SMT level type sharing L2
+ cache for Intel processors.
+
2016-05-27 Joseph Myers <joseph@codesourcery.com>
[BZ #20160]
diff --git a/sysdeps/x86/cacheinfo.c b/sysdeps/x86/cacheinfo.c
index 182426b..cf4f64b 100644
--- a/sysdeps/x86/cacheinfo.c
+++ b/sysdeps/x86/cacheinfo.c
@@ -499,11 +499,24 @@ init_cacheinfo (void)
level = 3;
shared = handle_intel (_SC_LEVEL3_CACHE_SIZE, max_cpuid);
+ /* Number of logical processors sharing L2 cache. */
+ int threads_l2;
+
+ /* Number of logical processors sharing L3 cache. */
+ int threads_l3;
+
if (shared <= 0)
{
/* Try L2 otherwise. */
level = 2;
shared = core;
+ threads_l2 = 0;
+ threads_l3 = -1;
+ }
+ else
+ {
+ threads_l2 = 0;
+ threads_l3 = 0;
}
/* A value of 0 for the HTT bit indicates there is only a single
@@ -519,7 +532,8 @@ init_cacheinfo (void)
int i = 0;
- /* Query until desired cache level is enumerated. */
+ /* Query until cache level 2 and 3 are enumerated. */
+ int check = 0x1 | (threads_l3 == 0) << 1;
do
{
__cpuid_count (4, i++, eax, ebx, ecx, edx);
@@ -530,24 +544,53 @@ init_cacheinfo (void)
assume there is no such information. */
if ((eax & 0x1f) == 0)
goto intel_bug_no_cache_info;
- }
- while (((eax >> 5) & 0x7) != level);
- /* Check if cache is inclusive of lower cache levels. */
- inclusive_cache = (edx & 0x2) != 0;
+ switch ((eax >> 5) & 0x7)
+ {
+ default:
+ break;
+ case 2:
+ if ((check & 0x1))
+ {
+ /* Get maximum number of logical processors
+ sharing L2 cache. */
+ threads_l2 = (eax >> 14) & 0x3ff;
+ check &= ~0x1;
+ }
+ break;
+ case 3:
+ if ((check & (0x1 << 1)))
+ {
+ /* Get maximum number of logical processors
+ sharing L3 cache. */
+ threads_l3 = (eax >> 14) & 0x3ff;
- threads = (eax >> 14) & 0x3ff;
+ /* Check if L2 and L3 caches are inclusive. */
+ inclusive_cache = (edx & 0x2) != 0;
+ check &= ~(0x1 << 1);
+ }
+ break;
+ }
+ }
+ while (check);
- /* If max_cpuid >= 11, THREADS is the maximum number of
- addressable IDs for logical processors sharing the
- cache, instead of the maximum number of threads
+ /* If max_cpuid >= 11, THREADS_L2/THREADS_L3 are the maximum
+ numbers of addressable IDs for logical processors sharing
+ the cache, instead of the maximum number of threads
sharing the cache. */
- if (threads && max_cpuid >= 11)
+ if (max_cpuid >= 11)
{
/* Find the number of logical processors shipped in
one core and apply count mask. */
i = 0;
- while (1)
+
+ /* Count SMT only if there is L3 cache. Always count
+ core if there is no L3 cache. */
+ int count = ((threads_l2 > 0 && level == 3)
+ | ((threads_l3 > 0
+ || (threads_l2 > 0 && level == 2)) << 1));
+
+ while (count)
{
__cpuid_count (11, i++, eax, ebx, ecx, edx);
@@ -555,36 +598,71 @@ init_cacheinfo (void)
int type = ecx & 0xff00;
if (shipped == 0 || type == 0)
break;
+ else if (type == 0x100)
+ {
+ /* Count SMT. */
+ if ((count & 0x1))
+ {
+ int count_mask;
+
+ /* Compute count mask. */
+ asm ("bsr %1, %0"
+ : "=r" (count_mask) : "g" (threads_l2));
+ count_mask = ~(-1 << (count_mask + 1));
+ threads_l2 = (shipped - 1) & count_mask;
+ count &= ~0x1;
+ }
+ }
else if (type == 0x200)
{
- int count_mask;
-
- /* Compute count mask. */
- asm ("bsr %1, %0"
- : "=r" (count_mask) : "g" (threads));
- count_mask = ~(-1 << (count_mask + 1));
- threads = (shipped - 1) & count_mask;
- break;
+ /* Count core. */
+ if ((count & (0x1 << 1)))
+ {
+ int count_mask;
+ int threads_core
+ = (level == 2 ? threads_l2 : threads_l3);
+
+ /* Compute count mask. */
+ asm ("bsr %1, %0"
+ : "=r" (count_mask) : "g" (threads_core));
+ count_mask = ~(-1 << (count_mask + 1));
+ threads_core = (shipped - 1) & count_mask;
+ if (level == 2)
+ threads_l2 = threads_core;
+ else
+ threads_l3 = threads_core;
+ count &= ~(0x1 << 1);
+ }
}
}
}
- threads += 1;
- if (threads > 2 && level == 2 && family == 6)
+ if (threads_l2 > 0)
+ threads_l2 += 1;
+ if (threads_l3 > 0)
+ threads_l3 += 1;
+ if (level == 2)
{
- switch (model)
+ if (threads_l2)
{
- case 0x37:
- case 0x4a:
- case 0x4d:
- case 0x5a:
- case 0x5d:
- /* Silvermont has L2 cache shared by 2 cores. */
- threads = 2;
- break;
- default:
- break;
+ threads = threads_l2;
+ if (threads > 2 && family == 6)
+ switch (model)
+ {
+ case 0x37:
+ case 0x4a:
+ case 0x4d:
+ case 0x5a:
+ case 0x5d:
+ /* Silvermont has L2 cache shared by 2 cores. */
+ threads = 2;
+ break;
+ default:
+ break;
+ }
}
}
+ else if (threads_l3)
+ threads = threads_l3;
}
else
{
@@ -604,8 +682,12 @@ intel_bug_no_cache_info:
}
/* Account for non-inclusive L2 and L3 caches. */
- if (level == 3 && !inclusive_cache)
- shared += core;
+ if (!inclusive_cache)
+ {
+ if (threads_l2 > 0)
+ core /= threads_l2;
+ shared += core;
+ }
}
/* This spells out "AuthenticAMD". */
else if (is_amd)
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 6 ++
sysdeps/x86/cacheinfo.c | 150 ++++++++++++++++++++++++++++++++++++-----------
2 files changed, 122 insertions(+), 34 deletions(-)
hooks/post-receive
--
GNU C Library master sources