forked from rpms/glibc
e43852d149
* Thu Oct 13 2022 Arjun Shankar <arjun@redhat.com> - 2.34-48 - Handle non-hostname CNAME aliases during name resolution (#2129005) - Sync with upstream branch release/2.34/master, commit e3976287b22422787f3cc6fc9adda58304b55bd9: - nscd: Drop local address tuple variable [BZ #29607] - x86-64: Require BMI1/BMI2 for AVX2 strrchr and wcsrchr implementations - x86-64: Require BMI2 and LZCNT for AVX2 memrchr implementation - x86-64: Require BMI2 for AVX2 (raw|w)memchr implementations - x86-64: Require BMI2 for AVX2 wcs(n)cmp implementations - x86-64: Require BMI2 for AVX2 strncmp implementation - x86-64: Require BMI2 for AVX2 strcmp implementation - x86-64: Require BMI2 for AVX2 str(n)casecmp implementations - x86: include BMI1 and BMI2 in x86-64-v3 level - nptl: Add backoff mechanism to spinlock loop - sysdeps: Add 'get_fast_jitter' interace in fast-jitter.h - nptl: Effectively skip CAS in spinlock loop - Move assignment out of the CAS condition - Add LLL_MUTEX_READ_LOCK [BZ #28537] - Avoid extra load with CAS in __pthread_mutex_clocklock_common [BZ #28537] - Avoid extra load with CAS in __pthread_mutex_lock_full [BZ #28537] - resolv: Fix building tst-resolv-invalid-cname for earlier C standards - nss_dns: Rewrite _nss_dns_gethostbyname4_r using current interfaces - resolv: Add new tst-resolv-invalid-cname - nss_dns: In gaih_getanswer_slice, skip strange aliases (bug 12154) (#2129005) - nss_dns: Rewrite getanswer_r to match getanswer_ptr (bug 12154, bug 29305) - nss_dns: Remove remnants of IPv6 address mapping - nss_dns: Rewrite _nss_dns_gethostbyaddr2_r and getanswer_ptr - nss_dns: Split getanswer_ptr from getanswer_r - resolv: Add DNS packet parsing helpers geared towards wire format - resolv: Add internal __ns_name_length_uncompressed function - resolv: Add the __ns_samebinaryname function - resolv: Add internal __res_binary_hnok function - resolv: Add tst-resolv-aliases - resolv: Add tst-resolv-byaddr for testing reverse lookup - gconv: Use 64-bit interfaces in gconv_parseconfdir (bug 29583) - elf: Fix hwcaps string size overestimation - nscd: Fix netlink cache invalidation if epoll is used [BZ #29415] - Apply asm redirections in wchar.h before first use - Apply asm redirections in stdio.h before first use [BZ #27087] - elf: Call __libc_early_init for reused namespaces (bug 29528) Resolves: #2129005 Resolves: #2116960
39 lines
1.3 KiB
Diff
39 lines
1.3 KiB
Diff
commit 43760d33d78f9ea8c8af942b570112ee801b99df
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Author: Jangwoong Kim <6812skiii@gmail.com>
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Date: Tue Dec 14 21:30:51 2021 +0900
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nptl: Effectively skip CAS in spinlock loop
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The commit:
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"Add LLL_MUTEX_READ_LOCK [BZ #28537]"
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SHA1: d672a98a1af106bd68deb15576710cd61363f7a6
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introduced LLL_MUTEX_READ_LOCK, to skip CAS in spinlock loop
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if atomic load fails. But, "continue" inside of do-while loop
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does not skip the evaluation of escape expression, thus CAS
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is not skipped.
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Replace do-while with while and skip LLL_MUTEX_TRYLOCK if
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LLL_MUTEX_READ_LOCK fails.
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Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
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(cherry picked from commit 6b8dbbd03ac88f169b65b5c7d7278576a11d2e44)
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diff --git a/nptl/pthread_mutex_lock.c b/nptl/pthread_mutex_lock.c
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index 49901ffa0a96d659..bbe754a272b97d91 100644
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--- a/nptl/pthread_mutex_lock.c
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+++ b/nptl/pthread_mutex_lock.c
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@@ -147,10 +147,9 @@ PTHREAD_MUTEX_LOCK (pthread_mutex_t *mutex)
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break;
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}
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atomic_spin_nop ();
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- if (LLL_MUTEX_READ_LOCK (mutex) != 0)
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- continue;
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}
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- while (LLL_MUTEX_TRYLOCK (mutex) != 0);
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+ while (LLL_MUTEX_READ_LOCK (mutex) != 0
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+ || LLL_MUTEX_TRYLOCK (mutex) != 0);
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mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
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}
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