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From: "cvs-commit at gcc dot gnu.org" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sourceware.org Subject: [Bug libc/28033] Need to check RTM_ALWAYS_ABORT for RTM Date: Tue, 01 Feb 2022 14:08:14 +0000 [thread overview] Message-ID: <bug-28033-131-5RU7r7kDXP@http.sourceware.org/bugzilla/> (raw) In-Reply-To: <bug-28033-131@http.sourceware.org/bugzilla/> https://sourceware.org/bugzilla/show_bug.cgi?id=28033 --- Comment #3 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> --- The release/2.33/master branch has been updated by H.J. Lu <hjl@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0a5f5e2dc1223c1defd6421c0cceb12883d5ad07 commit 0a5f5e2dc1223c1defd6421c0cceb12883d5ad07 Author: H.J. Lu <hjl.tools@gmail.com> Date: Wed Jun 30 10:47:06 2021 -0700 x86: Check RTM_ALWAYS_ABORT for RTM [BZ #28033] From https://www.intel.com/content/www/us/en/support/articles/000059422/processors.html * Intel TSX will be disabled by default. * The processor will force abort all Restricted Transactional Memory (RTM) transactions by default. * A new CPUID bit CPUID.07H.0H.EDX[11](RTM_ALWAYS_ABORT) will be enumerated, which is set to indicate to updated software that the loaded microcode is forcing RTM abort. * On processors that enumerate support for RTM, the CPUID enumeration bits for Intel TSX (CPUID.07H.0H.EBX[11] and CPUID.07H.0H.EBX[4]) continue to be set by default after microcode update. * Workloads that were benefited from Intel TSX might experience a change in performance. * System software may use a new bit in Model-Specific Register (MSR) 0x10F TSX_FORCE_ABORT[TSX_CPUID_CLEAR] functionality to clear the Hardware Lock Elision (HLE) and RTM bits to indicate to software that Intel TSX is disabled. 1. Add RTM_ALWAYS_ABORT to CPUID features. 2. Set RTM usable only if RTM_ALWAYS_ABORT isn't set. This skips the string/tst-memchr-rtm etc. testcases on the affected processors, which always fail after a microcde update. 3. Check RTM feature, instead of usability, against /proc/cpuinfo. This fixes BZ #28033. (cherry picked from commit ea8e465a6b8d0f26c72bcbe453a854de3abf68ec) -- You are receiving this mail because: You are on the CC list for the bug.
next prev parent reply other threads:[~2022-02-01 14:08 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-30 17:34 [Bug libc/28033] New: " hjl.tools at gmail dot com 2021-07-01 17:53 ` [Bug libc/28033] " cvs-commit at gcc dot gnu.org 2021-07-01 18:07 ` hjl.tools at gmail dot com 2022-02-01 14:08 ` cvs-commit at gcc dot gnu.org [this message] 2022-02-01 15:26 ` cvs-commit at gcc dot gnu.org 2022-02-01 15:36 ` cvs-commit at gcc dot gnu.org 2022-02-01 15:59 ` cvs-commit at gcc dot gnu.org 2022-02-01 16:06 ` cvs-commit at gcc dot gnu.org 2022-02-01 17:16 ` cvs-commit at gcc dot gnu.org
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