From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751218AbdJDWGE (ORCPT ); Wed, 4 Oct 2017 18:06:04 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:42408 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751135AbdJDWGA (ORCPT ); Wed, 4 Oct 2017 18:06:00 -0400 Date: Wed, 4 Oct 2017 15:05:53 -0700 From: "Paul E. McKenney" To: mingo@kernel.org Cc: mathieu.desnoyers@efficios.com, peterz@infradead.org, boqun.feng@gmail.com, ahh@google.com, maged.michael@gmail.com, gromer@google.com, avi@scylladb.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, davejwatson@fb.com, stern@rowland.harvard.edu, will.deacon@arm.com, luto@kernel.org, mingo@redhat.com, viro@zeniv.linux.org.uk, npiggin@gmail.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [GIT PULL membarrier/urgent] membarrier commits for 4.14 Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17100422-2213-0000-0000-00000225FBB6 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007844; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000233; SDB=6.00926545; UDB=6.00466108; IPR=6.00706757; BA=6.00005620; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00017395; XFM=3.00000015; UTC=2017-10-04 22:05:58 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17100422-2214-0000-0000-000057C0AA38 Message-Id: <20171004220553.GA16154@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-10-04_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1710040305 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Ingo, This urgent pull request contains three commits that fix a problem that arose when designing requested extensions to sys_membarrier() to allow JITs to efficiently flush old code from instruction caches. Several potential algorithms are much less painful if the user register intent to use this functionality early on, for example, before the process spawns the second thread. Registering at this time removes the need to interrupt each and every thread in that process at the first expedited sys_membarrier() system call. However, if we let the current function out, then user programs might be written without registration, which would make it more difficult to add required registration after the fact. Hence the late-in-merge-window pull request. These have been subject to 0day test robot and -next testing and are available in the git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git urgent-for-mingo for you to fetch changes up to 204a0fa1a3ecd9244869fa67608ad4fda232cba1: membarrier: Document scheduler barrier requirements (2017-10-04 11:02:18 -0700) ---------------------------------------------------------------- Mathieu Desnoyers (3): membarrier: Provide register expedited private command membarrier: selftest: Test private expedited cmd membarrier: Document scheduler barrier requirements MAINTAINERS | 2 + arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/membarrier.h | 43 ++++++++ arch/powerpc/include/asm/thread_info.h | 3 + arch/powerpc/kernel/Makefile | 2 + arch/powerpc/kernel/membarrier.c | 45 +++++++++ arch/powerpc/mm/mmu_context.c | 7 ++ arch/x86/mm/tlb.c | 5 + fs/exec.c | 1 + include/linux/mm_types.h | 3 + include/linux/sched/mm.h | 55 +++++++++++ include/uapi/linux/membarrier.h | 23 +++-- init/Kconfig | 3 + kernel/fork.c | 2 + kernel/sched/core.c | 47 +++++---- kernel/sched/membarrier.c | 25 ++++- .../testing/selftests/membarrier/membarrier_test.c | 109 ++++++++++++++++++--- 17 files changed, 329 insertions(+), 47 deletions(-) create mode 100644 arch/powerpc/include/asm/membarrier.h create mode 100644 arch/powerpc/kernel/membarrier.c