From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: [GIT PULL membarrier/urgent] membarrier commits for 4.14 Date: Wed, 4 Oct 2017 15:05:53 -0700 Message-ID: <20171004220553.GA16154@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:38472 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751132AbdJDWGA (ORCPT ); Wed, 4 Oct 2017 18:06:00 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v94M3pdX027409 for ; Wed, 4 Oct 2017 18:06:00 -0400 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2dd4knsmgm-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 04 Oct 2017 18:06:00 -0400 Received: from localhost by e11.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 4 Oct 2017 18:05:59 -0400 Content-Disposition: inline Sender: linux-arch-owner@vger.kernel.org List-ID: 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 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