From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3D02C433E1 for ; Mon, 18 May 2020 12:45:13 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id C6CC820674 for ; Mon, 18 May 2020 12:45:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="YZNW8bKz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C6CC820674 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JWI8VmGigSwy/MYXqaGyklulDQtFVGJsg9LVzqW0s6A=; b=YZNW8bKzV9K+nk D+JAGihNProX+cseY3wnHN2xM8EazzOIMJ3MZHS1/GLz0kXlE+nD78Zkxr5wz/jHQ6x1IgA7asefV Cf3HbGP5kO3Csp/dXr4cozQYhYdafovMm3bWWEyyfEcn5wtSMMt8ru3sxnQGQwDB6p6c3Hl8jj4Qc k04wbI/VA0kRFqPgr4fZ7r+Ck2vqnpUsme95O7ItPnuslwmN1TlfR7P36k9GDeSsoW3PvJJ5GSRll fjI/dsAdS9BYIAPwuXkayom2UldOA/r0hEwq/u2EoVzloytRD6Bnq/jhuL0z1Ez9i8sSXjbTTvzKo wEw8vyAhqWXAkQeq9kZQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jaf8q-00007y-Ln; Mon, 18 May 2020 12:45:12 +0000 Received: from cloudserver094114.home.pl ([79.96.170.134]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jaf8n-0007jp-8I for linux-arm-kernel@lists.infradead.org; Mon, 18 May 2020 12:45:10 +0000 Received: from 89-64-86-21.dynamic.chello.pl (89.64.86.21) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.415) id 49b173e4072387ec; Mon, 18 May 2020 14:45:07 +0200 From: "Rafael J. Wysocki" To: James Morse Subject: Re: [PATCH v2 1/3] mm/memory-failure: Add memory_failure_queue_kick() Date: Mon, 18 May 2020 14:45:05 +0200 Message-ID: <49686237.p6yG9EJavU@kreacher> In-Reply-To: <20200501164543.24423-2-james.morse@arm.com> References: <20200501164543.24423-1-james.morse@arm.com> <20200501164543.24423-2-james.morse@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200518_054509_476857_12C86A3C X-CRM114-Status: GOOD ( 16.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Tony Luck , linux-acpi@vger.kernel.org, Catalin Marinas , Xie XiuQi , linux-mm@kvack.org, Tyler Baicar , Borislav Petkov , Naoya Horiguchi , Will Deacon , Andrew Morton , linux-arm-kernel@lists.infradead.org, Len Brown Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Friday, May 1, 2020 6:45:41 PM CEST James Morse wrote: > The GHES code calls memory_failure_queue() from IRQ context to schedule > work on the current CPU so that memory_failure() can sleep. > > For synchronous memory errors the arch code needs to know any signals > that memory_failure() will trigger are pending before it returns to > user-space, possibly when exiting from the IRQ. > > Add a helper to kick the memory failure queue, to ensure the scheduled > work has happened. This has to be called from process context, so may > have been migrated from the original cpu. Pass the cpu the work was > queued on. > > Change memory_failure_work_func() to permit being called on the 'wrong' > cpu. > > Signed-off-by: James Morse > Tested-by: Tyler Baicar > --- > include/linux/mm.h | 1 + > mm/memory-failure.c | 15 ++++++++++++++- > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 5a323422d783..c606dbbfa5e1 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -3012,6 +3012,7 @@ enum mf_flags { > }; > extern int memory_failure(unsigned long pfn, int flags); > extern void memory_failure_queue(unsigned long pfn, int flags); > +extern void memory_failure_queue_kick(int cpu); > extern int unpoison_memory(unsigned long pfn); > extern int get_hwpoison_page(struct page *page); > #define put_hwpoison_page(page) put_page(page) > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index a96364be8ab4..c4afb407bf0f 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1493,7 +1493,7 @@ static void memory_failure_work_func(struct work_struct *work) > unsigned long proc_flags; > int gotten; > > - mf_cpu = this_cpu_ptr(&memory_failure_cpu); > + mf_cpu = container_of(work, struct memory_failure_cpu, work); > for (;;) { > spin_lock_irqsave(&mf_cpu->lock, proc_flags); > gotten = kfifo_get(&mf_cpu->fifo, &entry); > @@ -1507,6 +1507,19 @@ static void memory_failure_work_func(struct work_struct *work) > } > } > > +/* > + * Process memory_failure work queued on the specified CPU. > + * Used to avoid return-to-userspace racing with the memory_failure workqueue. > + */ > +void memory_failure_queue_kick(int cpu) > +{ > + struct memory_failure_cpu *mf_cpu; > + > + mf_cpu = &per_cpu(memory_failure_cpu, cpu); > + cancel_work_sync(&mf_cpu->work); > + memory_failure_work_func(&mf_cpu->work); > +} > + > static int __init memory_failure_init(void) > { > struct memory_failure_cpu *mf_cpu; > I could apply this provided an ACK from the mm people. Thanks! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel