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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 33D65C3F2D2 for ; Fri, 28 Feb 2020 17:48:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F14CA246AC for ; Fri, 28 Feb 2020 17:48:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F14CA246AC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 92D5E6B0007; Fri, 28 Feb 2020 12:48:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 88F686B0008; Fri, 28 Feb 2020 12:48:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A56E6B000A; Fri, 28 Feb 2020 12:48:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 6088B6B0007 for ; Fri, 28 Feb 2020 12:48:30 -0500 (EST) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 3364C5DC2 for ; Fri, 28 Feb 2020 17:48:30 +0000 (UTC) X-FDA: 76540270380.20.lake63_10004ec6b7b1e X-HE-Tag: lake63_10004ec6b7b1e X-Filterd-Recvd-Size: 3942 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf48.hostedemail.com (Postfix) with ESMTP for ; Fri, 28 Feb 2020 17:48:29 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E3DA8FEC; Fri, 28 Feb 2020 09:48:28 -0800 (PST) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.105]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 10AD13F7B4; Fri, 28 Feb 2020 09:48:26 -0800 (PST) From: James Morse To: linux-mm@kvack.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Andrew Morton , Naoya Horiguchi , Rafael Wysocki , Len Brown , Tony Luck , Borislav Petkov , Catalin Marinas , Will Deacon , Mark Rutland , Tyler Baicar , Xie XiuQi , James Morse Subject: [PATCH 1/3] mm/memory-failure: Add memory_failure_queue_kick() Date: Fri, 28 Feb 2020 17:48:15 +0000 Message-Id: <20200228174817.74278-2-james.morse@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200228174817.74278-1-james.morse@arm.com> References: <20200228174817.74278-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 --- 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 52269e56c514..389460de3ee6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2806,6 +2806,7 @@ 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 41c634f45d45..afdf1fd5ef9c 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1468,7 +1468,7 @@ static void memory_failure_work_func(struct work_st= ruct *work) unsigned long proc_flags; int gotten; =20 - mf_cpu =3D this_cpu_ptr(&memory_failure_cpu); + mf_cpu =3D container_of(work, struct memory_failure_cpu, work); for (;;) { spin_lock_irqsave(&mf_cpu->lock, proc_flags); gotten =3D kfifo_get(&mf_cpu->fifo, &entry); @@ -1482,6 +1482,19 @@ static void memory_failure_work_func(struct work_s= truct *work) } } =20 +/* + * Process memory_failure work queued on the specified CPU. + * Used to avoid return-to-userspace racing with the memory_failure work= queue. + */ +void memory_failure_queue_kick(int cpu) +{ + struct memory_failure_cpu *mf_cpu; + + mf_cpu =3D &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; --=20 2.24.1