From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f72.google.com (mail-oi0-f72.google.com [209.85.218.72]) by kanga.kvack.org (Postfix) with ESMTP id B45DD6B0023 for ; Thu, 15 Feb 2018 13:59:26 -0500 (EST) Received: by mail-oi0-f72.google.com with SMTP id u6so309565oie.18 for ; Thu, 15 Feb 2018 10:59:26 -0800 (PST) Received: from foss.arm.com (usa-sjc-mx-foss1.foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id t3si893714otf.362.2018.02.15.10.59.25 for ; Thu, 15 Feb 2018 10:59:25 -0800 (PST) From: James Morse Subject: [PATCH 10/11] mm/memory-failure: increase queued recovery work's priority Date: Thu, 15 Feb 2018 18:56:05 +0000 Message-Id: <20180215185606.26736-11-james.morse@arm.com> In-Reply-To: <20180215185606.26736-1-james.morse@arm.com> References: <20180215185606.26736-1-james.morse@arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-acpi@vger.kernel.org Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Borislav Petkov , Christoffer Dall , Marc Zyngier , Catalin Marinas , Will Deacon , Naoya Horiguchi , Rafael Wysocki , Len Brown , Tony Luck , Tyler Baicar , Dongjiu Geng , Xie XiuQi , Punit Agrawal , James Morse arm64 can take an NMI-like error notification when user-space steps in some corrupt memory. APEI's GHES code will call memory_failure_queue() to schedule the recovery work. We then return to user-space, possibly taking the fault again. Currently the arch code unconditionally signals user-space from this path, so we don't get stuck in this loop, but the affected process never benefits from memory_failure()s recovery work. To fix this we need to know the recovery work will run before we get back to user-space. Increase the priority of the recovery work by scheduling it on the system_highpri_wq, then try to bump the current task off this CPU so that the recover work starts immediately. Reported-by: Xie XiuQi Signed-off-by: James Morse CC: Xie XiuQi CC: gengdongjiu --- mm/memory-failure.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 4b80ccee4535..14f44d841e8b 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include #include "internal.h" @@ -1319,6 +1320,7 @@ static DEFINE_PER_CPU(struct memory_failure_cpu, memory_failure_cpu); */ void memory_failure_queue(unsigned long pfn, int flags) { + int cpu = smp_processor_id(); struct memory_failure_cpu *mf_cpu; unsigned long proc_flags; struct memory_failure_entry entry = { @@ -1328,11 +1330,14 @@ void memory_failure_queue(unsigned long pfn, int flags) mf_cpu = &get_cpu_var(memory_failure_cpu); spin_lock_irqsave(&mf_cpu->lock, proc_flags); - if (kfifo_put(&mf_cpu->fifo, entry)) - schedule_work_on(smp_processor_id(), &mf_cpu->work); - else + if (kfifo_put(&mf_cpu->fifo, entry)) { + queue_work_on(cpu, system_highpri_wq, &mf_cpu->work); + set_tsk_need_resched(current); + preempt_set_need_resched(); + } else { pr_err("Memory failure: buffer overflow when queuing memory failure at %#lx\n", pfn); + } spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); put_cpu_var(memory_failure_cpu); } -- 2.15.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org