From patchwork Sat Jun 5 03:01:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 455048 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=ham 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 56BC9C4743E for ; Sat, 5 Jun 2021 03:01:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3FDC761412 for ; Sat, 5 Jun 2021 03:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230481AbhFEDDN (ORCPT ); Fri, 4 Jun 2021 23:03:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:52484 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbhFEDDM (ORCPT ); Fri, 4 Jun 2021 23:03:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DFCF2613F4; Sat, 5 Jun 2021 03:01:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1622862072; bh=5Glz9eV9ywxNKU5L2Ppl13Cqd/TaZRXGBw4LPAe1YCI=; h=Date:From:To:Subject:In-Reply-To:From; b=s5Nuh6uRQcJ7kkWtdssPcHdR3r7gXqNv0JNFp5Hfb6om5JWXKU7jW06oRACTIyLTx 5Nqpni+pFZy77evRCNskaPmnD5kF6kWZmfSgCL3jfmmzNmmK7tzt1p6xUpekUDPt2y Es1oCbfbIV6NueInMWaOsuaVzOIj3J8RJuNu9Kws= Date: Fri, 04 Jun 2021 20:01:11 -0700 From: Andrew Morton To: akpm@linux-foundation.org, David.Laight@ACULAB.COM, dvyukov@google.com, elver@google.com, glider@google.com, hdanton@sina.com, linux-mm@kvack.org, mgorman@suse.de, mm-commits@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 02/13] kfence: use TASK_IDLE when awaiting allocation Message-ID: <20210605030111.zE60Ybm3T%akpm@linux-foundation.org> In-Reply-To: <20210604200040.d8d0406caf195525620c0f3d@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marco Elver Subject: kfence: use TASK_IDLE when awaiting allocation Since wait_event() uses TASK_UNINTERRUPTIBLE by default, waiting for an allocation counts towards load. However, for KFENCE, this does not make any sense, since there is no busy work we're awaiting. Instead, use TASK_IDLE via wait_event_idle() to not count towards load. BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1185565 Link: https://lkml.kernel.org/r/20210521083209.3740269-1-elver@google.com Fixes: 407f1d8c1b5f ("kfence: await for allocation using wait_event") Signed-off-by: Marco Elver Cc: Mel Gorman Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: David Laight Cc: Hillf Danton Cc: [5.12+] Signed-off-by: Andrew Morton --- mm/kfence/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/kfence/core.c~kfence-use-task_idle-when-awaiting-allocation +++ a/mm/kfence/core.c @@ -627,10 +627,10 @@ static void toggle_allocation_gate(struc * During low activity with no allocations we might wait a * while; let's avoid the hung task warning. */ - wait_event_timeout(allocation_wait, atomic_read(&kfence_allocation_gate), - sysctl_hung_task_timeout_secs * HZ / 2); + wait_event_idle_timeout(allocation_wait, atomic_read(&kfence_allocation_gate), + sysctl_hung_task_timeout_secs * HZ / 2); } else { - wait_event(allocation_wait, atomic_read(&kfence_allocation_gate)); + wait_event_idle(allocation_wait, atomic_read(&kfence_allocation_gate)); } /* Disable static key and reset timer. */