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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C24CFC43603 for ; Thu, 12 Dec 2019 22:49:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7F651214AF for ; Thu, 12 Dec 2019 22:49:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7F651214AF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=stgolabs.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 245D58E0005; Thu, 12 Dec 2019 17:49:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A8CC8E0001; Thu, 12 Dec 2019 17:49:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 048108E0005; Thu, 12 Dec 2019 17:49:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id E2F7A8E0001 for ; Thu, 12 Dec 2019 17:49:13 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id A54034826 for ; Thu, 12 Dec 2019 22:49:13 +0000 (UTC) X-FDA: 76257981786.09.eyes72_8ab9d62adc617 X-HE-Tag: eyes72_8ab9d62adc617 X-Filterd-Recvd-Size: 2398 Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) by imf44.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Dec 2019 22:49:13 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7C129AB71; Thu, 12 Dec 2019 22:49:11 +0000 (UTC) Date: Thu, 12 Dec 2019 14:42:44 -0800 From: Davidlohr Bueso To: Andi Kleen Cc: Mike Kravetz , Waiman Long , Matthew Wilcox , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko Subject: Re: [PATCH v2] hugetlbfs: Disable softIRQ when taking hugetlb_lock Message-ID: <20191212224244.ohfcrvnuc7euzmzw@linux-p48b> Mail-Followup-To: Andi Kleen , Mike Kravetz , Waiman Long , Matthew Wilcox , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko References: <20191211194615.18502-1-longman@redhat.com> <4fbc39a9-2c9c-4c2c-2b13-a548afe6083c@oracle.com> <32d2d4f2-83b9-2e40-05e2-71cd07e01b80@redhat.com> <0fcce71f-bc20-0ea3-b075-46592c8d533d@oracle.com> <20191212060650.ftqq27ftutxpc5hq@linux-p48b> <871rt99qmg.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <871rt99qmg.fsf@linux.intel.com> User-Agent: NeoMutt/20180716 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: On Thu, 12 Dec 2019, Andi Kleen wrote: >Davidlohr Bueso writes: >> +void free_huge_page(struct page *page) >> +{ >> + struct hugetlb_free_page_work work; >> + >> + work.page = page; >> + INIT_WORK_ONSTACK(&work.work, free_huge_page_workfn); >> + queue_work(hugetlb_free_page_wq, &work.work); >> + >> + /* >> + * Wait until free_huge_page is done. >> + */ >> + flush_work(&work.work); >> + destroy_work_on_stack(&work.work); > >Does flushing really work in softirq context? > >Anyways, waiting seems inefficient over fire'n'forget Yep. I was only thinking about the workerfn not blocking and therefore we could wait safely, but flush_work has no such guarantees. Thanks, Davidlohr