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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A0FAAC2D0C9 for ; Thu, 12 Dec 2019 21:32:43 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6BE6B2253D for ; Thu, 12 Dec 2019 21:32:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6BE6B2253D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0D2558E0005; Thu, 12 Dec 2019 16:32:43 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 082308E0001; Thu, 12 Dec 2019 16:32:43 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED9D58E0005; Thu, 12 Dec 2019 16:32:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0022.hostedemail.com [216.40.44.22]) by kanga.kvack.org (Postfix) with ESMTP id D8C638E0001 for ; Thu, 12 Dec 2019 16:32:42 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 8FFF13489 for ; Thu, 12 Dec 2019 21:32:42 +0000 (UTC) X-FDA: 76257788964.27.view38_34a8d40d61c13 X-HE-Tag: view38_34a8d40d61c13 X-Filterd-Recvd-Size: 2466 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Thu, 12 Dec 2019 21:32:41 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Dec 2019 13:32:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,307,1571727600"; d="scan'208";a="216426268" Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.21]) by orsmga003.jf.intel.com with ESMTP; 12 Dec 2019 13:32:39 -0800 Received: by tassilo.localdomain (Postfix, from userid 1000) id DE8C330038C; Thu, 12 Dec 2019 13:32:39 -0800 (PST) From: Andi Kleen To: Mike Kravetz Cc: 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 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> Date: Thu, 12 Dec 2019 13:32:39 -0800 In-Reply-To: <20191212060650.ftqq27ftutxpc5hq@linux-p48b> (Davidlohr Bueso's message of "Wed, 11 Dec 2019 22:06:50 -0800") Message-ID: <871rt99qmg.fsf@linux.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain 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: 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 You'll need a per cpu pre allocated work item and a queue. Then take a lock on the the queue and link the page into it and trigger the work item if it's not already pending. And add a in_interrupt() check of course. -Andi