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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 385F4C433E0 for ; Mon, 22 Mar 2021 14:47:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EECDE6192B for ; Mon, 22 Mar 2021 14:47:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230229AbhCVOql (ORCPT ); Mon, 22 Mar 2021 10:46:41 -0400 Received: from mx2.suse.de ([195.135.220.15]:48104 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230139AbhCVOq1 (ORCPT ); Mon, 22 Mar 2021 10:46:27 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1616424386; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Icvrunq7s47g5UuOx3C1ykL1/UQNOPaopN5BLnKRXPs=; b=kmtnnvMkJ8AWU2nH5OpmmbR+C/wd6mZIE+1qW7VfAkrjeffS1DtbbwRtgNc/msHHnaFcoI JAjpo8Tt2kccfF+GHA/8PToU4TLpURCzaSIwT/Fc3LzteK7qXCvlMaEbbWFIIAGMxRLstT dToveiO9mjjsJTGvlsxIMzds5dOWeoQ= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 462A5ACFC; Mon, 22 Mar 2021 14:46:26 +0000 (UTC) Date: Mon, 22 Mar 2021 15:46:25 +0100 From: Michal Hocko To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Shakeel Butt , Oscar Salvador , David Hildenbrand , Muchun Song , David Rientjes , Miaohe Lin , Peter Zijlstra , Matthew Wilcox , HORIGUCHI NAOYA , "Aneesh Kumar K . V" , Waiman Long , Peter Xu , Mina Almasry , Andrew Morton Subject: Re: [RFC PATCH 7/8] hugetlb: add update_and_free_page_no_sleep for irq context Message-ID: References: <20210319224209.150047-1-mike.kravetz@oracle.com> <20210319224209.150047-8-mike.kravetz@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 22-03-21 15:42:27, Michal Hocko wrote: [...] > Besides that the changelog doesn't really say anything about changed > user visible behavior change. Now if somebody decreases the GB huge pool > from the userspace the real effect on the freed up memory will be > postponed to some later time. That "later" is unpredictable as it > depends on WQ utilization. We definitely need some sort of > wait_for_inflight pages. One way to do that would be to have a dedicated > WQ and schedule a sync work item after the pool has been shrunk and wait > for that item. Scratch that. It is not really clear from the patch context but after looking at the resulting code set_max_huge_pages will use the blockable update_and_free_page so we should be fine. Sorry about the noise! -- Michal Hocko SUSE Labs