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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 0DD1FC433DB for ; Thu, 25 Mar 2021 10:11:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0C2561A27 for ; Thu, 25 Mar 2021 10:11:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230138AbhCYKKo (ORCPT ); Thu, 25 Mar 2021 06:10:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:43958 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230119AbhCYKKc (ORCPT ); Thu, 25 Mar 2021 06:10:32 -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=1616667030; 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=o+O8DfigmD78cxzDLQFiEri2lafjyCUlwz+crQjIF+s=; b=WqScUkqiftCKLWBPs3UOhfC92i9LOcE0v5mjJQCiX6snpSfjtx+G/NO3zfzBzoyQL2C00x aboX26KjHcE4x0xTn2dSI/ar4d4ePMlQzNuwesqFZi+FPCDFIJJXpDC1eV2rNTP9NZ4jMC V9GpRzrxkZDymU+GPRsBMDqc73KglXo= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A9A7DAA55; Thu, 25 Mar 2021 10:10:30 +0000 (UTC) Date: Thu, 25 Mar 2021 11:10:27 +0100 From: Michal Hocko To: Oscar Salvador Cc: Mike Kravetz , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Roman Gushchin , Shakeel Butt , David Hildenbrand , Muchun Song , David Rientjes , Miaohe Lin , Peter Zijlstra , Matthew Wilcox , HORIGUCHI NAOYA , "Aneesh Kumar K . V" , Waiman Long , Peter Xu , Mina Almasry , Hillf Danton , Andrew Morton Subject: Re: [PATCH 1/8] mm: cma: introduce cma_release_nowait() Message-ID: References: <20210325002835.216118-1-mike.kravetz@oracle.com> <20210325002835.216118-2-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 Thu 25-03-21 10:54:10, Oscar Salvador wrote: > On Thu, Mar 25, 2021 at 10:45:18AM +0100, Michal Hocko wrote: > > On Wed 24-03-21 17:28:28, Mike Kravetz wrote: > > [...] > > > phys_addr_t cma_get_base(const struct cma *cma) > > > { > > > return PFN_PHYS(cma->base_pfn); > > > @@ -146,6 +155,10 @@ static int __init cma_init_reserved_areas(void) > > > for (i = 0; i < cma_area_count; i++) > > > cma_activate_area(&cma_areas[i]); > > > > > > + cma_release_wq = create_workqueue("cma_release"); > > > > Considering the workqueue is used to free up memory it should likely be > > WQ_MEM_RECLAIM to prevent from long stalls when WQs are overloaded. > > I might be missing something but the worqueue->func() seems to not be anything > for memory related purposes. > The worqueue calls cma_clear_bitmap_fn(), and the only think that does > is freeing one page, and clearing the bitmap. No, it shouldn't realease a sing page. That is a bug which I have overlooked as well. I should free up the whole count worth of pages. But fundamentally the worker does all the heavy lifting and frees up the memory. -- Michal Hocko SUSE Labs