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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 77BDAC433C1 for ; Tue, 23 Mar 2021 12:40:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C3FA9619A5 for ; Tue, 23 Mar 2021 12:40:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3FA9619A5 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 348228D0009; Tue, 23 Mar 2021 08:40:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2F7618D0007; Tue, 23 Mar 2021 08:40:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 198808D0009; Tue, 23 Mar 2021 08:40:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0238.hostedemail.com [216.40.44.238]) by kanga.kvack.org (Postfix) with ESMTP id F0D8F8D0007 for ; Tue, 23 Mar 2021 08:40:26 -0400 (EDT) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A78768249980 for ; Tue, 23 Mar 2021 12:40:26 +0000 (UTC) X-FDA: 77951097252.10.1D2EF74 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf12.hostedemail.com (Postfix) with ESMTP id 2AC5CFE for ; Tue, 23 Mar 2021 12:40:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=rgG/bpt1t2GFpWSgbm4RR7F1V5UU5WpTGRoAtt36yEY=; b=v4vmw1hndGkuJds3H4wsnsxyd6 i+cP2BQuXuVF6Y3wkHbxK9KNVSAb+VRyDvrGqiLJGFfidmqvWq8zFSgZ2sPmNLCH0mCk5xJ5wjB2e Pjj0N0RQHKdXIZWiwHnGVtYB3+y2av0300rroUbIU3uGO5GHF708d06k4fAgMVckdeLocAR05QXF0 uUAXH0oUHyQRe7QWn7bUntWY+5BXlovDaiMUizQ7wTevF5n69k3YWyV7EZHZLjY5B45J62hTRX54d JqbjKnO8xEd76tHG92trmyU5TGGyJKwA9qK7kceqKudLFOi9fFHpLqSq4y0vEFsSjIHaqFY6yysHH VMVWPdLg==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lOgJV-00A3Ge-Ah; Tue, 23 Mar 2021 12:39:28 +0000 Date: Tue, 23 Mar 2021 12:39:13 +0000 From: Matthew Wilcox To: Uladzislau Rezki Cc: Andrew Morton , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Nicholas Piggin Subject: Re: [PATCH 2/2] mm/vmalloc: Use kvmalloc to allocate the table of pages Message-ID: <20210323123913.GD1719932@casper.infradead.org> References: <20210322193820.2140045-1-willy@infradead.org> <20210322193820.2140045-2-willy@infradead.org> <20210322223619.GA56503@pc638.lan> <20210322230311.GY1719932@casper.infradead.org> <20210323120436.GA1949@pc638.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210323120436.GA1949@pc638.lan> X-Stat-Signature: 7hk3fbjjjee9yiytwopz53mt37ck38ab X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 2AC5CFE Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf12; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1616503224-276930 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 Tue, Mar 23, 2021 at 01:04:36PM +0100, Uladzislau Rezki wrote: > On Mon, Mar 22, 2021 at 11:03:11PM +0000, Matthew Wilcox wrote: > > I suspect the vast majority of the time is spent calling alloc_pages_node() > > 1024 times. Have you looked at Mel's patch to do ... well, exactly what > > vmalloc() wants? > > > > - __vmalloc_node_range > - 45.25% __alloc_pages_nodemask > - 37.59% get_page_from_freelist [...] > - 44.61% 0xffffffffc047348d > - __vunmap > - 35.56% free_unref_page Hmm! I hadn't been thinking about the free side of things. Does this make a difference? diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4f5f8c907897..61d5b769fea0 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2277,16 +2277,8 @@ static void __vunmap(const void *addr, int deallocate_pages) vm_remove_mappings(area, deallocate_pages); if (deallocate_pages) { - int i; - - for (i = 0; i < area->nr_pages; i++) { - struct page *page = area->pages[i]; - - BUG_ON(!page); - __free_pages(page, 0); - } + release_pages(area->pages, area->nr_pages); atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); - kvfree(area->pages); } release_pages does a bunch of checks that are unnecessary ... we could probably just do: LIST_HEAD(pages_to_free); for (i = 0; i < area->nr_pages; i++) { struct page *page = area->pages[i]; if (put_page_testzero(page)) list_add(&page->lru, &pages_to_free); } free_unref_page_list(&pages_to_free); but let's see if the provided interface gets us the performance we want. > Reviewed-by: Uladzislau Rezki (Sony) > > Thanks! Thank you!