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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 294DBC56202 for ; Thu, 26 Nov 2020 15:56:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7B8A221D46 for ; Thu, 26 Nov 2020 15:56:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VPOLJXTx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B8A221D46 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 631836B0074; Thu, 26 Nov 2020 10:56:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5E29B6B0075; Thu, 26 Nov 2020 10:56:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4AA8D6B0078; Thu, 26 Nov 2020 10:56:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0008.hostedemail.com [216.40.44.8]) by kanga.kvack.org (Postfix) with ESMTP id 2F0E36B0074 for ; Thu, 26 Nov 2020 10:56:08 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id EA5A18249980 for ; Thu, 26 Nov 2020 15:56:07 +0000 (UTC) X-FDA: 77527020774.06.gate75_320657d27380 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin06.hostedemail.com (Postfix) with ESMTP id A53A11003C38C for ; Thu, 26 Nov 2020 15:56:07 +0000 (UTC) X-HE-Tag: gate75_320657d27380 X-Filterd-Recvd-Size: 2538 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Thu, 26 Nov 2020 15:56:06 +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=Qz4o1lO69kgW02RmX+EDGr87UNMxuLYtFUOYFYrec8c=; b=VPOLJXTxQnz/Knjtl/blwvOkoG VylHSRv9gdJNTpdLzdXbVUt/ajOlUiXFNWLm0bFErMrUWmTiE7OwmLWmMS98pTIzhZXABsivIWc4j RK+/ADZI9JHg6VPlinBCXRJ6SLXGqj3uEejJXxLXlGV8srF0bUN677DEIbDeeu5ofjju0EPNdOvRm apMHdTUkCkp9CyZ1LoSHYiG19wpwsKVVYQd/vnw8jL8yS5IGiPHiMoqZ29N90qrc3xCKWUMIMRSHZ WHCfPlWO8YE+ZtVDnzQj69Uq+THybVy463Z/gaRyjE34ms/77I3nYgDkdQ30TjZYgEEohJWPaBE+T 3XmIdxmg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kiJcf-0007k5-OK; Thu, 26 Nov 2020 15:55:53 +0000 Date: Thu, 26 Nov 2020 15:55:53 +0000 From: Matthew Wilcox To: Vlastimil Babka Cc: Yu Zhao , Alex Shi , Konstantin Khlebnikov , Andrew Morton , Hugh Dickins , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH next] mm/swap.c: reduce lock contention in lru_cache_add Message-ID: <20201126155553.GT4327@casper.infradead.org> References: <1605860847-47445-1-git-send-email-alex.shi@linux.alibaba.com> <20201126045234.GA1014081@google.com> <20201126072402.GA1047005@google.com> <464fa387-9dfd-a8c7-3d86-040f26fd4115@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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, Nov 26, 2020 at 04:44:04PM +0100, Vlastimil Babka wrote: > However, Matthew wanted to increase pagevec size [1] and once 15^2 becomes > 63^2, it starts to be somewhat more worrying. > > [1] https://lore.kernel.org/linux-mm/20201105172651.2455-1-willy@infradead.org/ Well, Tim wanted it ;-) I would suggest that rather than an insertion sort (or was it a bubble sort?), we should be using a Shell sort. It's ideal for these kinds of smallish arrays. https://en.wikipedia.org/wiki/Shellsort