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 14B7DC63798 for ; Thu, 26 Nov 2020 15:56:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88E1121D7E for ; Thu, 26 Nov 2020 15:56:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="VPOLJXTx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403920AbgKZP4K (ORCPT ); Thu, 26 Nov 2020 10:56:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391496AbgKZP4K (ORCPT ); Thu, 26 Nov 2020 10:56:10 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDE73C0613D4 for ; Thu, 26 Nov 2020 07:56:09 -0800 (PST) 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: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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