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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 587C0C432C0 for ; Sat, 23 Nov 2019 02:33:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 05AB020726 for ; Sat, 23 Nov 2019 02:33:36 +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="UMaVsJij" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 05AB020726 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 A746E6B0540; Fri, 22 Nov 2019 21:33:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A25406B0541; Fri, 22 Nov 2019 21:33:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 93AD26B0542; Fri, 22 Nov 2019 21:33:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0168.hostedemail.com [216.40.44.168]) by kanga.kvack.org (Postfix) with ESMTP id 7A0E16B0540 for ; Fri, 22 Nov 2019 21:33:35 -0500 (EST) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 331C16118 for ; Sat, 23 Nov 2019 02:33:35 +0000 (UTC) X-FDA: 76185971190.02.tin83_3c3bcffaeb618 X-HE-Tag: tin83_3c3bcffaeb618 X-Filterd-Recvd-Size: 2935 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf25.hostedemail.com (Postfix) with ESMTP for ; Sat, 23 Nov 2019 02:33:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=nPuduIsmzT4eyNy6AgYyeWm8a3lye8lEUGi+OFLWHQE=; b=UMaVsJijpyg+a0E75vUQkK7rg XWQcUQCgvHIOltFSFQ8of0MXhAXTDQ+LEgp/aZPcsKfZWDNuJMxrT+JnVRsrnGPLN4ZTHWN/1P61s IRlUCeGaPjd+/enFAGSylVBReBSPyMYmb2poYTrDXEoIRo9Xdjp6/XFZp9AesW02vXhaItc8wJ/9q YKBaQA6k8wkdU9IdCLgjSxKrEJvzglgm7vDvCvdzkjRqsqpwUrqjCh9ObctTA1RPyVJQoU/4FQVXQ YZUp89zmv4AAxj9Sgx/hYqgCrKN0wB34ICyv7xwzPvoRtQWW68GhucrtJL9ijKCjACkcod6bd4vhd ves1wV+4w==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1iYLEj-0004Ol-JZ; Sat, 23 Nov 2019 02:33:25 +0000 Date: Fri, 22 Nov 2019 18:33:25 -0800 From: Matthew Wilcox To: "zhengbin (A)" Cc: Hugh Dickins , viro@zeniv.linux.org.uk, linux-mm@kvack.org, linux-kernel@vger.kernel.org, houtao1@huawei.com, yi.zhang@huawei.com, "J. R. Okajima" , Eric Dumazet Subject: Re: [PATCH] tmpfs: use ida to get inode number Message-ID: <20191123023325.GY20752@bombadil.infradead.org> References: <1574259798-144561-1-git-send-email-zhengbin13@huawei.com> <20191120154552.GS20752@bombadil.infradead.org> <1c64e7c2-6460-49cf-6db0-ec5f5f7e09c4@huawei.com> <5423a199-eefb-0a02-6e86-1f6210939c11@huawei.com> <20191122221327.GW20752@bombadil.infradead.org> <77f67d7a-4a93-4319-e6af-54daffcc37e2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <77f67d7a-4a93-4319-e6af-54daffcc37e2@huawei.com> User-Agent: Mutt/1.12.1 (2019-06-15) 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 Sat, Nov 23, 2019 at 10:16:39AM +0800, zhengbin (A) wrote: > By the way, percpu IDA is for reducing performance impact? This patch has 2.16% > performance degradation(Use perf to get the cost of ida_alloc_range) 2.16% degradation in your tests ... I bet Eric didn't make it so complex for only 2% performance impact. Unfortunately, he didn't give any numbers in his patch submission, but it's going to be a bigger problem on multi-socket machines than on a laptop. Eric, any memories from 2010? Commit f991bd2e14210fb93d722cb23e54991de20e8a3d if it helps.