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=-0.9 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID 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 090F3C4321D for ; Fri, 17 Aug 2018 14:38:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AB4CA2188F for ; Fri, 17 Aug 2018 14:38:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ZhVzzKVh"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="ZhVzzKVh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB4CA2188F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727604AbeHQRlj (ORCPT ); Fri, 17 Aug 2018 13:41:39 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:54344 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727428AbeHQRlj (ORCPT ); Fri, 17 Aug 2018 13:41:39 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 355656263A; Fri, 17 Aug 2018 14:38:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1534516683; bh=KvZGDdI9d79Ko9aMMWkqgXqJw+ZjKYPwalxl+JD2cUg=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=ZhVzzKVhLWF172f9sCRXDBqHINCZV939r1UYoTuhzxbOSU1/a7t9aDIk7mynu5qg5 Zqq89blxeBNDl82NezNGh0r1+xOVlwDWQ1scFBKNVpGZaRFF+UHjXA9ukP9zO6byXD Cp8x+4JI6xJ36hB/pWKsC2fNZUgcI2azFVYqwNe0= Received: from [10.204.79.100] (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mojha@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id BF3A1622CE; Fri, 17 Aug 2018 14:38:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1534516683; bh=KvZGDdI9d79Ko9aMMWkqgXqJw+ZjKYPwalxl+JD2cUg=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=ZhVzzKVhLWF172f9sCRXDBqHINCZV939r1UYoTuhzxbOSU1/a7t9aDIk7mynu5qg5 Zqq89blxeBNDl82NezNGh0r1+xOVlwDWQ1scFBKNVpGZaRFF+UHjXA9ukP9zO6byXD Cp8x+4JI6xJ36hB/pWKsC2fNZUgcI2azFVYqwNe0= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org BF3A1622CE Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=mojha@codeaurora.org Subject: Re: Query on shrink list To: Al Viro Cc: linux-fsdevel@vger.kernel.org, lkml References: <301a5546-d326-d78e-3be6-41b5a6a08c0e@codeaurora.org> <20180817125812.GC6515@ZenIV.linux.org.uk> From: Mukesh Ojha Message-ID: Date: Fri, 17 Aug 2018 20:07:59 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20180817125812.GC6515@ZenIV.linux.org.uk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/17/2018 6:28 PM, Al Viro wrote: > On Fri, Aug 17, 2018 at 03:39:22PM +0530, Mukesh Ojha wrote: >> Hi Al Viro, >> >> Is there is reason we have kept data->found++, if the dentry already there >> in shrink list ? >> >> static enum d_walk_ret select_collect( >> ... >>         if (dentry->d_flags & DCACHE_SHRINK_LIST) { >>                 data->found++; >>         } else { >>   .. >> >> If the dentry is already there on shrink list, does it not mean that >> data->found is already non-zero ? > Nope. It can be on *another* shrink list - if two processes are doing > that... Ok, if we go out simply,  letting others to do the job will break `shrink_dcache_parent()` and if someone touched that dentry made the refcount > 0 while it is on shrink list  then owner will keep on looping in shrink_dentry_list() until refcount becomes 0 . Am i making sense here ? Thanks. Mukesh > >> Can't we just go out from here directly?