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=-12.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 B3466C433DF for ; Thu, 15 Oct 2020 15:09:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B7972080A for ; Thu, 15 Oct 2020 15:09:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="Vsjkyc1f" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389463AbgJOPJ2 (ORCPT ); Thu, 15 Oct 2020 11:09:28 -0400 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:6655 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388764AbgJOPJ2 (ORCPT ); Thu, 15 Oct 2020 11:09:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1602774568; x=1634310568; h=from:to:cc:subject:date:message-id:mime-version: in-reply-to:content-transfer-encoding; bh=xI1wCRbxJCFX6yOdKgXcnKW1y6wTWNYIfl97uYZxpXE=; b=Vsjkyc1fSH69yCRzbm7KZgLcZ4D5al/jk3pmbnVEPrp0v40cWisL8N4v 0uKrSD4N8yImivzTtD4aE07m/xbxepqapYq8lSiATPveM8XzwGKYLsGjQ EMraV5CcP6eIqI1fdu2FEyopPBxnHdwXbU571dpJJad4bEr6mHWxeULiI c=; X-IronPort-AV: E=Sophos;i="5.77,379,1596499200"; d="scan'208";a="59532495" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-1a-807d4a99.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 15 Oct 2020 15:09:21 +0000 Received: from EX13D31EUB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan3.iad.amazon.com [10.40.163.38]) by email-inbound-relay-1a-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 65806A20A0; Thu, 15 Oct 2020 15:09:18 +0000 (UTC) Received: from u3f2cd687b01c55.ant.amazon.com (10.43.160.125) by EX13D31EUB001.ant.amazon.com (10.43.166.210) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 15 Oct 2020 15:09:13 +0000 From: SeongJae Park To: Roger Pau Monne CC: , Konrad Rzeszutek Wilk , Jens Axboe , Boris Ostrovsky , SeongJae Park , , , "J . Roeleveld" , =?UTF-8?q?J=C3=BCrgen=20Gro=C3=9F?= Subject: Re: [PATCH 1/2] xen/blkback: turn the cache purge LRU interval into a parameter Date: Thu, 15 Oct 2020 17:08:49 +0200 Message-ID: <20201015150849.3844-1-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 In-Reply-To: <20201015142416.70294-2-roger.pau@citrix.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.43.160.125] X-ClientProxiedBy: EX13D02UWC003.ant.amazon.com (10.43.162.199) To EX13D31EUB001.ant.amazon.com (10.43.166.210) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, 15 Oct 2020 16:24:15 +0200 Roger Pau Monne wrote: > Assume that reads and writes to the variable will be atomic. The worse > that could happen is that one of the LRU intervals is not calculated > properly if a partially written value is read, but that would only be > a transient issue. > > Signed-off-by: Roger Pau Monné > --- > Cc: Konrad Rzeszutek Wilk > Cc: Jens Axboe > Cc: Boris Ostrovsky > Cc: SeongJae Park > Cc: xen-devel@lists.xenproject.org > Cc: linux-block@vger.kernel.org > Cc: J. Roeleveld > Cc: Jürgen Groß > --- > Documentation/ABI/testing/sysfs-driver-xen-blkback | 10 ++++++++++ > drivers/block/xen-blkback/blkback.c | 9 ++++++--- > 2 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-driver-xen-blkback b/Documentation/ABI/testing/sysfs-driver-xen-blkback > index ecb7942ff146..776f25d335ca 100644 > --- a/Documentation/ABI/testing/sysfs-driver-xen-blkback > +++ b/Documentation/ABI/testing/sysfs-driver-xen-blkback > @@ -35,3 +35,13 @@ Description: > controls the duration in milliseconds that blkback will not > cache any page not backed by a grant mapping. > The default is 10ms. > + > +What: /sys/module/xen_blkback/parameters/lru_internval > +Date: October 2020 > +KernelVersion: 5.10 > +Contact: Roger Pau Monné > +Description: > + The LRU mechanism to clean the lists of persistent grants needs > + to be executed periodically. This parameter controls the time > + interval between consecutive executions of the purge mechanism > + is set in ms. I think noticing the default value (100ms) here would be better. Thanks, SeongJae Park