From patchwork Wed Dec 4 11:34:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: SeongJae Park X-Patchwork-Id: 11272773 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0FC83109A for ; Wed, 4 Dec 2019 11:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0E2D20637 for ; Wed, 4 Dec 2019 11:35:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="VKo6egvd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727693AbfLDLfA (ORCPT ); Wed, 4 Dec 2019 06:35:00 -0500 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:19986 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727740AbfLDLe7 (ORCPT ); Wed, 4 Dec 2019 06:34:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1575459299; x=1606995299; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=hFszrM7KiTbnME9EGJrfhQofskCo55+99bwJF65SxQo=; b=VKo6egvd72nO/10EAgpu5ZDJnu7ihtJbi7xqAzuJuCJgtKzNFdyu3sXn axcW77xQcaDYhOsANcKFtWvw8mM0oMnZJMutUrId1AUxtdf0dXvJ9m/yn yLNECJx3x7f79oTbMhdULQ/Bi3Z0uyRu/G1KKaKnCD5JpjPc3sM15GVs0 Y=; IronPort-SDR: qhYuRtZ0Yol5ruY3wIPQVvj8V7PP7DvXuyvJIH0Dg4IB71EmrDNKQjPBTijP9FyR4jjk/XWup5 68gfq8Di2HhQ== X-IronPort-AV: E=Sophos;i="5.69,277,1571702400"; d="scan'208";a="6142138" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-9ec21598.us-east-1.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 04 Dec 2019 11:34:49 +0000 Received: from EX13MTAUEA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1d-9ec21598.us-east-1.amazon.com (Postfix) with ESMTPS id A586EA2641; Wed, 4 Dec 2019 11:34:46 +0000 (UTC) Received: from EX13D31EUA004.ant.amazon.com (10.43.165.161) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 4 Dec 2019 11:34:45 +0000 Received: from u886c93fd17d25d.ant.amazon.com (10.43.162.249) by EX13D31EUA004.ant.amazon.com (10.43.165.161) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 4 Dec 2019 11:34:42 +0000 From: SeongJae Park To: , , CC: , , , , SeongJae Park Subject: [PATCH 2/2] blkback: Add a module parameter for aggressive pool shrinking duration Date: Wed, 4 Dec 2019 12:34:19 +0100 Message-ID: <20191204113419.2298-3-sjpark@amazon.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191204113419.2298-1-sjpark@amazon.com> References: <20191204113419.2298-1-sjpark@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.43.162.249] X-ClientProxiedBy: EX13D21UWB003.ant.amazon.com (10.43.161.212) To EX13D31EUA004.ant.amazon.com (10.43.165.161) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: SeongJae Park As discussed by the previous commit ("xen/blkback: Aggressively shrink page pools if a memory pressure is detected"), the aggressive pool shrinking duration should be carefully selected: ``If it is too long, free pages pool shrinking overhead can reduce the I/O performance. If it is too short, blkback will not free enough pages to reduce the memory pressure.`` That said, the proper duration would depends on given configurations and workloads. For the reason, this commit allows users to set it via a module parameter interface. Signed-off-by: SeongJae Park Suggested-by: Amit Shah --- drivers/block/xen-blkback/blkback.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c index aa1a127093e5..88c011300ee9 100644 --- a/drivers/block/xen-blkback/blkback.c +++ b/drivers/block/xen-blkback/blkback.c @@ -137,9 +137,13 @@ module_param(log_stats, int, 0644); /* * Once a memory pressure is detected, keep aggressive shrinking of the free - * page pools for this time (msec) + * page pools for this time (milliseconds) */ -#define AGGRESSIVE_SHRINKING_DURATION 1 +static int xen_blkif_aggressive_shrinking_duration = 1; +module_param_named(aggressive_shrinking_duration, + xen_blkif_aggressive_shrinking_duration, int, 0644); +MODULE_PARM_DESC(aggressive_shrinking_duration, +"Duration to do aggressive shrinking when a memory pressure is detected"); static unsigned long xen_blk_mem_pressure_end; @@ -147,7 +151,7 @@ static unsigned long blkif_shrink_count(struct shrinker *shrinker, struct shrink_control *sc) { xen_blk_mem_pressure_end = jiffies + - msecs_to_jiffies(AGGRESSIVE_SHRINKING_DURATION); + msecs_to_jiffies(xen_blkif_aggressive_shrinking_duration); return 0; }