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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 896DEC4727F for ; Fri, 25 Sep 2020 20:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3DA2722211 for ; Fri, 25 Sep 2020 20:21:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="XJv80MM1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726309AbgIYUVt (ORCPT ); Fri, 25 Sep 2020 16:21:49 -0400 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:63553 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728778AbgIYUTq (ORCPT ); Fri, 25 Sep 2020 16:19:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1601065185; x=1632601185; h=from:subject:to:cc:references:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=GHHDInrwsavPs8gmYpvoKhvNpX26ELB7NaKPCnphfu0=; b=XJv80MM1TutIWCcWsLrvBiW44khhJXzN1u2CJL4jNDq4kf0G4OfKsCwc Qp8CxMUeo/zf7O7cUfiyWrrGFYVhsPwDCD2y5+Hj9l8+V1bnhVN6PlcTW oX6AKYRM0x5YmNysEqpTMhZncMtObD3cY1KDnlbzL00rJCdXzMS4oF0vs g=; X-IronPort-AV: E=Sophos;i="5.77,303,1596499200"; d="scan'208";a="71193806" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 25 Sep 2020 19:26:15 +0000 Received: from EX13MTAUWA001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id 00B42A209D; Fri, 25 Sep 2020 19:26:13 +0000 (UTC) Received: from EX13D12UWA002.ant.amazon.com (10.43.160.88) by EX13MTAUWA001.ant.amazon.com (10.43.160.118) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 25 Sep 2020 19:26:13 +0000 Received: from uba0035656cf856.ant.amazon.com (10.43.161.146) by EX13D12UWA002.ant.amazon.com (10.43.160.88) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Fri, 25 Sep 2020 19:26:13 +0000 From: "Chen, Xiaoyi" Subject: Re: [PATCH] PM: Batch hibernate and resume IO requests To: "Rafael J. Wysocki" CC: Pavel Machek , "linux-pm@vger.kernel.org" , "Agarwal, Anchal" , "Duncan, David" , Dave Chinner , Eric Sandeen References: Message-ID: <667ded38-06a6-d058-ca22-a53eed384fd4@amazon.com> Date: Fri, 25 Sep 2020 20:26:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.43.161.146] X-ClientProxiedBy: EX13D23UWA001.ant.amazon.com (10.43.160.68) To EX13D12UWA002.ant.amazon.com (10.43.160.88) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 9/25/20 4:27 PM, Rafael J. Wysocki wrote: > > > On Tue, Sep 22, 2020 at 6:19 PM Chen, Xiaoyi wrote: >> >> >> Hibernate and resume process submits individual IO requests for each page >> of the data. With this patch, we use blk_plug to improve the batching of >> these requests. >> >> Tested this patch with hibernate and resumes, and consistently observed the >> merging of the IO requests. We see more than an order of magnitude >> improvement in hibernate and resume speed. >> >> One hibernate and resume cycle for 16GB used RAM out of 32GB takes around >> 21 minutes before the change, and 1 minutes after the change on systems >> with limited storage IOPS. >> >> Signed-off-by: Xiaoyi Chen >> Signed-off-by: Anchal Agarwal >> --- >> kernel/power/swap.c | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/kernel/power/swap.c b/kernel/power/swap.c >> index 01e2858b5fe3..961615365b5c 100644 >> --- a/kernel/power/swap.c >> +++ b/kernel/power/swap.c >> @@ -226,6 +226,7 @@ struct hib_bio_batch { >> atomic_t count; >> wait_queue_head_t wait; >> blk_status_t error; >> + struct blk_plug plug; >> }; >> >> static void hib_init_batch(struct hib_bio_batch *hb) >> @@ -233,6 +234,12 @@ static void hib_init_batch(struct hib_bio_batch *hb) >> atomic_set(&hb->count, 0); >> init_waitqueue_head(&hb->wait); >> hb->error = BLK_STS_OK; >> + blk_start_plug(&hb->plug); >> +} >> + >> +static void hib_finish_batch(struct hib_bio_batch *hb) >> +{ >> + blk_finish_plug(&hb->plug); >> } >> >> static void hib_end_io(struct bio *bio) >> @@ -294,6 +301,10 @@ static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr, >> >> static blk_status_t hib_wait_io(struct hib_bio_batch *hb) >> { >> + /* >> + * We are relying on the behavior of blk_plug that a thread with >> + * a plug will flush the plug list before sleeping. >> + */ >> wait_event(hb->wait, atomic_read(&hb->count) == 0); >> return blk_status_to_errno(hb->error); >> } >> @@ -561,6 +572,7 @@ static int save_image(struct swap_map_handle *handle, >> nr_pages++; >> } >> err2 = hib_wait_io(&hb); >> + hib_finish_batch(&hb); >> stop = ktime_get(); >> if (!ret) >> ret = err2; >> @@ -854,6 +866,7 @@ static int save_image_lzo(struct swap_map_handle *handle, >> pr_info("Image saving done\n"); >> swsusp_show_speed(start, stop, nr_to_write, "Wrote"); >> out_clean: >> + hib_finish_batch(&hb); >> if (crc) { >> if (crc->thr) >> kthread_stop(crc->thr); >> @@ -1084,6 +1097,7 @@ static int load_image(struct swap_map_handle *handle, >> nr_pages++; >> } >> err2 = hib_wait_io(&hb); >> + hib_finish_batch(&hb); >> stop = ktime_get(); >> if (!ret) >> ret = err2; >> @@ -1447,6 +1461,7 @@ static int load_image_lzo(struct swap_map_handle *handle, >> } >> swsusp_show_speed(start, stop, nr_to_read, "Read"); >> out_clean: >> + hib_finish_batch(&hb); >> for (i = 0; i < ring_size; i++) >> free_page((unsigned long)page[i]); >> if (crc) { >> -- > > Applied as 5.10 material with some subject and changelog edits, but: > 1. The patch is white-space-damaged and I needed to fix that up > manually which was not fun. > 2. I dropped the second S-o-b, because it was not clear to me whether > a Co-developed-by tag was missing or Reviewed-by should have been used > instead. > > Thanks! > Thanks for the prompt review. Apologies for the white-space and tags issues, will do better next time. Would you mind adding following tags if not too late? Signed-off-by: Anchal Agarwal Co-Developed-by: Anchal Agarwal