From patchwork Wed May 24 05:58:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yang X-Patchwork-Id: 98304 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp2624372vqo; Tue, 23 May 2023 23:05:34 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ5gpgOzmVK9RkIl76OFkvfb/zRf98XJvJsVIACtNh9Ld774QTNO0BpTjIya4ugcduDGdyZ1 X-Received: by 2002:a17:90a:c294:b0:253:572f:79b1 with SMTP id f20-20020a17090ac29400b00253572f79b1mr17154938pjt.28.1684908334269; Tue, 23 May 2023 23:05:34 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1684908334; cv=none; d=google.com; s=arc-20160816; b=BmmT4V2tVsC/xkDMAG2EiSW/Ln6J6hW5nu40QpEFN9TQUwN8ftuym8tZoHtWTBJtKX uzKVfTuQYlbJrLdlWsYvLizhZ1wI3ANSUwMmuEuhSr+t/diFFLgRLjFEHS46ZEctND0l /fKtc/empCfw9F0sml6IZXzgOiQKFJjkIuiOxCzmjgXDz9qqQ5WzsDwLl4omnGtIc1Nm WWFe4nO5gLk9p5p6n/8mf2YNn9d5G2aSu/1o09ROm4dbzbbWe3/ZprjjRLL8qCbl7URR O9DU5lcC/aoqWMIy8mTLk34u6E284YhUmxpb7SnQt4B9wYoyXQxctcqeZPdlW0v7Qv5Q 2APA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=VcL2Q4JTspmfkQxQd44Bdj2lnGJZupasdfeynoYHwIs=; b=gSWyHTGUoSccD5NKoOdG4Tju6jF1X8gx5JMpTGa3jPJAImr1jlA4w0KRyyetcVjxBl dwKJ8tx2UnhDKLnWwFCsVnVT8JkY2l8AhaWIuNK9Us1G+GFHeeu6TlUCmzURAlqJoUXP 0lC9ULP0eXeASw5X0WcDh2Dft41VH6IgXz8S0wApy31WxZLCnP8tBP3nHHAtat1aEMEi DbiNisX5Q/Ja5oIoxodf+hnTaedkdwxO96u4wJQL0SFYYv3s8yEqQj166zHP+KiSivL7 M5ivEhr7p1+JpJ7GWElTvEChircBG4WqukeuuQHXLI+CeEeqUoJ7fcRqZHeGJ4057Lvz QFIg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=zte.com.cn Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id oa13-20020a17090b1bcd00b0024df18639f4si766353pjb.72.2023.05.23.23.05.21; Tue, 23 May 2023 23:05:34 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=zte.com.cn Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239570AbjEXF7J (ORCPT + 99 others); Wed, 24 May 2023 01:59:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239521AbjEXF7H (ORCPT ); Wed, 24 May 2023 01:59:07 -0400 Received: from ubuntu20 (unknown [193.203.214.57]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13DEF18B for ; Tue, 23 May 2023 22:58:54 -0700 (PDT) Received: by ubuntu20 (Postfix, from userid 1003) id CE8E2E1EEA; Wed, 24 May 2023 13:58:52 +0800 (CST) From: Yang Yang To: akpm@linux-foundation.org, david@redhat.com Cc: yang.yang29@zte.com.cn, imbrenda@linux.ibm.com, jiang.xuexin@zte.com.cn, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ran.xiaokai@zte.com.cn, xu.xin.sc@gmail.com, xu.xin16@zte.com.cn, shr@devkernel.io Subject: [PATCH v9 4/5] ksm: consider KSM-placed zeropages when calculating KSM profit Date: Wed, 24 May 2023 13:58:51 +0800 Message-Id: <20230524055851.20565-1-yang.yang29@zte.com.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <202305241351365661923@zte.com.cn> References: <202305241351365661923@zte.com.cn> MIME-Version: 1.0 X-Spam-Status: No, score=3.4 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,FSL_HELO_NON_FQDN_1, HEADER_FROM_DIFFERENT_DOMAINS,HELO_NO_DOMAIN,NO_DNS_FOR_FROM, RCVD_IN_PBL,RDNS_NONE,SPF_SOFTFAIL,SPOOFED_FREEMAIL_NO_RDNS, T_SCC_BODY_TEXT_LINE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Level: *** X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1766754441785541402?= X-GMAIL-MSGID: =?utf-8?q?1766754441785541402?= From: xu xin When use_zero_pages is enabled, the calculation of ksm profit is not correct because ksm zero pages is not counted in. So update the calculation of KSM profit including the documentation. Signed-off-by: xu xin Cc: Xiaokai Ran Cc: Yang Yang Cc: Jiang Xuexin Cc: Claudio Imbrenda Cc: David Hildenbrand Acked-by: David Hildenbrand --- Documentation/admin-guide/mm/ksm.rst | 18 +++++++++++------- mm/ksm.c | 4 ++-- 2 files changed, 13 insertions(+), 9 deletions(-) diff --git a/Documentation/admin-guide/mm/ksm.rst b/Documentation/admin-guide/mm/ksm.rst index 6cc919dbfd55..5c5be7bd84b8 100644 --- a/Documentation/admin-guide/mm/ksm.rst +++ b/Documentation/admin-guide/mm/ksm.rst @@ -203,21 +203,25 @@ several times, which are unprofitable memory consumed. 1) How to determine whether KSM save memory or consume memory in system-wide range? Here is a simple approximate calculation for reference:: - general_profit =~ pages_sharing * sizeof(page) - (all_rmap_items) * + general_profit =~ ksm_saved_pages * sizeof(page) - (all_rmap_items) * sizeof(rmap_item); - where all_rmap_items can be easily obtained by summing ``pages_sharing``, - ``pages_shared``, ``pages_unshared`` and ``pages_volatile``. + where ksm_saved_pages equals to the sum of ``pages_sharing`` + + ``ksm_zero_pages`` of the system, and all_rmap_items can be easily + obtained by summing ``pages_sharing``, ``pages_shared``, ``pages_unshared`` + and ``pages_volatile``. 2) The KSM profit inner a single process can be similarly obtained by the following approximate calculation:: - process_profit =~ ksm_merging_pages * sizeof(page) - + process_profit =~ ksm_saved_pages * sizeof(page) - ksm_rmap_items * sizeof(rmap_item). - where ksm_merging_pages is shown under the directory ``/proc//``, - and ksm_rmap_items is shown in ``/proc//ksm_stat``. The process profit - is also shown in ``/proc//ksm_stat`` as ksm_process_profit. + where ksm_saved_pages equals to the sum of ``ksm_merging_pages`` and + ``ksm_zero_pages``, both of which are shown under the directory + ``/proc//ksm_stat``, and ksm_rmap_items is also shown in + ``/proc//ksm_stat``. The process profit is also shown in + ``/proc//ksm_stat`` as ksm_process_profit. From the perspective of application, a high ratio of ``ksm_rmap_items`` to ``ksm_merging_pages`` means a bad madvise-applied policy, so developers or diff --git a/mm/ksm.c b/mm/ksm.c index 07a6fe7d7c99..1c7d0e215c47 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -3090,7 +3090,7 @@ static void wait_while_offlining(void) #ifdef CONFIG_PROC_FS long ksm_process_profit(struct mm_struct *mm) { - return mm->ksm_merging_pages * PAGE_SIZE - + return (long)(mm->ksm_merging_pages + mm->ksm_zero_pages) * PAGE_SIZE - mm->ksm_rmap_items * sizeof(struct ksm_rmap_item); } #endif /* CONFIG_PROC_FS */ @@ -3371,7 +3371,7 @@ static ssize_t general_profit_show(struct kobject *kobj, { long general_profit; - general_profit = ksm_pages_sharing * PAGE_SIZE - + general_profit = (ksm_pages_sharing + ksm_zero_pages) * PAGE_SIZE - ksm_rmap_items * sizeof(struct ksm_rmap_item); return sysfs_emit(buf, "%ld\n", general_profit);