From patchwork Tue Jun 13 03:09:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Yang X-Patchwork-Id: 107052 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp274421vqr; Mon, 12 Jun 2023 20:16:04 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ4D522mF22J4Lr7bUJYpxQrupyB1iZvxlBlv/dr5sgcEoWt9NK5uFZ/VcrRT/69sxm4asIp X-Received: by 2002:a05:6402:47:b0:50b:c56c:43d0 with SMTP id f7-20020a056402004700b0050bc56c43d0mr7203065edu.1.1686626164381; Mon, 12 Jun 2023 20:16:04 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1686626164; cv=none; d=google.com; s=arc-20160816; b=BE45NtGc1PP4726CfeoffbVnAK7NjJfPLS5zTV8NE7V9TKMxALnchJXtoGV3cauF3k HG4k/pm8zDsuQfdtIscJ82k9ZpWgA4tGLypNFcmui8/6YL1GA53+NTrtKdR2jkwOMsxA p1GqbdOZK+sbFrJb+KIIe37JVjdlzcwjv8yVFqdWn7O8swd2kYOe/mO4vAjLkYWzBmfI VX2QVhq9tPqkIN0S6orfYKjQ5NZW57VoUfafIop9hVMsXrKVqBxRNHGI3cZa6yF+fbRm RkJaNg0DLA3xgwh7OeaJtxygKPMkk+DEW1AWaJPAQPvVlo42VAayMBQlpDvW2xD3cWXt cgwQ== 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=/IGz+EOJ6ZJOoVXa4iGXtocLRze/sO07dBQARymqz/w=; b=HFPEiBU/EgcFYuobJVrjPEgeG4IMAPJdI8BAMUXDspRLr7P+Ag0KbBuSQUxAHn0kl3 K9MZBJ0EJHyhY6A/W980wsB8a5hps6uXN55pk2kKTSrLVJ/olwfSlMW3VxF0e0DgkalQ Ccmm3npkZly6nPhh6mm81vQ7TgjeIVe1NHSB3gm4ZeeklqZAZ29qW/8GDiTa6oPKS09K GCotV48U2v1/P9iOq52AsXcb3mxPxdqV22p7xCQ+S9ijTdiCUEZWI2x89CkCdIznh1u4 MEyNOoCM02qRPaRVS4bnCP/5hjT9IuaBgvksMskG2IA9kQSwQUmrJHDkQmYaZ33QKPmK zXew== 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 dy19-20020a05640231f300b0050bc94fe05csi6937650edb.117.2023.06.12.20.15.41; Mon, 12 Jun 2023 20:16:04 -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 S231941AbjFMDLz (ORCPT + 99 others); Mon, 12 Jun 2023 23:11:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240443AbjFMDLJ (ORCPT ); Mon, 12 Jun 2023 23:11:09 -0400 Received: from ubuntu20 (unknown [193.203.214.57]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26AFEE7A for ; Mon, 12 Jun 2023 20:09:46 -0700 (PDT) Received: by ubuntu20 (Postfix, from userid 1003) id B01FFE22BE; Tue, 13 Jun 2023 11:09:44 +0800 (CST) From: Yang Yang To: akpm@linux-foundation.org, david@redhat.com Cc: yang.yang29@zte.com.cn, imbrenda@linux.ibm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ran.xiaokai@zte.com.cn, xu.xin.sc@gmail.com, xu.xin16@zte.com.cn, Jiang Xuexin Subject: [PATCH RESEND v10 4/5] ksm: consider KSM-placed zeropages when calculating KSM profit Date: Tue, 13 Jun 2023 11:09:42 +0800 Message-Id: <20230613030942.186041-1-yang.yang29@zte.com.cn> X-Mailer: git-send-email 2.25.1 In-Reply-To: <202306131104554703428@zte.com.cn> References: <202306131104554703428@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?1768555716948269050?= X-GMAIL-MSGID: =?utf-8?q?1768555716948269050?= 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 Acked-by: David Hildenbrand Cc: Xiaokai Ran Cc: Yang Yang Cc: Jiang Xuexin Cc: Claudio Imbrenda --- 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);