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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 258DDC46467 for ; Mon, 26 Dec 2022 02:06:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231500AbiLZCGK (ORCPT ); Sun, 25 Dec 2022 21:06:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229445AbiLZCGG (ORCPT ); Sun, 25 Dec 2022 21:06:06 -0500 Received: from mxct.zte.com.cn (mxct.zte.com.cn [183.62.165.209]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D7D5DC8 for ; Sun, 25 Dec 2022 18:06:05 -0800 (PST) Received: from mse-fl1.zte.com.cn (unknown [10.5.228.132]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mxct.zte.com.cn (FangMail) with ESMTPS id 4NgLjl6hXqz4xpyB; Mon, 26 Dec 2022 10:06:03 +0800 (CST) Received: from szxlzmapp03.zte.com.cn ([10.5.231.207]) by mse-fl1.zte.com.cn with SMTP id 2BQ25poD056061; Mon, 26 Dec 2022 10:05:51 +0800 (+08) (envelope-from yang.yang29@zte.com.cn) Received: from mapi (szxlzmapp01[null]) by mapi (Zmail) with MAPI id mid14; Mon, 26 Dec 2022 10:05:52 +0800 (CST) Date: Mon, 26 Dec 2022 10:05:52 +0800 (CST) X-Zmail-TransId: 2b0363a90180ffffffff8da76b70 X-Mailer: Zmail v1.0 Message-ID: <202212261005526160207@zte.com.cn> Mime-Version: 1.0 From: To: Cc: , , , , , , , , Subject: =?UTF-8?B?W1BBVENIIHY0IDQvNl0ga3NtOiBjb3VudCB6ZXJvIHBhZ2VzIGZvciBlYWNoIHByb2Nlc3M=?= Content-Type: text/plain; charset="UTF-8" X-MAIL: mse-fl1.zte.com.cn 2BQ25poD056061 X-Fangmail-Gw-Spam-Type: 0 X-FangMail-Miltered: at cgslv5.04-192.168.251.13.novalocal with ID 63A9018B.002 by FangMail milter! X-FangMail-Envelope: 1672020363/4NgLjl6hXqz4xpyB/63A9018B.002/10.5.228.132/[10.5.228.132]/mse-fl1.zte.com.cn/ X-Fangmail-Anti-Spam-Filtered: true X-Fangmail-MID-QID: 63A9018B.002/4NgLjl6hXqz4xpyB Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: xu xin As the number of ksm zero pages is not included in ksm_merging_pages per process when enabling use_zero_pages, it's unclear of how many actual pages are merged by KSM. To let users accurately estimate their memory demands when unsharing KSM zero-pages, it's necessary to show KSM zero- pages per process. since unsharing zero pages placed by KSM accurately is achieved, then tracking empty pages merging and unmerging is not a difficult thing any longer. Since we already have /proc//ksm_stat, just add the information of zero_pages_sharing in it. Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Xuexin Jiang Cc: Xiaokai Ran Cc: Yang Yang Signed-off-by: xu xin --- fs/proc/base.c | 1 + include/linux/mm_types.h | 7 ++++++- mm/ksm.c | 2 ++ 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 9e479d7d202b..ac9ebe972be0 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3207,6 +3207,7 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, mm = get_task_mm(task); if (mm) { seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items); + seq_printf(m, "zero_pages_sharing %lu\n", mm->ksm_zero_pages_sharing); mmput(mm); } diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3b8475007734..9081cfe89d6f 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -776,7 +776,7 @@ struct mm_struct { #ifdef CONFIG_KSM /* * Represent how many pages of this process are involved in KSM - * merging. + * merging (not including ksm_zero_pages_sharing). */ unsigned long ksm_merging_pages; /* @@ -784,6 +784,11 @@ struct mm_struct { * including merged and not merged. */ unsigned long ksm_rmap_items; + /* + * Represent how many empty pages are merged with kernel zero + * pages when enabling KSM use_zero_pages. + */ + unsigned long ksm_zero_pages_sharing; #endif #ifdef CONFIG_LRU_GEN struct { diff --git a/mm/ksm.c b/mm/ksm.c index e02cc89512cd..6eb85de7b69f 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -794,6 +794,7 @@ static inline void clean_rmap_item_zero_flag(struct ksm_rmap_item *rmap_item) { if (rmap_item->address & ZERO_PAGE_FLAG) { ksm_zero_pages_sharing--; + rmap_item->mm->ksm_zero_pages_sharing--; rmap_item->address &= PAGE_MASK; } } @@ -2117,6 +2118,7 @@ static int try_to_merge_with_kernel_zero_page(struct ksm_rmap_item *rmap_item, if (!err) { rmap_item->address |= ZERO_PAGE_FLAG; ksm_zero_pages_sharing++; + rmap_item->mm->ksm_zero_pages_sharing++; } } else { /* If the vma is out of date, we do not need to continue. */ -- 2.15.2