From patchwork Tue Dec 3 11:26:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: xu.xin16@zte.com.cn X-Patchwork-Id: 13892246 Received: from mxhk.zte.com.cn (mxhk.zte.com.cn [63.216.63.40]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 394CB2E3EE; Tue, 3 Dec 2024 11:26:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=63.216.63.40 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733225208; cv=none; b=gKVJjIZUnJuLhKGb4fXR2C/2xmPSztkyTnHwi3d3q9ZyXF+K2TQAS6lv0zI48ZSWNJe+wp4x+aX9FSVusoMO9FTOxLrxSVF5TxJ/r5Uu1ywAuP9nerf126OthoAanLB5oy27oHPlMn4NV3h2LeEdd0do0+8LPcTL+MxB/qg1i/I= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733225208; c=relaxed/simple; bh=v2cCA4SkHBFossPNjsuI3dIhlyDjd2P1Q/6P1WUpY1M=; h=Date:Message-ID:Mime-Version:From:To:Cc:Subject:Content-Type; b=IREnG6PUEKZVF/kRnY+uIw20aNd0ANk4tx2pWh9/No4f82kUDR7VVgRc5Ri4QmRl2rXCrdx6jFCMxOnSFru6pgmeX6H9Jy3/KmagOUj2wiJM069uoUUD/qwgnE/uiTiBD7SkqNO1ysQcH3uPI17Lt+KcNeRuklMe44cSz4K2fSM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zte.com.cn; spf=pass smtp.mailfrom=zte.com.cn; arc=none smtp.client-ip=63.216.63.40 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zte.com.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zte.com.cn Received: from mse-fl2.zte.com.cn (unknown [10.5.228.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mxhk.zte.com.cn (FangMail) with ESMTPS id 4Y2ddp0qMKz8R040; Tue, 3 Dec 2024 19:26:38 +0800 (CST) Received: from xaxapp01.zte.com.cn ([10.88.99.176]) by mse-fl2.zte.com.cn with SMTP id 4B3BQUho000945; Tue, 3 Dec 2024 19:26:31 +0800 (+08) (envelope-from xu.xin16@zte.com.cn) Received: from mapi (xaxapp04[null]) by mapi (Zmail) with MAPI id mid32; Tue, 3 Dec 2024 19:26:33 +0800 (CST) Date: Tue, 3 Dec 2024 19:26:33 +0800 (CST) X-Zmail-TransId: 2afb674eeae972d-c1081 X-Mailer: Zmail v1.0 Message-ID: <20241203192633836RVHhkoK1Amnqjt84D4Ryd@zte.com.cn> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 From: To: , Cc: , , , Subject: =?utf-8?q?=5BPATCH_linux-next_v4=5D_ksm=3A_add_ksm_involvement_info?= =?utf-8?q?rmation_for_each_process?= X-MAIL: mse-fl2.zte.com.cn 4B3BQUho000945 X-Fangmail-Anti-Spam-Filtered: true X-Fangmail-MID-QID: 674EEAEE.000/4Y2ddp0qMKz8R040 From: xu xin In /proc//ksm_stat, Add two extra ksm involvement items including KSM_mergeable and KSM_merge_any. It helps administrators to better know the system's KSM behavior at process level. KSM_mergeable: yes/no whether any VMAs of the process'mm are currently applicable to KSM. KSM_merge_any: yes/no whether the process'mm is added by prctl() into the candidate list of KSM or not, and fully enabled at process level. Changelog ========= v3 -> v4: 1. Keep the name of ksm items consistent in /proc/pid/ksm_stat. * KSM_mergeable -> ksm_mergeable * KSM_merge_any -> ksm_merge_any 2. Hold the read lock of mmap while calling ksm_process_mergeable() Suggested-by: https://lore.kernel.org/all/cec0ed06-b5d0-45aa-ad2b-eaca6dd7bacb@redhat.com/ v2 -> v3: Update the KSM_mergeable getting method: loop up if any vma is mergeable to KSM. https://lore.kernel.org/all/bc0e1cdd-2d9d-437c-8fc9-4df0e13c48c0@redhat.com/ v1 -> v2: replace the internal flag names with straightforward strings. * MMF_VM_MERGEABLE -> KSM_mergeable * MMF_VM_MERGE_ANY -> KSM_merge_any Signed-off-by: xu xin Cc: Wang Yaxin --- fs/proc/base.c | 11 +++++++++++ include/linux/ksm.h | 1 + mm/ksm.c | 19 +++++++++++++++++++ 3 files changed, 31 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index 0edf14a9840e..a50b222a5917 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3269,6 +3269,7 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, struct pid *pid, struct task_struct *task) { struct mm_struct *mm; + int ret = 0; mm = get_task_mm(task); if (mm) { @@ -3276,6 +3277,16 @@ static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns, seq_printf(m, "ksm_zero_pages %ld\n", mm_ksm_zero_pages(mm)); seq_printf(m, "ksm_merging_pages %lu\n", mm->ksm_merging_pages); seq_printf(m, "ksm_process_profit %ld\n", ksm_process_profit(mm)); + seq_printf(m, "ksm_merge_any: %s\n", + test_bit(MMF_VM_MERGE_ANY, &mm->flags) ? "yes" : "no"); + ret = mmap_read_lock_killable(mm); + if (ret) { + mmput(mm); + return ret; + } + seq_printf(m, "ksm_mergeable: %s\n", + ksm_process_mergeable(mm) ? "yes" : "no"); + mmap_read_unlock(mm); mmput(mm); } diff --git a/include/linux/ksm.h b/include/linux/ksm.h index 6a53ac4885bb..d73095b5cd96 100644 --- a/include/linux/ksm.h +++ b/include/linux/ksm.h @@ -93,6 +93,7 @@ void folio_migrate_ksm(struct folio *newfolio, struct folio *folio); void collect_procs_ksm(const struct folio *folio, const struct page *page, struct list_head *to_kill, int force_early); long ksm_process_profit(struct mm_struct *); +bool ksm_process_mergeable(struct mm_struct *mm); #else /* !CONFIG_KSM */ diff --git a/mm/ksm.c b/mm/ksm.c index 7ac59cde626c..e87af149d5ee 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -3263,6 +3263,25 @@ static void wait_while_offlining(void) #endif /* CONFIG_MEMORY_HOTREMOVE */ #ifdef CONFIG_PROC_FS +/* + * The process is mergeable only if any VMA (and which) is currently + * applicable to KSM. + * + * The mmap lock must be held in read mode. + */ +bool ksm_process_mergeable(struct mm_struct *mm) +{ + struct vm_area_struct *vma; + + mmap_assert_locked(mm); + VMA_ITERATOR(vmi, mm, 0); + for_each_vma(vmi, vma) + if (vma->vm_flags & VM_MERGEABLE) + return true; + + return false; +} + long ksm_process_profit(struct mm_struct *mm) { return (long)(mm->ksm_merging_pages + mm_ksm_zero_pages(mm)) * PAGE_SIZE -