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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3EAF8C79FAA for ; Mon, 7 Sep 2026 06:39:39 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 556626B00A5; Mon, 7 Sep 2026 02:39:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 507B56B00A6; Mon, 7 Sep 2026 02:39:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41E4F6B00A7; Mon, 7 Sep 2026 02:39:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 07FE76B00A5 for ; Mon, 7 Sep 2026 02:39:32 -0400 (EDT) Received: from smtpin25.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 682C4C066C for ; Mon, 7 Sep 2026 06:39:31 +0000 (UTC) X-FDA: 85186014942.25.875067A Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by imf17.hostedemail.com (Postfix) with ESMTP id A37EC40002 for ; Mon, 7 Sep 2026 06:39:29 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20251104 header.b=KWaf66Jv; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf17.hostedemail.com: domain of 3IFyeagYKCK0fheRaOTbbTYR.PbZYVahk-ZZXiNPX.beT@flex--surenb.bounces.google.com designates 209.85.216.71 as permitted sender) smtp.mailfrom=3IFyeagYKCK0fheRaOTbbTYR.PbZYVahk-ZZXiNPX.beT@flex--surenb.bounces.google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1788763169; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=l82YwPFJoqBct/wpgBVxgb9B5/Qm0auI8Z1CtPsM/dw=; b=dLudYTJPnK68BpIao54nVpGcBw7ZSKxcTMWvvfT7iNFimVQf+y32OzbTcSkHvNEMQS2czb WQXi6gimD5iiLkIh0TWKPctagax049Db+PhPOPj+FEHMplRGWcw+WDxg4VwNPBUzKG2EbH /J/3OgMU/NxFoi4xZfLzuKrVrpxkI+U= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20251104 header.b=KWaf66Jv; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf17.hostedemail.com: domain of 3IFyeagYKCK0fheRaOTbbTYR.PbZYVahk-ZZXiNPX.beT@flex--surenb.bounces.google.com designates 209.85.216.71 as permitted sender) smtp.mailfrom=3IFyeagYKCK0fheRaOTbbTYR.PbZYVahk-ZZXiNPX.beT@flex--surenb.bounces.google.com ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1788763169; b=eKWNXoHs0CJcSvZ2WuC9C7113/OmNlvh7J7UHdqdFUt+mWxGTsoJJS8ZQgXJV5h7U6BdP/ tYrOxPkDPGZwn17qSOPAoTGoKvVjYVxbTQvNKJ387lUrog+COSwSnqL0pkSQ7GB5KcYBmR 8W9SXJ31QrHdQt4Sks/5CmEX8bt11o4= Received: by mail-pj1-f71.google.com with SMTP id 98e67ed59e1d1-398fe469aa0so5291543a91.2 for ; Sun, 06 Sep 2026 23:39:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788763168; x=1789367968; darn=kvack.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=l82YwPFJoqBct/wpgBVxgb9B5/Qm0auI8Z1CtPsM/dw=; b=KWaf66JvmTbbTFbFrx8Zhe/wtBsEF56Q9Qu4qsp6dS25NgmNYswOUc0pI0kNycphtN fOxZGhyb++gEeg5r7/srXRyoMgT/bq5vL7s40462C1Z2X2KnrkaX25GryhlLI4OX+HHZ P/SXfjwIDAHK1E8YDa6uOLaEBzOyLR/zWxV2O6haxSkmuTS9P3GHukMgHpr+cwBDVPnT fpudsxuqQO8FNL9zXk3x+krDof2tSeqvU9+mgGdHOL3AvdX6nzRxEA5qh/0UyXEGF2yl qJT/Ya7sX3vzgN9+iJDQAhlrCcw9pos3KF4fiNQ/0wKnFzwZ2ytVXyR4Vx84bDdDCVlb LHRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788763168; x=1789367968; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=l82YwPFJoqBct/wpgBVxgb9B5/Qm0auI8Z1CtPsM/dw=; b=GjMKmcJc1t/KaQVr3O1V1RvwNHYH0sxLk7S59b07S/LhiH/YpKo6ySNIjFSwpcj5c2 GD1RsxBiQHKMrpnRfZHCYSFyDxC1lil/tadd87fdN3TKQ/c6qMM2cRcmBNM3gKHMDxFL JrHJZvllTpOs4p64QAPsGkglGe3VA1YZKM17gpDQ6x+GceEfq+9KagQdIqqbeCum7giT 0PpWPx/94o0ICwlt8HwPWFC90VD6malWBDWhYJvofj2pCLL+DTv5toP4xovjVgmzsG/i LENPZyrKbTitWwqHYCk2NguNxA4ffPGS/Gq8e1AtHab/LTXxvv8e1PZbrVHiLKL+1uGB PlYQ== X-Forwarded-Encrypted: i=1; AKwUvBxjeAoHsqouxHeZ0zqFml/1MQojQcjbbteZNwm1/oFk6dFBUkNzZXpWbF4cO7nmrJSxKusG5aok0g==@kvack.org X-Gm-Message-State: AFuF++mrhos5N5rVHC99MNe+Ok3TCT34pCrqrlgRH/x1JDaPME7SJ4wK IvADzNvvnjjyWBFCYyNblSl2LvGwm2pHoCh30R0JvXQCeuzBp0K4BvahxU0qIz2qzmJC6F8mK6w ZdUobwg== X-Received: from dyjo27.prod.google.com ([2002:a05:7300:339b:b0:327:c2c1:f06f]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:5866:b0:398:e73e:5a13 with SMTP id 98e67ed59e1d1-39b2613272amr31362696a91.9.1788763168352; Sun, 06 Sep 2026 23:39:28 -0700 (PDT) Date: Sun, 6 Sep 2026 23:39:16 -0700 In-Reply-To: <20260907063918.3432401-1-surenb@google.com> Mime-Version: 1.0 References: <20260907063918.3432401-1-surenb@google.com> X-Mailer: git-send-email 2.55.0.979.g7e5102b832-goog Message-ID: <20260907063918.3432401-4-surenb@google.com> Subject: [PATCH v2 3/5] proc/task_mmu: remove special-casing of smap_gather_stats() start parameter From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: liam@infradead.org, ljs@kernel.org, vbabka@kernel.org, david@redhat.com, willy@infradead.org, jannh@google.com, paulmck@kernel.org, pfalcato@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, surenb@google.com Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: mygzgk711oa3tdhfhbxukt83b7g19iko X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: A37EC40002 X-Rspam-User: X-HE-Tag: 1788763169-915709 X-HE-Meta: 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 zkHWFfRZ 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: smap_gather_stats() interprets its start parameter to mean vma->vm_start when it's set to 0. Eliminate this special interpretation and pass vma->vm_start explicitly when needed. Since smap_gather_stats() operates within a single VMA, we can replace walk_page_vma()/walk_page_range() calls with walk_page_range_vma() which is simpler and also can be called while holding per-VMA lock. No functional change intended. Suggested by: Lorenzo Stoakes Signed-off-by: Suren Baghdasaryan --- fs/proc/task_mmu.c | 40 ++++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 9908ba32f180..3351decd1172 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1246,20 +1246,27 @@ get_smaps_shmem_walk_ops(struct proc_maps_private *priv) return &smaps_shmem_walk_vma_lock_ops; } -/* - * Gather mem stats from @vma with the indicated beginning - * address @start, and keep them in @mss. +/** + * smap_gather_stats() - Gather mem stats from @vma. + * @priv: proc maps private state. + * @vma: The VMA to gather stats for. + * @mss: The accumulated stats. + * @start: The address from which to start. * - * Use vm_start of @vma as the beginning address if @start is 0. + * This gathers stats for the whole of the VMA unless the lock was dropped + * and VMA grew or got merged and we found it again, in which case we only + * gather stats for the remainder of the VMA range. */ static void smap_gather_stats(struct proc_maps_private *priv, struct vm_area_struct *vma, - struct mem_size_stats *mss, unsigned long start) + struct mem_size_stats *mss, + unsigned long start) { const struct mm_walk_ops *ops = get_smaps_walk_ops(priv); + const bool is_partial = start > vma->vm_start; /* Invalid start */ - if (start >= vma->vm_end) + if (start < vma->vm_start || start >= vma->vm_end) return; if (vma == get_gate_vma(priv->lock_ctx.mm)) @@ -1279,20 +1286,17 @@ static void smap_gather_stats(struct proc_maps_private *priv, * Unless we know that the shmem object (or the part mapped by * our VMA) has no swapped out pages at all. */ - unsigned long shmem_swapped = shmem_swap_usage(vma); + const unsigned long shmem_swapped = shmem_swap_usage(vma); + const bool shared_or_ro = vma_test(vma, VMA_SHARED_BIT) || + !vma_test(vma, VMA_WRITE_BIT); - if (!start && (!shmem_swapped || (vma->vm_flags & VM_SHARED) || - !(vma->vm_flags & VM_WRITE))) { + if (!is_partial && (!shmem_swapped || shared_or_ro)) mss->swap += shmem_swapped; - } else { + else ops = get_smaps_shmem_walk_ops(priv); - } } - if (!start) - walk_page_vma(vma, ops, mss); - else - walk_page_range(vma->vm_mm, start, vma->vm_end, ops, mss); + walk_page_range_vma(vma, start, vma->vm_end, ops, mss); reacquire_rcu(priv); } @@ -1347,7 +1351,7 @@ static int show_smap(struct seq_file *m, void *v) struct vm_area_struct *vma = v; struct mem_size_stats mss = {}; - smap_gather_stats(priv, vma, &mss, 0); + smap_gather_stats(priv, vma, &mss, vma->vm_start); show_map_vma(m, vma); @@ -1400,7 +1404,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) vma_start = vma->vm_start; do { - smap_gather_stats(priv, vma, &mss, 0); + smap_gather_stats(priv, vma, &mss, vma->vm_start); last_vma_end = vma->vm_end; /* @@ -1459,7 +1463,7 @@ static int show_smaps_rollup(struct seq_file *m, void *v) /* Case 1 and 2 above */ if (vma->vm_start >= last_vma_end) { - smap_gather_stats(priv, vma, &mss, 0); + smap_gather_stats(priv, vma, &mss, vma->vm_start); last_vma_end = vma->vm_end; continue; } -- 2.55.0.979.g7e5102b832-goog