From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 D14403EEAC2 for ; Sat, 12 Sep 2026 07:25:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789197904; cv=none; b=jHUVPL9l5q/dxxgAs06aUZStoFYO1C3qLa0ma5a4/jlYGs9tWnAX9qNdynTof2sPA56YMI9cDDyPyRB8uw+bpLFeXP1mBlEmf3xO26zI3r93PxrcSBRvgwQebN9HUN4miNcMtDy0IJRiD+Xgbcm+hY0X3/HfU6KISwkPFcFW8i8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789197904; c=relaxed/simple; bh=0RagBpzPZglqoXHVeJKaGBp4mZInDgI9Ggov4Okvw/o=; h=Date:To:From:Subject:Message-Id; b=XU9tgJn+AcDgb5oKGhbcWicxBImGBkjgxKop6rqBx9v4FdOzGMGmNePYrvi/EB9lLMiKi+2xYgTBq99bxvnP2YpFtY09CkR4MRqkgw/Y3qrmyHJQ7XFtVD+G8XTfnjBldaXh65XVAtW0Lwafe18YQXA0XzZ4Bse6hS8BrUA7q/s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=ekW7qK59; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="ekW7qK59" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D5761F000FF; Sat, 12 Sep 2026 07:25:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789197902; bh=DTksGSNlJkSt1Pw6jnkpffnEmWBXt7XrkA4qPypR9ME=; h=Date:To:From:Subject; b=ekW7qK59Q9hbnOEbDjkhCHtFTSWkngboO/voNJdHbZUFpwBiVl9iCuC8j+mQwUPzo iMck7sDSFv1SAHqY07BQ2D1WYmox+3D+XzCUSf4c6yNG00Po4/kwES2j8RdHqe+Ka1 l+InCr19GSRdj1t5eb2yWZ3MXznDKiLlsd/qGbjI= Date: Sat, 12 Sep 2026 00:25:02 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,vbabka@kernel.org,usama.arif@linux.dev,pfalcato@suse.de,paulmck@kernel.org,ljs@kernel.org,liam@infradead.org,jannh@google.com,david@kernel.org,surenb@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: + proc-task_mmu-remove-special-casing-of-smap_gather_stats-start-parameter.patch added to mm-new branch Message-Id: <20260912072502.7D5761F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: proc/task_mmu: remove special-casing of smap_gather_stats() start parameter has been added to the -mm mm-new branch. Its filename is proc-task_mmu-remove-special-casing-of-smap_gather_stats-start-parameter.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/proc-task_mmu-remove-special-casing-of-smap_gather_stats-start-parameter.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Suren Baghdasaryan Subject: proc/task_mmu: remove special-casing of smap_gather_stats() start parameter Date: Fri, 11 Sep 2026 12:41:42 -0700 smap_gather_stats() interprets its start parameter to mean vma->vm_start when it's set to 0. Eliminate this special interpretation and provide two separate functions for a partial and complete VMA walk. 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. Link: https://lore.kernel.org/20260911194145.1781926-5-surenb@google.com Signed-off-by: Suren Baghdasaryan Signed-off-by: Andrew Morton Suggested by: Lorenzo Stoakes Reviewed-by: Lorenzo Stoakes (ARM) Cc: David Hildenbrand (Arm) Cc: Jann Horn Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: "Paul E . McKenney" Cc: Pedro Falcato Cc: Usama Arif Cc: Vlastimil Babka --- fs/proc/task_mmu.c | 52 ++++++++++++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 17 deletions(-) --- a/fs/proc/task_mmu.c~proc-task_mmu-remove-special-casing-of-smap_gather_stats-start-parameter +++ a/fs/proc/task_mmu.c @@ -1246,20 +1246,26 @@ get_smaps_shmem_walk_ops(struct proc_map 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_range() - Gather mem stats from a portion of the @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 portion of the VMA starting at the @start + * address. */ -static void smap_gather_stats(struct proc_maps_private *priv, - struct vm_area_struct *vma, - struct mem_size_stats *mss, unsigned long start) +static void smap_gather_stats_range(struct proc_maps_private *priv, + struct vm_area_struct *vma, + 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)) @@ -1278,20 +1284,31 @@ static void smap_gather_stats(struct pro const unsigned long shmem_swapped = shmem_swap_usage(vma); const bool is_cow = vma_is_cow_mapping(vma); - if (start || (shmem_swapped && is_cow)) + if (is_partial || (shmem_swapped && is_cow)) ops = get_smaps_shmem_walk_ops(priv); else mss->swap += shmem_swapped; } - 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); } +/** + * smap_gather_stats() - Gather mem stats from the entire @vma. + * @priv: proc maps private state. + * @vma: The VMA to gather stats for. + * @mss: The accumulated stats. + * + * This gathers stats for the whole of the VMA. + */ +static void smap_gather_stats(struct proc_maps_private *priv, + struct vm_area_struct *vma, struct mem_size_stats *mss) +{ + smap_gather_stats_range(priv, vma, mss, vma->vm_start); +} + #define SEQ_PUT_DEC(str, val) \ seq_put_decimal_ull_width(m, str, (val) >> 10, 8) @@ -1342,7 +1359,7 @@ static int show_smap(struct seq_file *m, struct vm_area_struct *vma = v; struct mem_size_stats mss = {}; - smap_gather_stats(priv, vma, &mss, 0); + smap_gather_stats(priv, vma, &mss); show_map_vma(m, vma); @@ -1395,7 +1412,7 @@ static int show_smaps_rollup(struct seq_ vma_start = vma->vm_start; do { - smap_gather_stats(priv, vma, &mss, 0); + smap_gather_stats(priv, vma, &mss); last_vma_end = vma->vm_end; /* @@ -1454,14 +1471,15 @@ static int show_smaps_rollup(struct seq_ /* 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); last_vma_end = vma->vm_end; continue; } /* Case 4 above */ if (vma->vm_end > last_vma_end) { - smap_gather_stats(priv, vma, &mss, last_vma_end); + smap_gather_stats_range(priv, vma, &mss, + last_vma_end); last_vma_end = vma->vm_end; } } _ Patches currently in -mm which might be from surenb@google.com are proc-task_mmu-remove-unnecessary-helpers.patch proc-task_mmu-remove-unnecessary-inlines-in-function-definitions.patch proc-task_mmu-clarify-shmem-mapping-walk-conditions-in-smap_gather_stats.patch proc-task_mmu-remove-special-casing-of-smap_gather_stats-start-parameter.patch proc-task_mmu-change-proc_get_vma-to-stop-returning-gate-vma-at-the-end.patch proc-task_mmu-read-proc-pid-smaps_rollup-under-per-vma-lock.patch selftests-proc-add-proc-pid-smaps_rollup-tearing-tests.patch