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 4A13E39FCCC; Fri, 10 Jul 2026 20:27:34 +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=1783715255; cv=none; b=rBQCAQ7q3IrcR5X2d4t3IRgn6mluKo2WkGfYz8/15plyT7yDDEK4izOR9dHFKUcFjJDVT8FwyJH+e9TEIaGRpi+HCNjIrKtBovnFiy2PTvUU5g83EFhZkbb6pxrUXIA1LIH9KV/gNz4L1LZJmKBrMjU1zUNZghTpaQEzW2A9k1s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783715255; c=relaxed/simple; bh=0LxPiqBxAD9IhreoUXWjHFUoHlm6qZINpaBU8bU6qMA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=X7+IPacAPY3Afs81nmiFdEKViUW2dBpXUwkdRQANrSW30YB8oqYnEARVuVP/Aql6akPGKkzX9ROPKwU1Ej7ZAhTaI6FZlqCIyC+vchhOZV27o3wme2x6prCxlmggSfB8G7zkk4Ewfvon+njpGdtvEepQrbVy8Uv2tO8rc43H7U0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JBGjC0JG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JBGjC0JG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 534F11F000E9; Fri, 10 Jul 2026 20:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783715254; bh=nwHLf7niWPUb+EByGfZPa1IGezWCh6hKiz5/kPjeOK4=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=JBGjC0JG6taRh6W76fZOLNsjNinAKtLEZdyZf56hkpmD1SsPyspbJgP79fA97RNFu rInXrcVoyDKxluHVIscUJlMQmCqhyn5vwU71G1ydzkj06R3KS8xqkqBGEHAwFFX5/0 oLU/CAkX/h1Gzz1GS/ZeKTBmtJF2fpl8ljFKwZRglGHj0rtfQ8ndwlo5G5KRsMycDE nxh7CmmMG6beLYOuSIkOMMaLZ1yeaXbdG7b7alCjP4UkqQg8wtUK6yOWoFCJZKQTpC o0a+qybijiTRUl268p65PJiHOM6drgF6XspLNQuwd7bBhft3/7HTnnjHqcGpREBH1/ t6TG2qcQpKTOw== From: Lorenzo Stoakes Date: Fri, 10 Jul 2026 21:17:07 +0100 Subject: [PATCH v2 26/33] mm/vma: update vma_shrink() to not pass start, pgoff parameters Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260710-b4-pre-scalable-cow-v2-26-2a5aa403d977@kernel.org> References: <20260710-b4-pre-scalable-cow-v2-0-2a5aa403d977@kernel.org> In-Reply-To: <20260710-b4-pre-scalable-cow-v2-0-2a5aa403d977@kernel.org> To: Andrew Morton , David Hildenbrand , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Rik van Riel , Harry Yoo , Jann Horn , Lance Yang , Pedro Falcato , Russell King , Dinh Nguyen , Simon Schuster , "James E.J. Bottomley" , Helge Deller , Alexander Viro , Christian Brauner , Jan Kara , Dan Williams , Matthew Wilcox , Muchun Song , Oscar Salvador , Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , James Clark , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Miaohe Lin , Naoya Horiguchi , Xu Xin , Chengming Zhou , SJ Park , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Hugh Dickins , Peter Xu , Kees Cook , Marek Szyprowski , Robin Murphy , Andrey Konovalov , Alexander Potapenko , Dmitry Vyukov , Steven Rostedt , Mathieu Desnoyers , Jarkko Sakkinen , Dave Hansen , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , Ian Abbott , H Hartley Sweeten , Lucas Stach , Christian Gmeiner , David Airlie , Simona Vetter , Patrik Jakobsson , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Rob Clark , Dmitry Baryshkov , Abhinav Kumar , Jessica Zhang , Sean Paul , Marijn Suijten , Tomi Valkeinen , Thierry Reding , Mikko Perttunen , Jonathan Hunter , Christian Koenig , Huang Rui , Matthew Auld , Jason Gunthorpe , Yishai Hadas , Shameer Kolothum , Kevin Tian , Ankit Agrawal , Alex Williamson , Paolo Bonzini , Shakeel Butt , Usama Arif Cc: Lorenzo Stoakes , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-fsdevel@vger.kernel.org, nvdimm@lists.linux.dev, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, damon@lists.linux.dev, iommu@lists.linux.dev, kasan-dev@googlegroups.com, linux-sgx@vger.kernel.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, linux-tegra@vger.kernel.org, kvm@vger.kernel.org, Russell King X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=4413; i=ljs@kernel.org; h=from:subject:message-id; bh=0LxPiqBxAD9IhreoUXWjHFUoHlm6qZINpaBU8bU6qMA=; b=owGbwMvMwCV2fu7ZrsZH9SKMp9WSGLICg23LjgYW8Qj8SmXmjwgOjpPi2iF7zC5wcn+95fs7l iaOVf86SlkYxLgYZMUUWZ5/Ed8fJBI2r/OCvxvMHFYmkCEMXJwCMBFxP0aGV36b2hPsZB4I79HY so+HedmSLrH9my+69IdZeCZd5ouYx8iwVvT+y+n/804y/Dn3tjAuJ/T0sU1CtjziL09p1mW378z nAAA= X-Developer-Key: i=ljs@kernel.org; a=openpgp; fpr=E7F417BF5214569E89D04F46CF9DCD8A81E27F14 vma_shrink() is only used by relocate_vma_down() to shrink the tail of a VMA. Therefore neither the start nor the pgoff parameters make any sense. It seemed we were passing the pgoff parameter solely to satisfy vma_set_range()'s requirement for pgoff being specified. Since vma_set_range() is now isolated to vma.c, we can simply introduce __vma_set_range() which sets only vma->vm_[start, end], and invoke this instead, removing start and pgoff from vma_shrink() altogether. No functional change intended. Reviewed-by: Pedro Falcato Signed-off-by: Lorenzo Stoakes --- mm/vma.c | 31 +++++++++++++++++-------------- mm/vma.h | 3 +-- mm/vma_exec.c | 2 +- tools/testing/vma/tests/merge.c | 2 +- 4 files changed, 20 insertions(+), 18 deletions(-) diff --git a/mm/vma.c b/mm/vma.c index cc0e449ad0be..a474920a25b3 100644 --- a/mm/vma.c +++ b/mm/vma.c @@ -70,11 +70,17 @@ struct mmap_state { .state = VMA_MERGE_START, \ } -static void vma_set_range(struct vm_area_struct *vma, unsigned long start, - unsigned long end, pgoff_t pgoff) +static void __vma_set_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end) { vma->vm_start = start; vma->vm_end = end; +} + +static void vma_set_range(struct vm_area_struct *vma, unsigned long start, + unsigned long end, pgoff_t pgoff) +{ + __vma_set_range(vma, start, end); vma->vm_pgoff = pgoff; } @@ -1279,27 +1285,24 @@ int vma_expand(struct vma_merge_struct *vmg) return -ENOMEM; } -/* - * vma_shrink() - Reduce an existing VMAs memory area +/** + * vma_shrink() - Shrink the end of a VMA * @vmi: The vma iterator * @vma: The VMA to modify - * @start: The new start * @end: The new end * + * Note that the caller may only shrink the end of the VMA. + * * Returns: 0 on success, -ENOMEM otherwise */ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, - unsigned long start, unsigned long end, pgoff_t pgoff) + unsigned long end) { struct vma_prepare vp; - WARN_ON((vma->vm_start != start) && (vma->vm_end != end)); - - if (vma->vm_start < start) - vma_iter_config(vmi, vma->vm_start, start); - else - vma_iter_config(vmi, end, vma->vm_end); + VM_WARN_ON_ONCE(end > vma->vm_end); + vma_iter_config(vmi, end, vma->vm_end); if (vma_iter_prealloc(vmi, NULL)) return -ENOMEM; @@ -1307,10 +1310,10 @@ int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma, init_vma_prep(&vp, vma); vma_prepare(&vp); - vma_adjust_trans_huge(vma, start, end, NULL); + vma_adjust_trans_huge(vma, vma->vm_start, end, NULL); vma_iter_clear(vmi); - vma_set_range(vma, start, end, pgoff); + __vma_set_range(vma, vma->vm_start, end); vma_complete(&vp, vmi, vma->vm_mm); validate_mm(vma->vm_mm); return 0; diff --git a/mm/vma.h b/mm/vma.h index 14f026bf3be4..40effaa3ebe4 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -297,8 +297,7 @@ void validate_mm(struct mm_struct *mm); __must_check int vma_expand(struct vma_merge_struct *vmg); __must_check int vma_shrink(struct vma_iterator *vmi, - struct vm_area_struct *vma, - unsigned long start, unsigned long end, pgoff_t pgoff); + struct vm_area_struct *vma, unsigned long end); static inline int vma_iter_store_gfp(struct vma_iterator *vmi, struct vm_area_struct *vma, gfp_t gfp) diff --git a/mm/vma_exec.c b/mm/vma_exec.c index e3644a3042e2..13a05e041195 100644 --- a/mm/vma_exec.c +++ b/mm/vma_exec.c @@ -89,7 +89,7 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift) vma_prev(&vmi); /* Shrink the vma to just the new range */ - return vma_shrink(&vmi, vma, new_start, new_end, vma_start_pgoff(vma)); + return vma_shrink(&vmi, vma, new_end); } /* diff --git a/tools/testing/vma/tests/merge.c b/tools/testing/vma/tests/merge.c index f8666a755749..e357accc8499 100644 --- a/tools/testing/vma/tests/merge.c +++ b/tools/testing/vma/tests/merge.c @@ -227,7 +227,7 @@ static bool test_simple_shrink(void) ASSERT_FALSE(attach_vma(&mm, vma)); - ASSERT_FALSE(vma_shrink(&vmi, vma, 0, 0x1000, 0)); + ASSERT_FALSE(vma_shrink(&vmi, vma, 0x1000)); ASSERT_EQ(vma->vm_start, 0); ASSERT_EQ(vma->vm_end, 0x1000); -- 2.55.0