From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9BE1C189913 for ; Wed, 6 Nov 2024 01:01:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730854888; cv=none; b=rB8nt2HNV5dbUuuX1pa4B1BsW0GMetliiOL1T5Qg02NZpKtSo/zY19GZWvyLUT1IXUKCz2SEZMeK7EW4a2Nhp5hh6q7dxomJq0B/D/n8bUoJDn/dfQzSLz1BLbhhjyW/4SzBqzB2x45vLj5pJKtQ4H/ep1dHDM1LJJL3rsiBFzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730854888; c=relaxed/simple; bh=sQWXVlE17Xc7DsnZx8g3utPmTZc+fYAMrtC7kx+ZRQU=; h=Date:To:From:Subject:Message-Id; b=utCH7btEHol5fMV3PFaZtE/k4qRGCs9fS+2sVjC+RgHoTTKz8FwTzhCBQ9p7snPaVuynJUHatU1SPoTUrCATW+qmUBx5s83DugSAtc2hFsdh6qnkUe3V+5a2g3jUo1nfZGL6vx9OS0yuLqaijo1r/j6xoH+uzZJ3CRNiyTY0BQg= 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=1m7fHe8z; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="1m7fHe8z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 706D2C4CECF; Wed, 6 Nov 2024 01:01:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1730854888; bh=sQWXVlE17Xc7DsnZx8g3utPmTZc+fYAMrtC7kx+ZRQU=; h=Date:To:From:Subject:From; b=1m7fHe8zEI7aAY2RF1ZoCyqlr4iWg4V8XOFBAVIhhnf/dShnF2NmUwr1fCampVJm1 px2UwOoVHn2KJlsSrKQ6iaXgib9xfRjzTlHKO+MzyADy4tTEmv2Y3QGwQbbQWZzhjO ujAeR1plAGhE4qg+pCaaTpyd/av8D845BC8/yeJw= Date: Tue, 05 Nov 2024 17:01:27 -0800 To: mm-commits@vger.kernel.org,vbabka@suse.cz,lorenzo.stoakes@oracle.com,Liam.Howlett@oracle.com,jannh@google.com,richard.weiyang@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-vma-the-pgoff-is-correct-if-can_merge_right.patch removed from -mm tree Message-Id: <20241106010128.706D2C4CECF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/vma: the pgoff is correct if can_merge_right has been removed from the -mm tree. Its filename was mm-vma-the-pgoff-is-correct-if-can_merge_right.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Wei Yang Subject: mm/vma: the pgoff is correct if can_merge_right Date: Thu, 24 Oct 2024 09:33:47 +0000 By this point can_vma_merge_right() must have returned true, which implies can_vma_merge_before() also returned true, which already asserts that the pgoff is as expected for a merge with the following VMA, thus this assignment is redundant. Below is a more detail explanation. Current definition of can_vma_merge_right() is: static bool can_vma_merge_right(struct vma_merge_struct *vmg, bool can_merge_left) { if (!vmg->next || vmg->end != vmg->next->vm_start || !can_vma_merge_before(vmg)) return false; ... } And: static bool can_vma_merge_before(struct vma_merge_struct *vmg) { pgoff_t pglen = PHYS_PFN(vmg->end - vmg->start); ... if (vmg->next->vm_pgoff == vmg->pgoff + pglen) return true; ... } Which implies vmg->pgoff == vmg->next->vm_pgoff - pglen. None of these values are changed between the check and prior assignment, so this was an entirely redundant assignment. [akpm@linux-foundation.org: remove now-unused local] [lorenzo.stoakes@oracle.com: rephrase the changelog] Link: https://lkml.kernel.org/r/20241024093347.18057-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang Reviewed-by: Lorenzo Stoakes Cc: Jann Horn Cc: Vlastimil Babka Cc: Liam R. Howlett Signed-off-by: Andrew Morton --- mm/vma.c | 3 --- 1 file changed, 3 deletions(-) --- a/mm/vma.c~mm-vma-the-pgoff-is-correct-if-can_merge_right +++ a/mm/vma.c @@ -962,9 +962,7 @@ struct vm_area_struct *vma_merge_new_ran { struct vm_area_struct *prev = vmg->prev; struct vm_area_struct *next = vmg->next; - unsigned long start = vmg->start; unsigned long end = vmg->end; - pgoff_t pglen = PHYS_PFN(end - start); bool can_merge_left, can_merge_right; bool just_expand = vmg->merge_flags & VMG_FLAG_JUST_EXPAND; @@ -986,7 +984,6 @@ struct vm_area_struct *vma_merge_new_ran if (can_merge_right) { vmg->end = next->vm_end; vmg->vma = next; - vmg->pgoff = next->vm_pgoff - pglen; } /* If we can merge with the previous VMA, adjust vmg accordingly. */ _ Patches currently in -mm which might be from richard.weiyang@gmail.com are mm-mlock-set-the-correct-prev-on-failure.patch maple_tree-print-empty-for-an-empty-tree-on-mt_dump.patch maple_tree-the-return-value-of-mas_root_expand-is-not-used.patch maple_tree-not-necessary-to-check-index-last-again.patch maple_tree-refine-mas_store_root-on-storing-null.patch maple_tree-add-a-test-checking-storing-null.patch