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 632443451C6 for ; Thu, 29 Jan 2026 23:25:07 +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=1769729107; cv=none; b=hAAZfQpD2M9TR0YdaTN9RbjZxYGcROPgyMw1HJkTm4jtIljrbXxCesic5+U6j+MYdSZsejLvaaTiE64RDG9xLbV46wjBb0Ms9BhsIasTcsfnYJwgpdzcorIntYjOTJurzhmwdCxj1v51NRVIBhS7eUL1N8MuZ0rOwLfSWeYltvg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769729107; c=relaxed/simple; bh=99Xy8y6FRgMBA+KLO/OIyIF0sMrYqptM+qxe9EuxXQE=; h=Date:To:From:Subject:Message-Id; b=Hk+PX2sUNzVjt8w2qqjMZRfe8Ijf2V1J8Tj8CfEMloRPINhxl5eO1L0fgkXKeB44yQxkpbN76FX2DNdgu7AR1B2F+EN8ppUstsbgIn85Kfv+10O+HHB4qtjYXi6MXiNYZcDcImrDbSoTn2R1D6oiIi89olSrWTHj8Kh37/PsGEs= 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=xzLum2Ew; 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="xzLum2Ew" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDC9FC4CEF7; Thu, 29 Jan 2026 23:25:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1769729106; bh=99Xy8y6FRgMBA+KLO/OIyIF0sMrYqptM+qxe9EuxXQE=; h=Date:To:From:Subject:From; b=xzLum2EwyIdPX6iTZGFUmlk+FD1Pv+/mVGMdi8nzvHdVWAk/jD7ehcKp3GNWeF6sp Zu232SCt+XuAn/2cNKKVBr0BSsjxh/iA2Bb0MSxpkzP+fTi8VOObop+beJFw1+mGPo tPYUlcDU2JXOZiel2O07bvjshLGhsxx22lcDsrrk= Date: Thu, 29 Jan 2026 15:25:06 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,vbabka@suse.cz,surenb@google.com,rppt@kernel.org,rientjes@google.com,mhocko@suse.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,david@kernel.org,bgeffon@google.com,arjunroy@google.com,greenjustin@chromium.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-refactor-vma_map_pages-to-use-vm_insert_pages.patch added to mm-new branch Message-Id: <20260129232506.CDC9FC4CEF7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: refactor vma_map_pages to use vm_insert_pages has been added to the -mm mm-new branch. Its filename is mm-refactor-vma_map_pages-to-use-vm_insert_pages.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-refactor-vma_map_pages-to-use-vm_insert_pages.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 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: Justin Green Subject: mm: refactor vma_map_pages to use vm_insert_pages Date: Wed, 28 Jan 2026 17:56:47 -0500 vma_map_pages currently calls vm_insert_page on each individual page in the mapping, which creates significant overhead because we are repeatedly spinlocking. Instead, we should batch insert pages using vm_insert_pages, which amortizes the cost of the spinlock. Tested through watching hardware accelerated video on a MTK ChromeOS device. This particular path maps both a V4L2 buffer and a GEM allocated buffer into userspace and converts the contents from one pixel format to another. Both vb2_mmap() and mtk_gem_object_mmap() exercise this pathway. Link: https://lkml.kernel.org/r/20260128225648.2938636-1-greenjustin@chromium.org Signed-off-by: Justin Green Acked-by: Brian Geffon Reviewed-by: Matthew Wilcox (Oracle) Reviewed-by: Arjun Roy Cc: David Hildenbrand Cc: David Rientjes Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/memory.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) --- a/mm/memory.c~mm-refactor-vma_map_pages-to-use-vm_insert_pages +++ a/mm/memory.c @@ -2568,7 +2568,6 @@ static int __vm_map_pages(struct vm_area { unsigned long count = vma_pages(vma); unsigned long uaddr = vma->vm_start; - int ret, i; /* Fail if the user requested offset is beyond the end of the object */ if (offset >= num) @@ -2578,14 +2577,7 @@ static int __vm_map_pages(struct vm_area if (count > num - offset) return -ENXIO; - for (i = 0; i < count; i++) { - ret = vm_insert_page(vma, uaddr, pages[offset + i]); - if (ret < 0) - return ret; - uaddr += PAGE_SIZE; - } - - return 0; + return vm_insert_pages(vma, uaddr, pages + offset, &count); } /** _ Patches currently in -mm which might be from greenjustin@chromium.org are mm-refactor-vma_map_pages-to-use-vm_insert_pages.patch