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 31774156F28 for ; Sun, 1 Jun 2025 05:47:35 +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=1748756855; cv=none; b=dDuIOVPB8GlmZP6MJfj1Bk+9Yd3dEQUH7wIrc/6IWywKd0a7p9Cy1xG3kjUxelnGcSuJgtINBQ8lYsFbe/yvNjGjZ52+z+3r1v8bJ1/2WYToLjGRD4N5L30uGYuJsUPfA/NOAlvIpMV1T0KjJwIPj1lO8z0HxuK4dHLJv4+4q9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748756855; c=relaxed/simple; bh=YOHBl1fQXtuM1cygVYTAgBdXi9+sOVgbmXIM3FFx6KM=; h=Date:To:From:Subject:Message-Id; b=HD8IyTrCmgFdCOBCfExr5+3CVVNr+4MTz5oHKX3Is86Pm11eYkutuZAy+z+Z1ZZPkwTMrVIpS+TdukGYCCv9uUU6AhyhDp2o+sfmyhb7Nxd6ntnfWEiPQpA44Y8Ehv7oXJokLGkDRMhN4XZc1lhcobEboNCbzha97JGKRfUBxEU= 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=rLZsxcIi; 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="rLZsxcIi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04A5BC4CEED; Sun, 1 Jun 2025 05:47:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1748756855; bh=YOHBl1fQXtuM1cygVYTAgBdXi9+sOVgbmXIM3FFx6KM=; h=Date:To:From:Subject:From; b=rLZsxcIiw4Ja5uZS+VjCx32vg6f5sEdXUQOQh28FfhECSXIc+v5+fVxtcKsakQJu3 hPAhlHO9+DjUUlxNfM6ihfu8Zub5wNZ0fKO+H4JJ4uPFp4zHvDqyVUSUxWt38/0o8u zltjs6YXgwbajZMBz5XOJfEcs7vJBSvxctrxEDDc= Date: Sat, 31 May 2025 22:47:34 -0700 To: mm-commits@vger.kernel.org,peterx@redhat.com,kirill.shutemov@linux.intel.com,jhubbard@nvidia.com,jgg@ziepe.ca,david@redhat.com,jannh@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-gup-update-comment-explaining-why-gup_fast-disables-irqs.patch removed from -mm tree Message-Id: <20250601054735.04A5BC4CEED@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/gup: update comment explaining why gup_fast() disables IRQs has been removed from the -mm tree. Its filename was mm-gup-update-comment-explaining-why-gup_fast-disables-irqs.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: Jann Horn Subject: mm/gup: update comment explaining why gup_fast() disables IRQs Date: Wed, 28 May 2025 23:06:17 +0200 The current comment in gup_fast() talks about "IPIs that come from THPs splitting", which is outdated and refers to the old THP splitting implementation that was removed in commit ad0bed24e98b ("thp: drop all split_huge_page()-related code"), which landed in v4.5. Before then, THP splitting involved a pmdp_splitting_flush(), which sent an IPI to serialize against gup_fast(). Nowadays, we use tlb_remove_table_sync_one() to send IPIs that serialize against gup_fast(); this is used, for example, in THP *collapsing* to stop gup_fast() walks of a page table before depositing it. Link: https://lkml.kernel.org/r/20250528-gup-irq-comment-fix-v1-1-b9d83c345333@google.com Signed-off-by: Jann Horn Cc: David Hildenbrand Cc: Jason Gunthorpe Cc: John Hubbard Cc: Kirill A. Shuemov Cc: Peter Xu Signed-off-by: Andrew Morton --- mm/gup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/gup.c~mm-gup-update-comment-explaining-why-gup_fast-disables-irqs +++ a/mm/gup.c @@ -3299,7 +3299,7 @@ static unsigned long gup_fast(unsigned l * include/asm-generic/tlb.h for more details. * * We do not adopt an rcu_read_lock() here as we also want to block IPIs - * that come from THPs splitting. + * that come from callers of tlb_remove_table_sync_one(). */ local_irq_save(flags); gup_fast_pgd_range(start, end, gup_flags, pages, &nr_pinned); _ Patches currently in -mm which might be from jannh@google.com are mm-hugetlb-unshare-page-tables-during-vma-split-not-before.patch mm-hugetlb-unshare-page-tables-during-vma-split-not-before-v2.patch mm-hugetlb-fix-huge_pmd_unshare-vs-gup-fast-race.patch