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 67567212F98 for ; Sun, 18 Jan 2026 20:16:12 +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=1768767372; cv=none; b=E1sI8z1PfXiMlBMzB3YB9WeKdgNh2uWfkzZkfhu5/VKHlTn3LladiUggolAu+Smn++h+QVcD7pT6nIj1tJML+IFi2em4w3Wz/mMmr1BQmLHis47X/EfBuYVCAbuLY7CMQ6AI7vJeR2uAAFUbwMTQ17XcfhRdajZqXlHf/3rvVYY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768767372; c=relaxed/simple; bh=vbc+zHQTcPQFMEkP/FbfRnpGShnfAJLlD93BF7MTYP0=; h=Date:To:From:Subject:Message-Id; b=ig3WIiMnFbhO/I+KrEVRa38a2XzET+OulB+LLKUh18rwtWtEn5WOn6TiX3DKCxFmC8R/mOEYlRVKtPJAm0k25+ZCwIjzY8ZhsSop8inz9VICQDfqKZngHKzdaAgUSfIesXHSNl65JB/sT6xQcUt1gIzBanwYg8dBlYLFJlsRaJ0= 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=KU/JZomF; 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="KU/JZomF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2EE1C116D0; Sun, 18 Jan 2026 20:16:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1768767372; bh=vbc+zHQTcPQFMEkP/FbfRnpGShnfAJLlD93BF7MTYP0=; h=Date:To:From:Subject:From; b=KU/JZomFHHLgVQrUXpIM1qGY1qicvoQvcOf4BV3mXsN5vSdemVOxqT1TQndG4of9a ojt/P6MXaLwjP36xFjA9HTE2EtA0TgdSkveb4csZBQj8/N8ZN72/cNZdabaQchx65a Rej9txCQug5MkSoKKTnhozP5PxX4iqRFeTWkW+6I= Date: Sun, 18 Jan 2026 12:16:11 -0800 To: mm-commits@vger.kernel.org,zokeefe@google.com,ziy@nvidia.com,ryan.roberts@arm.com,npache@redhat.com,mhiramat@kernel.org,mathieu.desnoyers@efficios.com,lorenzo.stoakes@oracle.com,lianux.mm@gmail.com,liam.howlett@oracle.com,lance.yang@linux.dev,dev.jain@arm.com,david@kernel.org,Branden.Moore@amd.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,shivankg@amd.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-khugepaged-retry-with-sync-writeback-for-madv_collapse.patch added to mm-unstable branch Message-Id: <20260118201611.F2EE1C116D0@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/khugepaged: retry with sync writeback for MADV_COLLAPSE has been added to the -mm mm-unstable branch. Its filename is mm-khugepaged-retry-with-sync-writeback-for-madv_collapse.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-retry-with-sync-writeback-for-madv_collapse.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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: Shivank Garg Subject: mm/khugepaged: retry with sync writeback for MADV_COLLAPSE Date: Sun, 18 Jan 2026 19:09:43 +0000 When MADV_COLLAPSE is called on file-backed mappings (e.g., executable text sections), the pages may still be dirty from recent writes. collapse_file() will trigger async writeback and fail with SCAN_PAGE_DIRTY_OR_WRITEBACK (-EAGAIN). MADV_COLLAPSE is a synchronous operation where userspace expects immediate results. If the collapse fails due to dirty pages, perform synchronous writeback on the specific range and retry once. This avoids spurious failures for freshly written executables while avoiding unnecessary synchronous I/O for mappings that are already clean. Link: https://lkml.kernel.org/r/20260118190939.8986-7-shivankg@amd.com Signed-off-by: Shivank Garg Reported-by: Branden Moore Closes: https://lore.kernel.org/all/4e26fe5e-7374-467c-a333-9dd48f85d7cc@amd.com Fixes: 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") Suggested-by: David Hildenbrand Tested-by: Lance Yang Cc: Baolin Wang Cc: Barry Song Cc: Dev Jain Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Nico Pache Cc: Ryan Roberts Cc: wang lian Cc: Zach O'Keefe Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/mm/khugepaged.c~mm-khugepaged-retry-with-sync-writeback-for-madv_collapse +++ a/mm/khugepaged.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include "internal.h" @@ -2788,7 +2789,9 @@ int madvise_collapse(struct vm_area_stru for (addr = hstart; addr < hend; addr += HPAGE_PMD_SIZE) { int result = SCAN_FAIL; + bool triggered_wb = false; +retry: if (!mmap_locked) { cond_resched(); mmap_read_lock(mm); @@ -2809,8 +2812,20 @@ int madvise_collapse(struct vm_area_stru mmap_read_unlock(mm); mmap_locked = false; + *lock_dropped = true; result = hpage_collapse_scan_file(mm, addr, file, pgoff, cc); + + if (result == SCAN_PAGE_DIRTY_OR_WRITEBACK && !triggered_wb && + mapping_can_writeback(file->f_mapping)) { + loff_t lstart = (loff_t)pgoff << PAGE_SHIFT; + loff_t lend = lstart + HPAGE_PMD_SIZE - 1; + + filemap_write_and_wait_range(file->f_mapping, lstart, lend); + triggered_wb = true; + fput(file); + goto retry; + } fput(file); } else { result = hpage_collapse_scan_pmd(mm, vma, addr, _ Patches currently in -mm which might be from shivankg@amd.com are mm-khugepaged-map-dirty-writeback-pages-failures-to-eagain.patch mm-khugepaged-retry-with-sync-writeback-for-madv_collapse.patch mm-khugepaged-remove-unnecessary-goto-skip-label.patch mm-khugepaged-count-small-vmas-towards-scan-limit.patch mm-khugepaged-count-small-vmas-towards-scan-limit-fix.patch mm-khugepaged-change-collapse_pte_mapped_thp-to-return-void.patch mm-khugepaged-use-enum-scan_result-for-result-variables-and-return-types.patch mm-khugepaged-make-khugepaged_collapse_control-static.patch