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 DFA6F12D758 for ; Tue, 10 Jun 2025 21:08:44 +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=1749589725; cv=none; b=SkZWf0rc9K2c9SdISzKNwgrpw9fQsvubvJwPAEBuDoWwIeM1zvpMJnJKB5v7XPpx/PnqG8jHtauwrjAvt2iG7M2xUBKVlMUP7aJFc7ePKNytcZbFHBWfENRKdsTuAjSbrGDV7wnTHIW1BeI0EmLE1XcTSP0/J5USmvsW8yptmDg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749589725; c=relaxed/simple; bh=9+EahQBSYaTHKqfVlTpc4TpSLbiXjh4nYp/bRAIZ81M=; h=Date:To:From:Subject:Message-Id; b=knzzwPXaSOup3AgnrSQTLkfufvXEnlVe/bKBS4v/D5OG6/WBTTELyeJemfN6Pce1kdzIj0kacWLB8NdyC/Paz3HUrFV1vygcOoWvHjj8FvLm087/DpOo+2bUwOhfZsRJwzNmiciIEpXxYA15ljkq2cNnotKcoOHd4jrJKUmXjXA= 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=K60TbFVP; 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="K60TbFVP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C3ECC4CEED; Tue, 10 Jun 2025 21:08:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1749589724; bh=9+EahQBSYaTHKqfVlTpc4TpSLbiXjh4nYp/bRAIZ81M=; h=Date:To:From:Subject:From; b=K60TbFVPDuUPkIBY5uMaDvsh4OmJgdXgcWgqK3d7TNkjzKTw3Bk/JrKrWyOgP9M6D Kn+pJsFqm6GcztVJABPETNpZa6LnBAQkpXaVZz9+vchs7HLoZLQWCi5a8XUOHV0KN+ ib31DrUIheMapoQiCJcDaj3tyFC3h6zELXVScQ9g= Date: Tue, 10 Jun 2025 14:08:43 -0700 To: mm-commits@vger.kernel.org,willy@infradead.org,nphamcs@gmail.com,hughd@google.com,hannes@cmpxchg.org,chengming.zhou@linux.dev,baolin.wang@linux.alibaba.com,hch@lst.de,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-split-out-a-writeout-helper-from-pageout.patch added to mm-unstable branch Message-Id: <20250610210844.3C3ECC4CEED@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: split out a writeout helper from pageout has been added to the -mm mm-unstable branch. Its filename is mm-split-out-a-writeout-helper-from-pageout.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-split-out-a-writeout-helper-from-pageout.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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Christoph Hellwig Subject: mm: split out a writeout helper from pageout Date: Tue, 10 Jun 2025 07:49:37 +0200 Patch series "stop passing a writeback_control to swap/shmem writeout", v3. This series was intended to remove the last remaining users of AOP_WRITEPAGE_ACTIVATE after my other pending patches removed the rest, but spectacularly failed at that. But instead it nicely improves the code, and removes two pointers from struct writeback_control. This patch (of 6): Move the code to write back swap / shmem folios into a self-contained helper to keep prepare for refactoring it. Link: https://lkml.kernel.org/r/20250610054959.2057526-1-hch@lst.de Link: https://lkml.kernel.org/r/20250610054959.2057526-2-hch@lst.de Signed-off-by: Christoph Hellwig Cc: Baolin Wang Cc: Chengming Zhou Cc: Hugh Dickins Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Nhat Pham Signed-off-by: Andrew Morton --- mm/vmscan.c | 94 +++++++++++++++++++++++++------------------------- 1 file changed, 48 insertions(+), 46 deletions(-) --- a/mm/vmscan.c~mm-split-out-a-writeout-helper-from-pageout +++ a/mm/vmscan.c @@ -652,14 +652,55 @@ typedef enum { PAGE_CLEAN, } pageout_t; +static pageout_t writeout(struct folio *folio, struct address_space *mapping, + struct swap_iocb **plug, struct list_head *folio_list) +{ + struct writeback_control wbc = { + .sync_mode = WB_SYNC_NONE, + .nr_to_write = SWAP_CLUSTER_MAX, + .range_start = 0, + .range_end = LLONG_MAX, + .for_reclaim = 1, + .swap_plug = plug, + }; + int res; + + folio_set_reclaim(folio); + + /* + * The large shmem folio can be split if CONFIG_THP_SWAP is not enabled + * or we failed to allocate contiguous swap entries. + */ + if (shmem_mapping(mapping)) { + if (folio_test_large(folio)) + wbc.list = folio_list; + res = shmem_writeout(folio, &wbc); + } else { + res = swap_writeout(folio, &wbc); + } + + if (res < 0) + handle_write_error(mapping, folio, res); + if (res == AOP_WRITEPAGE_ACTIVATE) { + folio_clear_reclaim(folio); + return PAGE_ACTIVATE; + } + + /* synchronous write? */ + if (!folio_test_writeback(folio)) + folio_clear_reclaim(folio); + + trace_mm_vmscan_write_folio(folio); + node_stat_add_folio(folio, NR_VMSCAN_WRITE); + return PAGE_SUCCESS; +} + /* * pageout is called by shrink_folio_list() for each dirty folio. */ static pageout_t pageout(struct folio *folio, struct address_space *mapping, struct swap_iocb **plug, struct list_head *folio_list) { - int (*writeout)(struct folio *, struct writeback_control *); - /* * We no longer attempt to writeback filesystem folios here, other * than tmpfs/shmem. That's taken care of in page-writeback. @@ -690,51 +731,12 @@ static pageout_t pageout(struct folio *f } return PAGE_KEEP; } - if (shmem_mapping(mapping)) - writeout = shmem_writeout; - else if (folio_test_anon(folio)) - writeout = swap_writeout; - else - return PAGE_ACTIVATE; - - if (folio_clear_dirty_for_io(folio)) { - int res; - struct writeback_control wbc = { - .sync_mode = WB_SYNC_NONE, - .nr_to_write = SWAP_CLUSTER_MAX, - .range_start = 0, - .range_end = LLONG_MAX, - .for_reclaim = 1, - .swap_plug = plug, - }; - - /* - * The large shmem folio can be split if CONFIG_THP_SWAP is - * not enabled or contiguous swap entries are failed to - * allocate. - */ - if (shmem_mapping(mapping) && folio_test_large(folio)) - wbc.list = folio_list; - folio_set_reclaim(folio); - res = writeout(folio, &wbc); - if (res < 0) - handle_write_error(mapping, folio, res); - if (res == AOP_WRITEPAGE_ACTIVATE) { - folio_clear_reclaim(folio); - return PAGE_ACTIVATE; - } - - if (!folio_test_writeback(folio)) { - /* synchronous write? */ - folio_clear_reclaim(folio); - } - trace_mm_vmscan_write_folio(folio); - node_stat_add_folio(folio, NR_VMSCAN_WRITE); - return PAGE_SUCCESS; - } - - return PAGE_CLEAN; + if (!shmem_mapping(mapping) && !folio_test_anon(folio)) + return PAGE_ACTIVATE; + if (!folio_clear_dirty_for_io(folio)) + return PAGE_CLEAN; + return writeout(folio, mapping, plug, folio_list); } /* _ Patches currently in -mm which might be from hch@lst.de are mm-split-out-a-writeout-helper-from-pageout.patch mm-stop-passing-a-writeback_control-structure-to-shmem_writeout.patch mm-tidy-up-swap_writeout.patch mm-stop-passing-a-writeback_control-structure-to-__swap_writepage.patch mm-stop-passing-a-writeback_control-structure-to-swap_writeout.patch mm-remove-the-for_reclaim-field-from-struct-writeback_control.patch