From nobody Sun Feb 8 06:47:06 2026 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (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 D6EC11C7B97 for ; Wed, 7 Aug 2024 07:31:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723015897; cv=none; b=Dpzw4ARLoKj+C8GzAwjzP5fbq9zH1fyK9aAGD03nKgqrFI9aJB7cBFiEFMrkuJImslQJtc0vwzGbPOUCbokkfm9ALeIdLqrnreSEQIe3CpsRy51krx+ZT3p7NTRorl6wHHhXy4co8t17s7FM5KQje91uHaPPcL7MwNhIPFqLWVM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723015897; c=relaxed/simple; bh=wU+mvmFmyXxD/VfwSu8JkQrOHqzi5LfMKdgy7Mj74U4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LmrUK4Un2sTuAK2ZV+yoKCRVoM6QJtS4kojZCAJIQXsrXSaY09j6D00UMP8HZ7e1/ehLvdmnIuGs9+l4XI/WC7YW9lvH8I0jNBvPwCAnKYkOpr3WN6QY3UB4QPoBScAJjab57/xma9j1Jj54EUb6AZfZEWa64XSRsSgZG744XwY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=S7hzn6CK; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="S7hzn6CK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1723015893; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=71u6PF0T766CyIr04AjwEpJvSI8v+1Ntw3LK3owxVuQ=; b=S7hzn6CKgeU8NUSo5qaEz9OYqL8WWvlMR+LmOe8Y/UlrOUNKsnVkVOCetzQWkEY83W45FXkp8e7FpVKaA+dHQpvjviTrReQmZjRrJ4FG4ksX0FJthSBIBnU9zIXjdwLHcrHvCtlr088GWMRqbmjZ7bx0tdUsIbGzLdIdf2aT4Kk= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032014031;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=17;SR=0;TI=SMTPD_---0WCI9Fpo_1723015891; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0WCI9Fpo_1723015891) by smtp.aliyun-inc.com; Wed, 07 Aug 2024 15:31:31 +0800 From: Baolin Wang To: akpm@linux-foundation.org, hughd@google.com Cc: willy@infradead.org, david@redhat.com, wangkefeng.wang@huawei.com, chrisl@kernel.org, ying.huang@intel.com, 21cnbao@gmail.com, ryan.roberts@arm.com, shy828301@gmail.com, ziy@nvidia.com, ioworker0@gmail.com, da.gomez@samsung.com, p.raghav@samsung.com, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 04/10] mm: shmem: return number of pages beeing freed in shmem_free_swap Date: Wed, 7 Aug 2024 15:31:09 +0800 Message-Id: <997c9f9694cabfb74505a866b335da9453fa6994.1723012159.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Daniel Gomez Both shmem_free_swap callers expect the number of pages being freed. In the large folios context, this needs to support larger values other than 0 (used as 1 page being freed) and -ENOENT (used as 0 pages being freed). In preparation for large folios adoption, make shmem_free_swap routine return the number of pages being freed. So, returning 0 in this context, means 0 pages being freed. While we are at it, changing to use free_swap_and_cache_nr() to free large order swap entry by Baolin Wang. Suggested-by: Matthew Wilcox Signed-off-by: Daniel Gomez Signed-off-by: Baolin Wang --- mm/shmem.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index 02fb188d627f..d0d54939da48 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -856,18 +856,22 @@ static void shmem_delete_from_page_cache(struct folio= *folio, void *radswap) } =20 /* - * Remove swap entry from page cache, free the swap and its page cache. + * Remove swap entry from page cache, free the swap and its page cache. Re= turns + * the number of pages being freed. 0 means entry not found in XArray (0 p= ages + * being freed). */ -static int shmem_free_swap(struct address_space *mapping, - pgoff_t index, void *radswap) +static long shmem_free_swap(struct address_space *mapping, + pgoff_t index, void *radswap) { + int order =3D xa_get_order(&mapping->i_pages, index); void *old; =20 old =3D xa_cmpxchg_irq(&mapping->i_pages, index, radswap, NULL, 0); if (old !=3D radswap) - return -ENOENT; - free_swap_and_cache(radix_to_swp_entry(radswap)); - return 0; + return 0; + free_swap_and_cache_nr(radix_to_swp_entry(radswap), 1 << order); + + return 1 << order; } =20 /* @@ -1019,7 +1023,7 @@ static void shmem_undo_range(struct inode *inode, lof= f_t lstart, loff_t lend, if (xa_is_value(folio)) { if (unfalloc) continue; - nr_swaps_freed +=3D !shmem_free_swap(mapping, + nr_swaps_freed +=3D shmem_free_swap(mapping, indices[i], folio); continue; } @@ -1086,14 +1090,17 @@ static void shmem_undo_range(struct inode *inode, l= off_t lstart, loff_t lend, folio =3D fbatch.folios[i]; =20 if (xa_is_value(folio)) { + long swaps_freed; + if (unfalloc) continue; - if (shmem_free_swap(mapping, indices[i], folio)) { + swaps_freed =3D shmem_free_swap(mapping, indices[i], folio); + if (!swaps_freed) { /* Swap was replaced by page: retry */ index =3D indices[i]; break; } - nr_swaps_freed++; + nr_swaps_freed +=3D swaps_freed; continue; } =20 --=20 2.39.3