From nobody Tue Feb 10 00:01:08 2026 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (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 8144723184F; Fri, 16 May 2025 10:11:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.151 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747390288; cv=none; b=oapsMz0o/77Un2mqhu1yx8KCWnEp7zIilhsZ7a9JEJiQw3g26DEOFqE1JDsdWxFI0gILuI0OJTlGwkGAGnXESnHIm8gh1hMSgwCQx/wSDe0pYudls04TYlSFTimYqjx4okC7NM1CdxYF/iSjS204ButSVOfZ77cHipfoDsj4hLQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747390288; c=relaxed/simple; bh=YurZ2FzxP3Y4no0Ti7m/BM4bZkV94wobNRj9pR79ess=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hW4KkDBJgajYRIq0Q7cspNoL5bT31oiDFnghuT9uTk/1f3Z7lkSvh+4kdpDItg9minQd2QBDj3RTLVlazZGj/tr3pSUowsaxOrY/bE5jN4f9Yy2xP8JILteU2GRcoEuk5Sc6ZkVklOKHr81WP35ZUbkmy3otIOalFf1NanNCiy8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=samsung.com; spf=pass smtp.mailfrom=pankajraghav.com; arc=none smtp.client-ip=80.241.56.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=samsung.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pankajraghav.com Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:b231:465::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4ZzNCG6SMtz9tCG; Fri, 16 May 2025 12:11:22 +0200 (CEST) From: Pankaj Raghav To: "Darrick J . Wong" , hch@lst.de, willy@infradead.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, David Hildenbrand , linux-fsdevel@vger.kernel.org, mcgrof@kernel.org, gost.dev@samsung.com, Andrew Morton , kernel@pankajraghav.com, Pankaj Raghav Subject: [RFC 3/3] iomap: use LARGE_ZERO_PAGE in iomap_dio_zero() Date: Fri, 16 May 2025 12:10:54 +0200 Message-ID: <20250516101054.676046-4-p.raghav@samsung.com> In-Reply-To: <20250516101054.676046-1-p.raghav@samsung.com> References: <20250516101054.676046-1-p.raghav@samsung.com> 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 X-Rspamd-Queue-Id: 4ZzNCG6SMtz9tCG Content-Type: text/plain; charset="utf-8" Use LARGE_ZERO_PAGE instead of custom allocated 64k zero pages. The downside is we might end up using ZERO_PAGE on systems that do not enable LARGE_ZERO_PAGE feature. Signed-off-by: Pankaj Raghav --- fs/iomap/direct-io.c | 31 +++++++++---------------------- 1 file changed, 9 insertions(+), 22 deletions(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 844261a31156..6a2b6726a156 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -29,13 +29,6 @@ #define IOMAP_DIO_WRITE (1U << 30) #define IOMAP_DIO_DIRTY (1U << 31) =20 -/* - * Used for sub block zeroing in iomap_dio_zero() - */ -#define IOMAP_ZERO_PAGE_SIZE (SZ_64K) -#define IOMAP_ZERO_PAGE_ORDER (get_order(IOMAP_ZERO_PAGE_SIZE)) -static struct page *zero_page; - struct iomap_dio { struct kiocb *iocb; const struct iomap_dio_ops *dops; @@ -290,23 +283,29 @@ static int iomap_dio_zero(const struct iomap_iter *it= er, struct iomap_dio *dio, { struct inode *inode =3D file_inode(dio->iocb->ki_filp); struct bio *bio; + int nr_vecs =3D max(1, i_blocksize(inode) / ZERO_LARGE_PAGE_SIZE); =20 if (!len) return 0; /* * Max block size supported is 64k */ - if (WARN_ON_ONCE(len > IOMAP_ZERO_PAGE_SIZE)) + if (WARN_ON_ONCE(len > SZ_64K)) return -EINVAL; =20 - bio =3D iomap_dio_alloc_bio(iter, dio, 1, REQ_OP_WRITE | REQ_SYNC | REQ_I= DLE); + bio =3D iomap_dio_alloc_bio(iter, dio, nr_vecs, REQ_OP_WRITE | REQ_SYNC |= REQ_IDLE); fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits, GFP_KERNEL); bio->bi_iter.bi_sector =3D iomap_sector(&iter->iomap, pos); bio->bi_private =3D dio; bio->bi_end_io =3D iomap_dio_bio_end_io; =20 - __bio_add_page(bio, zero_page, len, 0); + while (len) { + unsigned int io_len =3D min_t(unsigned int, len, ZERO_LARGE_PAGE_SIZE); + + __bio_add_page(bio, ZERO_LARGE_PAGE(0), len, 0); + len -=3D io_len; + } iomap_dio_submit_bio(iter, dio, bio, pos); return 0; } @@ -827,15 +826,3 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, return iomap_dio_complete(dio); } EXPORT_SYMBOL_GPL(iomap_dio_rw); - -static int __init iomap_dio_init(void) -{ - zero_page =3D alloc_pages(GFP_KERNEL | __GFP_ZERO, - IOMAP_ZERO_PAGE_ORDER); - - if (!zero_page) - return -ENOMEM; - - return 0; -} -fs_initcall(iomap_dio_init); --=20 2.47.2