From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 2F6FA3911D5 for ; Thu, 17 Sep 2026 08:09:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789632591; cv=none; b=k901ngL7A9ACb+u3MxgkebKGdeQg8fI0/k/FpTuLz8ptK/KUnYvXnq+gfGzCQVbSMLiM0AaDYFNgm34fgmifIg/b1iPe2vua/X/tiIzQ4BUpUk2+c6GEcEa4pmfHKXUiFTzTfj1sCn+ytJsOJJnVNgOiFAO9Ru6NshS34SBlbLI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789632591; c=relaxed/simple; bh=thxTlFDiUn5m3b2TgEqlNjeAfPL8lcYYZNd7JPe5Uzc=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=tXL1EdA5jluFOTQJMsoXoh+iiPjqyVi+9QaQFQ0XXT5s5m0WciTlBCcmrlfMPRQilXD5wdng7K0hgJ+X/B0h4sh1RzUfery6CfopbvCoE/urMCTS7ZLjTesNzHXiLyM9qeVnClsBYTAnru8whNOgHbgwYXUl8iandja/gFY3Hww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=V61j4DCj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="V61j4DCj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BFE41F000FF; Thu, 17 Sep 2026 08:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789632589; bh=UykKVWBqmzlyI8cYgHwt51rpqVmLZ/BwoeZDabajYo4=; h=Date:Cc:Subject:To:References:From:In-Reply-To; b=V61j4DCj4ah5LSOTCOFsmvR14tPiPu89KoJFUT7ZafNL3UgbTIapTqu9c4t0gxT0N KmhP7HU9NKjSkanSpLbGGaY72xrtuws9ZnRQPywE38umtaTDQVj+FdX6vaImJKi+6z QW1c9rZjNS1SpRxACgIUsCUeExwhe2f1cvHHrql1nADuXe5g3AhjGqYJMZLYq9XwHU MSmZ/R0r09tKlz/ZGWwRAugiXAdA0uLvb38xX1ym5yvlCOSJP4k+H+Xy0BD08EEJXz ajq2SGoOyD3P8J3laf/mYZtWi1tv7lPd67pXeFHs+Kt0lLOuhDlEOqoAUhSupL3Maj 5inw+7e0j5v4A== Message-ID: <6045b4b3-26ef-4d12-b832-7affc9574df0@kernel.org> Date: Thu, 17 Sep 2026 16:09:45 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: chao@kernel.org, Barry Song , Juan Yescas , Dev Jain , linux-kernel@vger.kernel.org, David Hildenbrand , Bo Zhang , Kalesh Singh , Nanzhe Zhao , Pengfei Li , Ryan Roberts Subject: Re: [PATCH v2 08/14] f2fs: optimize small block size large folio read To: Nanzhe Zhao , linux-f2fs-devel@lists.sourceforge.net, Jaegeuk Kim References: <20260915041909.2903887-1-zhaonanzhe@xiaomi.com> <20260915041909.2903887-9-zhaonanzhe@xiaomi.com> Content-Language: en-US From: Chao Yu In-Reply-To: <20260915041909.2903887-9-zhaonanzhe@xiaomi.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/15/26 12:19, Nanzhe Zhao wrote: > The original f2fs_read_data_large_folio() implementation has limited > benefit with a 4KB block size, mainly because updating > read_pages_pending greatly increases the number of spinlock > operations. > > Use len_blks to batch read_pages_pending and iostat updates for > contiguous mapped blocks. If the contiguous mapping covers the whole > folio, skip f2fs_folio_state allocation for that folio. > > Signed-off-by: Nanzhe Zhao > --- > fs/f2fs/data.c | 65 ++++++++++++++++++++++++++++++++++---------------- > 1 file changed, 45 insertions(+), 20 deletions(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index 287d83debf95..09ad5cf0d9aa 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -173,8 +173,9 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task) > continue; > } > > - if (folio_test_large(folio)) { > - struct f2fs_folio_state *ffs = folio->private; > + if (f2fs_folio_has_ffs(folio)) { > + struct f2fs_folio_state *ffs = > + (struct f2fs_folio_state *)folio->private; I just notice that in somewhere, we missed to cast the private field to f2fs_folio_state pointer as below, please take a look. ffs = folio->private; > > spin_lock_irqsave(&ffs->state_lock, flags); > ffs->read_pages_pending -= nr_pages; > @@ -2844,8 +2845,7 @@ static int f2fs_read_data_large_folio(struct inode *inode, > pgoff_t index, offset, next_pgofs = 0; > unsigned max_nr_pages = rac ? readahead_count(rac) : > folio_nr_pages(folio); > - unsigned int nrpages; > - struct f2fs_folio_state *ffs; > + unsigned int nrpages, len_blks; > int ret = 0; > bool folio_in_bio = false; > > @@ -2868,11 +2868,17 @@ static int f2fs_read_data_large_folio(struct inode *inode, > folio_in_bio = false; > index = folio->index; > offset = 0; > - ffs = NULL; > nrpages = folio_nr_pages(folio); > > - for (; nrpages; nrpages--, max_nr_pages--, index++, offset++) { > + for (; nrpages; > + nrpages -= len_blks, max_nr_pages -= len_blks, > + index += len_blks, offset += len_blks) { > sector_t block_nr; > + bool whole_folio_in_bio; > + unsigned int i; > + > + len_blks = 1; > + > /* > * Map blocks using the previous result first. > */ > @@ -2901,13 +2907,31 @@ static int f2fs_read_data_large_folio(struct inode *inode, > got_it: > if ((map.m_flags & F2FS_MAP_MAPPED)) { > block_nr = map.m_pblk + index - map.m_lblk; > - if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), block_nr, > + > + len_blks = min_t(unsigned int, nrpages, max_nr_pages); > + len_blks = min_t(unsigned int, len_blks, > + (unsigned int)(map.m_lblk + map.m_len - index)); > + > + for (i = 0; i < len_blks; i++) { > + if (!f2fs_is_valid_blkaddr(F2FS_I_SB(inode), > + block_nr + i, > DATA_GENERIC_ENHANCE_READ)) { > - ret = -EFSCORRUPTED; > - goto err_out; > + ret = -EFSCORRUPTED; > + goto err_out; > + } > } > + > + /* > + * If an entire folio is added to one bio, > + * folio_end_read() can complete the folio read status > + * without relying on f2fs_folio_state. > + */ > + whole_folio_in_bio = offset == 0 && > + len_blks == folio_nr_pages(folio); > + > } else { > size_t page_offset = offset << PAGE_SHIFT; > + > folio_zero_range(folio, page_offset, PAGE_SIZE); > if (vi && !fsverity_verify_blocks(vi, folio, PAGE_SIZE, page_offset)) { > ret = -EIO; > @@ -2917,15 +2941,13 @@ static int f2fs_read_data_large_folio(struct inode *inode, > } > > /* We must increment read_pages_pending before possible BIOs submitting > - * to prevent from premature folio_end_read() call on folio > + * to prevent from premature folio_end_read() call on folio. > */ > - if (folio_test_large(folio)) { > - ffs = f2fs_ffs_find_or_alloc(folio); > + if (folio_test_large(folio) && !whole_folio_in_bio) { > + f2fs_ffs_find_or_alloc(folio); Need to check return value? Thanks, > > /* set the bitmap to wait */ > - spin_lock_irq(&ffs->state_lock); > - ffs->read_pages_pending++; > - spin_unlock_irq(&ffs->state_lock); > + f2fs_update_read_folio_pending(folio, len_blks); > } > > /* > @@ -2949,17 +2971,20 @@ static int f2fs_read_data_large_folio(struct inode *inode, > * If the page is under writeback, we need to wait for > * its completion to see the correct decrypted data. > */ > - f2fs_wait_on_block_writeback(inode, block_nr); > + for (i = 0; i < len_blks; i++) > + f2fs_wait_on_block_writeback(inode, block_nr + i); > > - if (!bio_add_folio(bio, folio, F2FS_BLKSIZE(F2FS_I_SB(inode)), > + if (!bio_add_folio(bio, folio, > + len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode)), > offset << PAGE_SHIFT)) > goto submit_and_realloc; > > folio_in_bio = true; > - inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); > + for (i = 0; i < len_blks; i++) > + inc_page_count(F2FS_I_SB(inode), F2FS_RD_DATA); > f2fs_update_iostat(F2FS_I_SB(inode), NULL, FS_DATA_READ_IO, > - F2FS_BLKSIZE(F2FS_I_SB(inode))); > - last_block_in_bio = block_nr; > + len_blks * F2FS_BLKSIZE(F2FS_I_SB(inode))); > + last_block_in_bio = block_nr + len_blks - 1; > } > trace_f2fs_read_folio(folio, DATA); > err_out: