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 3BF18253954; Fri, 24 Oct 2025 17:10:57 +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=1761325857; cv=none; b=mND3exUsqZWDrVZ6vt8aA6a1K++u0ZZasIy0bMtZBcOjF5Vnpim+4d7O4Z8yzzC0qrJ4ZCYKQzqDx8eFDmw6wsvrBK5jn2dB0BF2aWh5UfgJA4e2N1xbWONlT2g6vJ9kiCskvTU5Sf8rXQRz4vMz9JgmDXSAL1S+zEXXA/GLN38= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761325857; c=relaxed/simple; bh=iEjOOLJ0dXWgQLfSaNu50Gnh2bsbo1K+G0/Cr26Du2c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rSH3kMIzskVYmWqrqB1B2IWWDYF4CCZZ8mYyPnvuv/LhCJ4jiffoKvMxc9GCupmkWFHkpLZKiOV+HPXmQdg5fEQI/6D3k+KGXHB0UETZ7FDwjRtamLVNkS18edc6RNFLFAMoeQ5ymlgaaNXXBwZVSbdCBjK0FlZ2hhnxEalv/Y8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=A8IPDrVN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="A8IPDrVN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13979C4CEF1; Fri, 24 Oct 2025 17:10:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1761325857; bh=iEjOOLJ0dXWgQLfSaNu50Gnh2bsbo1K+G0/Cr26Du2c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=A8IPDrVNYiQa3GUAtiE47yFrWSSEVd+gQTz4uX2UJJZicC+qtu9fKU07HXxX/Ul/M 1uLQBt12x/1J7zx2E3Hj+FKvScMyVSCL6E9hUh9+P9+ifddZYf8nGfoGrVpghQWBCc ycMPXACXh/Hn1S03m6zdG/wgLW6hlfY+8aC323pw9v+bkHj3ugWyMm982ZSeG7484B lpN1A4ew6YkKlcPCxciQpsf8qPNGJeHd476xrjE9mXtcNQrRX7cqfDUCsT4exdc2dn KatlOGavhISWUQePX5BT6m2rrnfHyth/mgkwyYYdZDmTxapT3BwYbh46BgrS0WHWX2 WmqyoeOGygQ1Q== Date: Fri, 24 Oct 2025 10:10:56 -0700 From: "Darrick J. Wong" To: "Matthew Wilcox (Oracle)" Cc: linux-fsdevel@vger.kernel.org, Christian Brauner , linux-xfs@vger.kernel.org Subject: Re: [PATCH 07/10] iomap: Use folio_next_pos() Message-ID: <20251024171056.GJ4015566@frogsfrogsfrogs> References: <20251024170822.1427218-1-willy@infradead.org> <20251024170822.1427218-8-willy@infradead.org> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251024170822.1427218-8-willy@infradead.org> On Fri, Oct 24, 2025 at 06:08:15PM +0100, Matthew Wilcox (Oracle) wrote: > This is one instruction more efficient than open-coding folio_pos() + > folio_size(). It's the equivalent of (x + y) << z rather than > x << z + y << z. > > Signed-off-by: Matthew Wilcox (Oracle) > Cc: Christian Brauner > Cc: "Darrick J. Wong" > Cc: linux-xfs@vger.kernel.org Looks like a nice win, even if a small one Reviewed-by: "Darrick J. Wong" --D > --- > fs/iomap/buffered-io.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 8b847a1e27f1..32a27f36372d 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -707,7 +707,7 @@ static int __iomap_write_begin(const struct iomap_iter *iter, > * are not changing pagecache contents. > */ > if (!(iter->flags & IOMAP_UNSHARE) && pos <= folio_pos(folio) && > - pos + len >= folio_pos(folio) + folio_size(folio)) > + pos + len >= folio_next_pos(folio)) > return 0; > > ifs = ifs_alloc(iter->inode, folio, iter->flags); > @@ -1097,8 +1097,7 @@ static void iomap_write_delalloc_ifs_punch(struct inode *inode, > if (!ifs) > return; > > - last_byte = min_t(loff_t, end_byte - 1, > - folio_pos(folio) + folio_size(folio) - 1); > + last_byte = min_t(loff_t, end_byte - 1, folio_next_pos(folio) - 1); > first_blk = offset_in_folio(folio, start_byte) >> blkbits; > last_blk = offset_in_folio(folio, last_byte) >> blkbits; > for (i = first_blk; i <= last_blk; i++) { > @@ -1129,8 +1128,7 @@ static void iomap_write_delalloc_punch(struct inode *inode, struct folio *folio, > * Make sure the next punch start is correctly bound to > * the end of this data range, not the end of the folio. > */ > - *punch_start_byte = min_t(loff_t, end_byte, > - folio_pos(folio) + folio_size(folio)); > + *punch_start_byte = min_t(loff_t, end_byte, folio_next_pos(folio)); > } > > /* > @@ -1170,7 +1168,7 @@ static void iomap_write_delalloc_scan(struct inode *inode, > start_byte, end_byte, iomap, punch); > > /* move offset to start of next folio in range */ > - start_byte = folio_pos(folio) + folio_size(folio); > + start_byte = folio_next_pos(folio); > folio_unlock(folio); > folio_put(folio); > } > -- > 2.47.2 >