From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f65.google.com ([209.85.214.65]:35839 "EHLO mail-it0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754961AbeE2Ogo (ORCPT ); Tue, 29 May 2018 10:36:44 -0400 Received: by mail-it0-f65.google.com with SMTP id q72-v6so18829723itc.0 for ; Tue, 29 May 2018 07:36:43 -0700 (PDT) Subject: Re: [PATCH 1/3] mpage: mpage_readpages() should submit IO as read-ahead To: Andrew Morton Cc: linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk References: <1527177774-21414-1-git-send-email-axboe@kernel.dk> <1527177774-21414-2-git-send-email-axboe@kernel.dk> <20180524124306.1d8833f06366fcad29506182@linux-foundation.org> From: Jens Axboe Message-ID: <8cdea5ed-c3ef-f4f3-edea-208ebc9b45ca@kernel.dk> Date: Tue, 29 May 2018 08:36:41 -0600 MIME-Version: 1.0 In-Reply-To: <20180524124306.1d8833f06366fcad29506182@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 5/24/18 1:43 PM, Andrew Morton wrote: > On Thu, 24 May 2018 10:02:52 -0600 Jens Axboe wrote: > >> a_ops->readpages() is only ever used for read-ahead, yet we don't >> flag the IO being submitted as such. Fix that up. Any file system >> that uses mpage_readpages() as it's ->readpages() implementation >> will now get this right. >> >> Signed-off-by: Jens Axboe >> --- >> fs/mpage.c | 17 +++++++++-------- >> 1 file changed, 9 insertions(+), 8 deletions(-) >> >> diff --git a/fs/mpage.c b/fs/mpage.c >> index b7e7f570733a..0a5474237f5e 100644 >> --- a/fs/mpage.c >> +++ b/fs/mpage.c >> @@ -146,7 +146,7 @@ static struct bio * >> do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, >> sector_t *last_block_in_bio, struct buffer_head *map_bh, >> unsigned long *first_logical_block, get_block_t get_block, >> - gfp_t gfp) >> + gfp_t gfp, bool is_readahead) > > That's a lot of arguments. > > I suspect we'll have a faster kernel if we mark this __always_inline. > I think my ancient "This isn't called much at all" over > mpage_readpage() remains true. Almost all callers come in via > mpage_readpages(), which would benefit from the inlining. But mpage.o > gets 1.5k fatter. hm. Was going to send out a v2, but would be nice to get some consensus on what you prefer here. I can either do the struct version, or I can keep it as-is (going from 8 to 9 arguments). For the struct version, I'd prefer to do that as a prep patch, so the functional change is clear. -- Jens Axboe