Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754752AbdCJEch (ORCPT ); Thu, 9 Mar 2017 23:32:37 -0500 Received: from mx2.suse.de ([195.135.220.15]:40652 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754539AbdCJEcf (ORCPT ); Thu, 9 Mar 2017 23:32:35 -0500 From: NeilBrown To: Jens Axboe , Jack Wang Date: Fri, 10 Mar 2017 15:32:21 +1100 Cc: LKML , Lars Ellenberg , Kent Overstreet , Pavel Machek , Mike Snitzer , Mikulas Patocka , linux-raid@vger.kernel.org, device-mapper development , linux-block@vger.kernel.org Subject: Re: [PATCH v2] blk: improve order of bio handling in generic_make_request() In-Reply-To: <87r328j00i.fsf@notabene.neil.brown.name> References: <87h93blz6g.fsf@notabene.neil.brown.name> <71562c2c-97f4-9a0a-32ec-30e0702ca575@profitbricks.com> <87lgsjj9w8.fsf@notabene.neil.brown.name> <87r328j00i.fsf@notabene.neil.brown.name> Message-ID: <87d1dphhuy.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3292 Lines: 79 --=-=-= Content-Type: text/plain I started looking further at the improvements we can make once generic_make_request is fixed, and realised that I had missed an important detail in this patch. Several places test current->bio_list, and two actually edit the list. With this change, that cannot see the whole lists, so it could cause a regression. So I've revised the patch to make sure that the entire list of queued bios remains visible, and change the relevant code to look at both the new list and the old list. Following that there are some patches which make the rescuer thread optional, and then starts removing it from some easy-to-fix places. The series summary is below. NeilBrown NeilBrown (5): blk: improve order of bio handling in generic_make_request() blk: remove bio_set arg from blk_queue_split() blk: make the bioset rescue_workqueue optional. blk: use non-rescuing bioset for q->bio_split. block_dev: make blkdev_dio_pool a non-rescuing bioset block/bio.c | 39 +++++++++++++++++++++++++++------ block/blk-core.c | 42 ++++++++++++++++++++++++++++------- block/blk-merge.c | 7 +++--- block/blk-mq.c | 4 ++- drivers/block/drbd/drbd_main.c | 2 +- drivers/block/drbd/drbd_req.c | 2 +- drivers/block/pktcdvd.c | 2 +- drivers/block/ps3vram.c | 2 +- drivers/block/rsxx/dev.c | 2 +- drivers/block/umem.c | 2 +- drivers/block/zram/zram_drv.c | 2 +- drivers/lightnvm/rrpc.c | 2 +- drivers/md/bcache/super.c | 4 ++- drivers/md/dm-crypt.c | 2 +- drivers/md/dm-io.c | 2 +- drivers/md/dm.c | 32 +++++++++++++++------------ drivers/md/md.c | 4 ++- drivers/md/raid10.c | 3 ++- drivers/md/raid5-cache.c | 2 +- drivers/s390/block/dcssblk.c | 2 +- drivers/s390/block/xpram.c | 2 +- drivers/target/target_core_iblock.c | 2 +- fs/btrfs/extent_io.c | 4 ++- fs/xfs/xfs_super.c | 2 +- include/linux/bio.h | 2 ++ include/linux/blkdev.h | 3 +-- 26 files changed, 114 insertions(+), 60 deletions(-) --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEG8Yp69OQ2HB7X0l6Oeye3VZigbkFAljCLFUACgkQOeye3VZi gbnoWA/8DKkzvIQ3LnMsWiX4lFZU4391O3AoQadW9ZNtbJwoh3+RRUWur75KTXUa xSlhbhMrLlbsx+BBq9tI7lKQKpHrM3WKCTlWqaEZF7ApgZiZLRstclXjb2+Obz75 DVRSk8ypsfi6RGcFips98/Ol3TrshqBPWnQhuYSZJEAedHJx9/gCVh0d+fbijOLd z7KYXRZVig9jwubcn6eGu82BSFT3BscptaSnAfvinS29wuzmRXyyNcFsL69B8THZ BF3u6A9VHUXtiZNJAIE5xxG7xcEX/yzDsVy5d5KUwAff4Qc9P7szZclT1iCTGz/Q Z00bWb1XRByMmGmE9aVX+9GZy0iHmZuougz0Pv8pKIAI1l6ciZPboG9nibQM1911 XYzdwbv88vdMcZ+iKPyuvASqA58hRB8eZx7S1xkCzBF1rIOe3d4WCxISZmt/KzFs +ktPbyawVaeMO4Dl64bbdDhGtxg4CohdRGrUGUoGXRUSEuQKcEVnQXA9PxaRad2f PijZTF7n9UJH3m/DM32R1+jCYuFw0kkyV5iOslwJFp5xJ2s1wJbJoTJg65CCgTyx Xid1VKxhSvjXZZjqC05gJVaXwbL5rdnpFDlkbbK7mlY7yYCegQaXwuVZ+Zd6sM4l +f8wd+NdwI9YT01WCo+Y+o0sVzrFagxsHqGjPT9ezNLJ/Wtz59Q= =bzg3 -----END PGP SIGNATURE----- --=-=-=--