From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCHv2 0/6] dm-zoned: improve cache performance Date: Tue, 19 May 2020 10:14:18 +0200 Message-ID: <20200519081424.103318-1-hare@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: Damien LeMoal , dm-devel@redhat.com List-Id: dm-devel.ids Hi all, here's an update to dm-zoned to separate out cache zones. In the update to metadata version 2 the regular drive was split in emulated zones, which were handled just like 'normal' random write zones. This causes a performance drop once these emulated zones have been mapped, as typicall the random zones from the zoned drive will perform noticeably slower than those from the regular drive. (After all, that was kinda the idea of using a regular disk in the first place ...) So in this patchset I've introduced a separate 'cache' zone type, allowing us to differentiate between emulated and real zones. With that we can switch the allocation mode to use only cache zones, and use random zones similar to sequential write zones. That avoids the performance issue noted above. I've also found that the sequential write zones perform noticeably better on writes (which is all we're caching anyway), so I've added another patch switching the allocation routine from preferring sequential write zones for reclaim. This patchset also contains some minor fixes like remving an unused variable etc. As usual, comments and reviews are welcome. Changes to v1: - Include reviews from Damien - Introduce allocation flags - Terminate reclaim on contention - Rework original patch series Hannes Reinecke (6): dm-zoned: return NULL if dmz_get_zone_for_reclaim() fails to find a zone dm-zoned: separate random and cache zones dm-zoned: reclaim random zones when idle dm-zoned: start reclaim with sequential zones dm-zoned: terminate reclaim on congestion dm-zoned: remove unused variable in dmz_do_reclaim() drivers/md/dm-zoned-metadata.c | 140 ++++++++++++++++++++++++++++++----------- drivers/md/dm-zoned-reclaim.c | 109 ++++++++++++++++++++------------ drivers/md/dm-zoned-target.c | 19 ++++-- drivers/md/dm-zoned.h | 13 +++- 4 files changed, 196 insertions(+), 85 deletions(-) -- 2.16.4