From: Ming Lei <ming.lei@redhat.com>
To: Christoph Hellwig <hch@lst.de>
Cc: "Jens Axboe" <axboe@kernel.dk>,
linux-block@vger.kernel.org, "Nilay Shroff" <nilay@linux.ibm.com>,
"Shinichiro Kawasaki" <shinichiro.kawasaki@wdc.com>,
"Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Subject: Re: [PATCH 05/15] block: simplify elevator reset for updating nr_hw_queues
Date: Tue, 15 Apr 2025 10:05:16 +0800 [thread overview]
Message-ID: <Z_2-3AhBRcYtkWWN@fedora> (raw)
In-Reply-To: <20250414060959.GB6451@lst.de>
On Mon, Apr 14, 2025 at 08:09:59AM +0200, Christoph Hellwig wrote:
> On Mon, Apr 14, 2025 at 08:58:28AM +0800, Ming Lei wrote:
> > > Coming back to this after looking through the next patches.
> > >
> > > Why do we even need the __elevator_change call here? We've not
> > > actually disabled the elevator, and we prevent other callers
> > > from changing it.
> > >
> > > As you pass in the force argument this now always calls
> > > elevator_switch and thus blk_mq_init_sched. But why?
> >
> > sched tags is built over hctx and depends on ->nr_hw_queues,
> > when nr_hw_queues is changed, sched tags has to be rebuilt.
>
> Can you add a comment explaining this?
Sure.
Thanks,
Ming
next prev parent reply other threads:[~2025-04-15 2:05 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-10 13:30 [PATCH 00/15] block: unify elevator changing and fix lockdep warning Ming Lei
2025-04-10 13:30 ` [PATCH 01/15] block: don't call freeze queue in elevator_switch() and elevator_disable() Ming Lei
2025-04-10 13:30 ` [PATCH 02/15] block: add two helpers for registering/un-registering sched debugfs Ming Lei
2025-04-10 14:25 ` Christoph Hellwig
2025-04-10 13:30 ` [PATCH 03/15] block: move sched debugfs register into elvevator_register_queue Ming Lei
2025-04-10 14:27 ` Christoph Hellwig
2025-04-14 0:42 ` Ming Lei
2025-04-10 13:30 ` [PATCH 04/15] block: prevent elevator switch during updating nr_hw_queues Ming Lei
2025-04-10 14:36 ` Christoph Hellwig
2025-04-14 0:54 ` Ming Lei
2025-04-14 6:07 ` Christoph Hellwig
2025-04-15 2:03 ` Ming Lei
2025-04-11 19:13 ` Nilay Shroff
2025-04-14 0:55 ` Ming Lei
2025-04-10 13:30 ` [PATCH 05/15] block: simplify elevator reset for " Ming Lei
2025-04-10 14:40 ` Christoph Hellwig
2025-04-10 15:34 ` Christoph Hellwig
2025-04-14 0:58 ` Ming Lei
2025-04-14 6:09 ` Christoph Hellwig
2025-04-15 2:05 ` Ming Lei [this message]
2025-04-10 13:30 ` [PATCH 06/15] block: add helper of elevator_change() Ming Lei
2025-04-10 13:30 ` [PATCH 07/15] block: move blk_unregister_queue() & device_del() after freeze wait Ming Lei
2025-04-14 6:19 ` Christoph Hellwig
2025-04-15 2:26 ` Ming Lei
2025-04-10 13:30 ` [PATCH 08/15] block: add `struct elev_change_ctx` for unifying elevator change Ming Lei
2025-04-14 6:21 ` Christoph Hellwig
2025-04-10 13:30 ` [PATCH 09/15] block: " Ming Lei
2025-04-10 18:37 ` Nilay Shroff
2025-04-14 1:22 ` Ming Lei
2025-04-15 12:30 ` Nilay Shroff
2025-04-16 1:49 ` Ming Lei
2025-04-10 13:30 ` [PATCH 10/15] block: pass elevator_queue to elv_register_queue & unregister_queue Ming Lei
2025-04-14 6:22 ` Christoph Hellwig
2025-04-15 2:31 ` Ming Lei
2025-04-16 4:53 ` Christoph Hellwig
2025-04-10 13:30 ` [PATCH 11/15] block: move elv_register[unregister]_queue out of elevator_lock Ming Lei
2025-04-11 19:20 ` Nilay Shroff
2025-04-14 1:24 ` Ming Lei
2025-04-15 9:39 ` Nilay Shroff
2025-04-15 10:32 ` Ming Lei
2025-04-10 13:30 ` [PATCH 12/15] block: move debugfs/sysfs register out of freezing queue Ming Lei
2025-04-10 18:57 ` Nilay Shroff
2025-04-14 1:42 ` Ming Lei
2025-04-15 9:37 ` Nilay Shroff
2025-04-15 10:06 ` Ming Lei
2025-04-15 11:15 ` Nilay Shroff
2025-04-15 11:54 ` Ming Lei
2025-04-15 12:21 ` Nilay Shroff
2025-04-15 12:41 ` Ming Lei
2025-04-10 13:30 ` [PATCH 13/15] block: remove several ->elevator_lock Ming Lei
2025-04-10 19:07 ` Nilay Shroff
2025-04-14 1:46 ` Ming Lei
2025-04-10 13:30 ` [PATCH 14/15] block: move hctx cpuhp add/del out of queue freezing Ming Lei
2025-04-10 13:30 ` [PATCH 15/15] block: move wbt_enable_default() out of queue freezing from scheduler's ->exit() Ming Lei
2025-04-10 19:20 ` Nilay Shroff
2025-04-14 1:55 ` Ming Lei
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