From: Sagi Grimberg <sagi@grimberg.me>
To: Hannes Reinecke <hare@suse.de>
Cc: linux-nvme@lists.infradead.org, Christoph Hellwig <hch@lst.de>,
Keith Busch <kbusch@kernel.org>,
Chaitanya Kulkarni <kch@nvidia.com>,
Daniel Wagner <dwagner@suse.de>,
Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Subject: Re: [PATCH 4/6] nvme-mpath: support controller crd when failing over request
Date: Mon, 24 Aug 2026 15:23:59 +0100 [thread overview]
Message-ID: <aoxT_wwbT93Cv5F5@casper.infradead.org> (raw)
In-Reply-To: <c3ca9481-8eaa-496b-bdde-38cd911d8f96@suse.de>
> > + /* no CRD or timer allocation failed, fallback to immediate failover */
> > + if (!fot) {
> > + spin_lock_irqsave(&ns->head->requeue_lock, flags);
> > + blk_steal_bios(&ns->head->requeue_list, req);
> > + spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
> > + kblockd_schedule_work(&ns->head->requeue_work);
> > + }
>
> Yikes. Allocation during failover is not going to make you friends.
Well, it is a fairly rare event, and the fallback is exactly what we
do today...
>
> And this whole mechanism looks pretty similar what we did over at
> implementing CCR. Can you use the mechanism from there?
How is this similar? It is effectively creating a container for
bio_list and timer to requeue them when the timer expires...
next prev parent reply other threads:[~2026-08-24 14:24 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-23 8:48 [PATCH 0/6] Support per command retry timer Sagi Grimberg
2026-08-23 8:48 ` [PATCH 1/6] nvme-mpath: No need to protect req->bio with requeue_lock Sagi Grimberg
2026-08-24 11:31 ` Hannes Reinecke
2026-08-24 15:53 ` John Garry
2026-09-02 13:39 ` Christoph Hellwig
2026-08-23 8:48 ` [PATCH 2/6] nvme: add nvme_crd_msecs helper Sagi Grimberg
2026-08-24 11:32 ` Hannes Reinecke
2026-09-02 13:40 ` Christoph Hellwig
2026-09-06 0:07 ` Sagi Grimberg
2026-08-23 8:48 ` [PATCH 3/6] nvme: add per request retry timer Sagi Grimberg
2026-08-24 13:25 ` Hannes Reinecke
2026-09-02 13:41 ` Christoph Hellwig
2026-09-06 0:09 ` Sagi Grimberg
2026-09-11 22:53 ` Sagi Grimberg
2026-08-23 8:49 ` [PATCH 4/6] nvme-mpath: support controller crd when failing over request Sagi Grimberg
2026-08-24 13:45 ` Hannes Reinecke
2026-08-24 14:23 ` Sagi Grimberg [this message]
2026-09-02 13:43 ` Christoph Hellwig
2026-09-06 0:15 ` Sagi Grimberg
2026-08-23 8:49 ` [PATCH 5/6] nvmet: Add support for configurable crdt (command retry delay) attributes Sagi Grimberg
2026-09-02 13:44 ` Christoph Hellwig
2026-09-06 0:20 ` Sagi Grimberg
2026-08-23 8:49 ` [PATCH 6/6] nvme/fault-injection: Support for error injection with custom crd Sagi Grimberg
2026-08-23 8:49 ` [PATCH 7/6 RFC] nvme: test per-command retry delay Sagi Grimberg
2026-08-30 8:23 ` Shin'ichiro Kawasaki
2026-08-30 20:55 ` Sagi Grimberg
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