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From:   Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>
To:     Keith Busch <kbusch@kernel.org>,
        Josh Triplett <josh@joshtriplett.org>
CC:     Jens Axboe <axboe@fb.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Christoph Hellwig <hch@lst.de>,
        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
        Sagi Grimberg <sagi@grimberg.me>
Subject: Re: [PATCH] nvme: Check for readiness more quickly, to speed up boot
 time
Thread-Topic: [PATCH] nvme: Check for readiness more quickly, to speed up boot
 time
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Date:   Sun, 1 Mar 2020 19:53:17 +0000
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Keith,=0A=
=0A=
On 03/01/2020 10:32 AM, Keith Busch wrote:=0A=
> The key being this sleep schedules the task unlike udelay. It's neat=0A=
> you can boot where 100ms is considered a long time.=0A=
>=0A=
> This clearly helps when you've one nvme that becomes ready quickly, but=
=0A=
> what happens with many nvme's that are slow to ready? This change will=0A=
> end up polling the status of those 1000's of times, I wonder if there's=
=0A=
> a point where this frequent sleep/wake cycle initializing a whole lot=0A=
> of nvme devices in parallel may interfere with other init tasks.=0A=
=0A=
This is what I didn't understand, although patch does improves=0A=
performance for one controller under one situation, (also after=0A=
testing I didn't see big issues with the controllers that I've,=0A=
I didn't understand how it will behave with the situation you have=0A=
mentioned. But anyways, looks good.=0A=
=0A=
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>=0A=