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From: Keith Busch <keith.busch@intel.com>
To: Wenbo Wang <wenbo.wang@memblaze.com>
Cc: Jens Axboe <axboe@fb.com>, Wenbo Wang <mail_weber_wang@163.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
	"Wenwei.Tao" <wenwei.tao@memblaze.com>
Subject: Re: [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended
Date: Tue, 9 Feb 2016 22:55:49 +0000	[thread overview]
Message-ID: <20160209225548.GA32064@localhost.localdomain> (raw)
In-Reply-To: <BJXPR01MB199E172F7B186281D1C7179E0D60@BJXPR01MB199.CHNPR01.prod.partner.outlook.cn>

On Tue, Feb 09, 2016 at 11:22:04AM +0000, Wenbo Wang wrote:
> In most cases, rcu read lock is just a preempt_disable, which is what get_cpu does. I don't see any risk.

Yes, many rcu_read_lock cases expand similarly to get_cpu. What about
the other cases?

FWIW, I don't think we'll hit the problem with the proposed rcu sync.
Heck, we don't even have a synchronize today and we don't hit the
theoretical problem.

WARNING: multiple messages have this Message-ID (diff)
From: keith.busch@intel.com (Keith Busch)
Subject: [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended
Date: Tue, 9 Feb 2016 22:55:49 +0000	[thread overview]
Message-ID: <20160209225548.GA32064@localhost.localdomain> (raw)
In-Reply-To: <BJXPR01MB199E172F7B186281D1C7179E0D60@BJXPR01MB199.CHNPR01.prod.partner.outlook.cn>

On Tue, Feb 09, 2016@11:22:04AM +0000, Wenbo Wang wrote:
> In most cases, rcu read lock is just a preempt_disable, which is what get_cpu does. I don't see any risk.

Yes, many rcu_read_lock cases expand similarly to get_cpu. What about
the other cases?

FWIW, I don't think we'll hit the problem with the proposed rcu sync.
Heck, we don't even have a synchronize today and we don't hit the
theoretical problem.

  reply	other threads:[~2016-02-09 22:55 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-01 15:42 [PATCH] NVMe: do not touch sq door bell if nvmeq has been suspended Wenbo Wang
2016-02-01 15:42 ` Wenbo Wang
2016-02-01 15:59 ` Busch, Keith
2016-02-01 15:59   ` Busch, Keith
2016-02-01 16:17   ` Wenbo Wang
2016-02-01 16:17     ` Wenbo Wang
2016-02-01 16:54 ` Jens Axboe
2016-02-01 16:54   ` Jens Axboe
2016-02-02  7:15   ` Wenbo Wang
2016-02-02 12:41     ` Sagi Grimberg
2016-02-02 12:41       ` Sagi Grimberg
2016-02-02 14:27       ` Keith Busch
2016-02-02 14:27         ` Keith Busch
2016-02-02 14:33         ` Sagi Grimberg
2016-02-02 14:33           ` Sagi Grimberg
2016-02-02 14:46           ` Keith Busch
2016-02-02 14:46             ` Keith Busch
2016-02-02 17:20             ` Sagi Grimberg
2016-02-02 17:20               ` Sagi Grimberg
2016-02-03  0:49               ` Wenbo Wang
2016-02-02 17:25     ` Keith Busch
2016-02-02 17:25       ` Keith Busch
2016-02-03  0:19       ` Wenbo Wang
2016-02-03 14:41     ` Keith Busch
2016-02-03 14:41       ` Keith Busch
2016-02-03 16:35       ` Wenbo Wang
2016-02-03 16:38         ` Keith Busch
2016-02-03 16:38           ` Keith Busch
2016-02-06 14:32           ` Wenbo Wang
2016-02-07 13:41             ` Sagi Grimberg
2016-02-07 13:41               ` Sagi Grimberg
2016-02-08 15:01             ` Keith Busch
2016-02-08 15:01               ` Keith Busch
2016-02-09 11:22               ` Wenbo Wang
2016-02-09 22:55                 ` Keith Busch [this message]
2016-02-09 22:55                   ` Keith Busch

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