From: Jens Axboe <axboe@kernel.dk>
To: yang jun <yangjun.donglife123@gmail.com>
Cc: "linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: [SCSI] sr: sr_mutex ,multi-drive performance is bad
Date: Tue, 29 Oct 2013 08:53:58 -0600 [thread overview]
Message-ID: <526FCC06.6070908@kernel.dk> (raw)
In-Reply-To: <CAO4Pk4wxUN-O_m5KcdZgmTTRG2w8icqva+0dxu7HRO=rEpbArg@mail.gmail.com>
On 10/28/2013 08:30 AM, yang jun wrote:
> Dear Mr.Axboe,
>
> The latest kernel sr_module still uses single mutex,it will serialise
> all sr ioctls. Otto Meta had mentioned this on Jan 1st, 2013 . Some
> record tools such as growisofs use SG_IO to write data to disc, so if
> there are multiple cdroms being recorded at the same time，it will be
> very slowly.
>
> I saw sd_module before,it had removed BKL and made "openers" atomic_t
> in scsi_disk. Shall we do the same thing to sr_module? That is, to
> remove sr_mutex and make "use_count" atomic_t in cdrom_device_info.
The same conversion that happened to sd could apply to sr just as easily.
--
Jens Axboe
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next prev parent reply other threads:[~2013-10-29 14:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-28 14:30 [SCSI] sr: sr_mutex ,multi-drive performance is bad yang jun
2013-10-29 14:06 ` yang jun
2013-10-29 14:08 ` yang jun
2013-10-29 14:53 ` Jens Axboe [this message]
2013-10-30 15:13 ` yang jun
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