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From: Phillip Susi <phill@thesusis.net>
To: Damien Le Moal <damien.lemoal@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org,
	"Martin K . Petersen" <martin.petersen@oracle.com>,
	linux-scsi@vger.kernel.org
Subject: Re: [PATCH v6 0/5] Initial support for multi-actuator HDDs
Date: Fri, 27 Aug 2021 09:58:38 -0400	[thread overview]
Message-ID: <874kbbugtw.fsf@vps.thesusis.net> (raw)
In-Reply-To: <20210827075045.642269-1-damien.lemoal@wdc.com>


Damien Le Moal <damien.lemoal@wdc.com> writes:

> Single LUN multi-actuator hard-disks are cappable to seek and execute
> multiple commands in parallel. This capability is exposed to the host
> using the Concurrent Positioning Ranges VPD page (SCSI) and Log (ATA).
> Each positioning range describes the contiguous set of LBAs that an
> actuator serves.

Are these ranges exlusive to each actuator or can they overlap?

> This series does not attempt in any way to optimize accesses to
> multi-actuator devices (e.g. block IO schedulers or filesystems). This
> initial support only exposes the independent access ranges information
> to user space through sysfs.

Is the plan to eventually change the IO scheduler to maintain two
different queues, one for each actuator, and send down commands for two
different IO streams that the elevator attempts to keep sequential?


  parent reply	other threads:[~2021-08-27 14:09 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-27  7:50 [PATCH v6 0/5] Initial support for multi-actuator HDDs Damien Le Moal
2021-08-27  7:50 ` [PATCH v6 1/5] block: Add independent access ranges support Damien Le Moal
2021-08-27  7:50 ` [PATCH v6 2/5] scsi: sd: add concurrent positioning " Damien Le Moal
2021-08-27  7:50 ` [PATCH v6 3/5] libata: support concurrent positioning ranges log Damien Le Moal
2021-08-27  7:50 ` [PATCH v6 4/5] doc: document sysfs queue/independent_access_ranges attributes Damien Le Moal
2021-08-27  7:50 ` [PATCH v6 5/5] doc: Fix typo in request queue sysfs documentation Damien Le Moal
2021-08-27 13:58 ` Phillip Susi [this message]
2021-08-27 14:28   ` [PATCH v6 0/5] Initial support for multi-actuator HDDs Tim Walker
2021-08-27 16:41     ` Christoph Hellwig
2021-08-27 17:00       ` Tim Walker
2021-08-29 22:55       ` Damien Le Moal
2021-08-27 17:34     ` Phillip Susi
2021-08-29 22:50       ` Damien Le Moal

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