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From: John Garry <john.garry@huawei.com>
To: "Melanie Plageman (Microsoft)" <melanieplageman@gmail.com>,
	<mikelley@microsoft.com>, <jejb@linux.ibm.com>,
	<kys@microsoft.com>, <martin.petersen@oracle.com>,
	<mst@redhat.com>, <benh@kernel.crashing.org>,
	<decui@microsoft.com>, <don.brace@microchip.com>,
	<R-QLogic-Storage-Upstream@marvell.com>, <haiyangz@microsoft.com>,
	<jasowang@redhat.com>, <kashyap.desai@broadcom.com>,
	<mpe@ellerman.id.au>, <njavali@marvell.com>,
	<pbonzini@redhat.com>, <paulus@samba.org>,
	<sathya.prakash@broadcom.com>,
	<shivasharan.srikanteshwara@broadcom.com>,
	<sreekanth.reddy@broadcom.com>, <stefanha@redhat.com>,
	<sthemmin@microsoft.com>, <suganath-prabu.subramani@broadcom.com>,
	<sumit.saxena@broadcom.com>, <tyreld@linux.ibm.com>,
	<wei.liu@kernel.org>, <linuxppc-dev@lists.ozlabs.org>,
	<megaraidlinux.pdl@broadcom.com>,
	<mpi3mr-linuxdrv.pdl@broadcom.com>, <storagedev@microchip.com>,
	<virtualization@lists.linux-foundation.org>,
	<linux-hyperv@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-scsi@vger.kernel.org>, <MPT-FusionLinux.pdl@broadcom.com>
Cc: andres@anarazel.de
Subject: Re: [PATCH RFC v1 0/5] Add SCSI per device tagsets
Date: Mon, 21 Feb 2022 17:40:23 +0000	[thread overview]
Message-ID: <9e7925d6-067c-0b3a-a788-f036272496e6@huawei.com> (raw)
In-Reply-To: <20220218184157.176457-1-melanieplageman@gmail.com>

On 18/02/2022 18:41, Melanie Plageman (Microsoft) wrote:
> For example: a device provisioned with high IOPS and BW limits on the same
> controller as a smaller and slower device can starve the slower device of tags.
> This is especially noticeable when the slower device's workload has low I/O
> depth tasks.

If you check hctx_may_queue() in the block code then it is noticeable 
that a fair allocation of HW queue depth is allocated per request queue 
to ensure we don't get starvation.

Thanks,
John

      parent reply	other threads:[~2022-02-21 17:58 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-18 18:41 [PATCH RFC v1 0/5] Add SCSI per device tagsets Melanie Plageman (Microsoft)
2022-02-18 18:41 ` [PATCH RFC v1 1/5] scsi: core: Rename host_tagset to hctx_share_tags Melanie Plageman (Microsoft)
2022-02-18 18:41 ` [PATCH RFC v1 2/5] scsi: map_queues() takes tag set instead of host Melanie Plageman (Microsoft)
2022-02-18 18:41 ` [PATCH RFC v1 3/5] scsi: core: Add per device tag sets Melanie Plageman (Microsoft)
2022-02-18 18:41 ` [PATCH RFC v1 4/5] scsi: storvsc: use " Melanie Plageman (Microsoft)
2022-02-18 18:41 ` [PATCH RFC v1 5/5] scsi: storvsc: Hardware queues share blk_mq_tags Melanie Plageman (Microsoft)
2022-02-19  7:37 ` [PATCH RFC v1 0/5] Add SCSI per device tagsets Christoph Hellwig
2022-02-21 17:40 ` John Garry [this message]

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