RE: [EXT] Re: [PATCH 0/2] qla2xxx - add nvme map_queues support

[Saurav Kashyap <skashyap@marvell.com>]

Hi,

Can I get a review for this patch set?

Thanks,
~Saurav

> -----Original Message-----
> From: Saurav Kashyap <skashyap@marvell.com>
> Sent: Wednesday, August 25, 2021 10:29 AM
> To: Ming Lei <ming.lei@redhat.com>
> Cc: Sagi Grimberg <sagi@grimberg.me>; Nilesh Javali <njavali@marvell.com>;
> martin.petersen@oracle.com; linux-nvme@lists.infradead.org; linux-
> scsi@vger.kernel.org; GR-QLogic-Storage-Upstream <GR-QLogic-Storage-
> Upstream@marvell.com>
> Subject: RE: [EXT] Re: [PATCH 0/2] qla2xxx - add nvme map_queues support
> 
> Hi Ming,
> Comments inline
> 
> > -----Original Message-----
> > From: Ming Lei <ming.lei@redhat.com>
> > Sent: Tuesday, August 24, 2021 9:17 AM
> > To: Saurav Kashyap <skashyap@marvell.com>
> > Cc: Sagi Grimberg <sagi@grimberg.me>; Nilesh Javali <njavali@marvell.com>;
> > martin.petersen@oracle.com; linux-nvme@lists.infradead.org; linux-
> > scsi@vger.kernel.org; GR-QLogic-Storage-Upstream <GR-QLogic-Storage-
> > Upstream@marvell.com>
> > Subject: [EXT] Re: [PATCH 0/2] qla2xxx - add nvme map_queues support
> >
> > External Email
> >
> > ----------------------------------------------------------------------
> > On Tue, Aug 24, 2021 at 03:38:24AM +0000, Saurav Kashyap wrote:
> > > Hi Sagi,
> > > Comments inline
> > >
> > > > -----Original Message-----
> > > > From: Sagi Grimberg <sagi@grimberg.me>
> > > > Sent: Monday, August 23, 2021 10:51 PM
> > > > To: Nilesh Javali <njavali@marvell.com>; martin.petersen@oracle.com;
> > linux-
> > > > nvme@lists.infradead.org; Ming Lei <ming.lei@redhat.com>
> > > > Cc: linux-scsi@vger.kernel.org; GR-QLogic-Storage-Upstream <GR-QLogic-
> > > > Storage-Upstream@marvell.com>
> > > > Subject: Re: [PATCH 0/2] qla2xxx - add nvme map_queues support
> > > >
> > > >
> > > > On 8/23/21 5:56 AM, Nilesh Javali wrote:
> > > > > Currently nvme fc doesn't support map queue functionality. This patch
> > > > > set adds map_queue functionality to nvme_fc_mq_ops and
> > > > > nvme_fc_port_template, providing an option to LLDs to map queues
> > > > > similar to SCSI. For qla2xxx, minimum 10% improvement is noticed
> > > > > with this change as it helps in reducing cpu thrashing.
> > > >
> > > > Does this make nvme-fc use managed irq?
> > >
> > > qla2xxx driver uses pci_alloc_irq_vectors_affinity to have affinity with each
> > MSI-X vector. Currently nvme queue are not mapped based on affinity and irq
> > offset. The change is to use blk_mq_pci_map_queues for mapping, this
> function
> > consider irq affinity as well as irq offset.
> > >
> >
> > OK, got it. Even though without this patchset, nvme-fc actually relies
> > on managed irq since qla2xxx driver uses pci_alloc_irq_vectors_affinity.
> >
> > Now the patchset[1] isn't good for addressing the issue in
> > blk_mq_alloc_request_hctx().
> 
> Can you please elaborate on this? Is there something needs to be done from my
> side?
> 
> Thanks,
> ~Saurav
> >
> > [1] https://urldefense.proofpoint.com/v2/url?u=https-
> > 3A__lore.kernel.org_linux-2Dblock_YR7demOSG6MKFVAF-40T590_T_-
> >
> 23t&d=DwIBAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=ZHZbmY_LbM3DUZK_BDO1
> > OITP3ot_Vkb_5w-
> >
> gas5TBMQ&m=CqFDnfAsZphubKXkUx5gsRF6RZ2Qe6sxWkYq4pBfFD0&s=2Nba
> > EUI5eB6_R6PxW8ld1Xn2OU3_UdD6D30uvFAWhow&e=
> >
> >
> > Thanks,
> > Ming