From: Bjorn Helgaas <helgaas@kernel.org>
To: Logan Gunthorpe <logang@deltatee.com>
Cc: linux-kernel@vger.kernel.org, linux-ntb@googlegroups.com,
linux-pci@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kselftest@vger.kernel.org, Jon Mason <jdmason@kudzu.us>,
Joerg Roedel <joro@8bytes.org>, Allen Hubbe <allenbh@gmail.com>,
Dave Jiang <dave.jiang@intel.com>,
Serge Semin <fancer.lancer@gmail.com>,
Eric Pilmore <epilmore@gigaio.com>
Subject: Re: [PATCH v3 09/10] NTB: Add MSI interrupt support to ntb_transport
Date: Fri, 22 Mar 2019 11:47:43 -0500 [thread overview]
Message-ID: <20190322164743.GN251185@google.com> (raw)
In-Reply-To: <20190322000645.15580-10-logang@deltatee.com>
Hi Logan,
Drive-by nits:
On Thu, Mar 21, 2019 at 06:06:44PM -0600, Logan Gunthorpe wrote:
> Introduce the module parameter 'use_msi' which, when set uses
s/set/set,/
> MSI interrupts instead of doorbells for each queue pair (QP). T
> he parameter is only available if NTB MSI support is configured into
Spurious newline in the middle of "The".
> the kernel. We also require there to be more than one memory window
> (MW) so that an extra one is available to forward the APIC region.
>
> To use MSIs, we request one interrupt per QP and forward the MSI address
> and data to the peer using scratch pad registers (SPADS) above the MW
> spads. (If there are not enough SPADS the MSI interrupt will not be used.)
/spads/SPADS/ for consistency
> Once registered, we simply use ntb_msi_peer_trigger and the recieving
s/recieving/receiving/
> ISR simply queues up the rxc_db_work for the queue.
>
> This addition can significantly improve performance of ntb_transport.
> In a simple, untuned, apples-to-apples comparision using ntb_netdev
> and iperf with switchtec hardware, I see 3.88Gb/s without MSI
> interrupts and 14.1Gb/s which is a more than 3x improvement.
s/which is/with MSI, which is/
Bjorn
WARNING: multiple messages have this Message-ID (diff)
From: helgaas at kernel.org (Bjorn Helgaas)
Subject: [PATCH v3 09/10] NTB: Add MSI interrupt support to ntb_transport
Date: Fri, 22 Mar 2019 11:47:43 -0500 [thread overview]
Message-ID: <20190322164743.GN251185@google.com> (raw)
In-Reply-To: <20190322000645.15580-10-logang@deltatee.com>
Hi Logan,
Drive-by nits:
On Thu, Mar 21, 2019 at 06:06:44PM -0600, Logan Gunthorpe wrote:
> Introduce the module parameter 'use_msi' which, when set uses
s/set/set,/
> MSI interrupts instead of doorbells for each queue pair (QP). T
> he parameter is only available if NTB MSI support is configured into
Spurious newline in the middle of "The".
> the kernel. We also require there to be more than one memory window
> (MW) so that an extra one is available to forward the APIC region.
>
> To use MSIs, we request one interrupt per QP and forward the MSI address
> and data to the peer using scratch pad registers (SPADS) above the MW
> spads. (If there are not enough SPADS the MSI interrupt will not be used.)
/spads/SPADS/ for consistency
> Once registered, we simply use ntb_msi_peer_trigger and the recieving
s/recieving/receiving/
> ISR simply queues up the rxc_db_work for the queue.
>
> This addition can significantly improve performance of ntb_transport.
> In a simple, untuned, apples-to-apples comparision using ntb_netdev
> and iperf with switchtec hardware, I see 3.88Gb/s without MSI
> interrupts and 14.1Gb/s which is a more than 3x improvement.
s/which is/with MSI, which is/
Bjorn
WARNING: multiple messages have this Message-ID (diff)
From: helgaas@kernel.org (Bjorn Helgaas)
Subject: [PATCH v3 09/10] NTB: Add MSI interrupt support to ntb_transport
Date: Fri, 22 Mar 2019 11:47:43 -0500 [thread overview]
Message-ID: <20190322164743.GN251185@google.com> (raw)
Message-ID: <20190322164743.VFZOU_AxR2H6HKWuNMuAir8l38YokasZfJ0uzckZlE4@z> (raw)
In-Reply-To: <20190322000645.15580-10-logang@deltatee.com>
Hi Logan,
Drive-by nits:
On Thu, Mar 21, 2019@06:06:44PM -0600, Logan Gunthorpe wrote:
> Introduce the module parameter 'use_msi' which, when set uses
s/set/set,/
> MSI interrupts instead of doorbells for each queue pair (QP). T
> he parameter is only available if NTB MSI support is configured into
Spurious newline in the middle of "The".
> the kernel. We also require there to be more than one memory window
> (MW) so that an extra one is available to forward the APIC region.
>
> To use MSIs, we request one interrupt per QP and forward the MSI address
> and data to the peer using scratch pad registers (SPADS) above the MW
> spads. (If there are not enough SPADS the MSI interrupt will not be used.)
/spads/SPADS/ for consistency
> Once registered, we simply use ntb_msi_peer_trigger and the recieving
s/recieving/receiving/
> ISR simply queues up the rxc_db_work for the queue.
>
> This addition can significantly improve performance of ntb_transport.
> In a simple, untuned, apples-to-apples comparision using ntb_netdev
> and iperf with switchtec hardware, I see 3.88Gb/s without MSI
> interrupts and 14.1Gb/s which is a more than 3x improvement.
s/which is/with MSI, which is/
Bjorn
next prev parent reply other threads:[~2019-03-22 16:47 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-22 0:06 [PATCH v3 00/10] Support using MSI interrupts in ntb_transport Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 01/10] PCI/MSI: Support allocating virtual MSI interrupts Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 02/10] PCI/switchtec: Add module parameter to request more interrupts Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 03/10] NTB: Introduce helper functions to calculate logical port number Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 16:51 ` Bjorn Helgaas
2019-03-22 16:51 ` Bjorn Helgaas
2019-03-22 16:51 ` helgaas
2019-03-22 0:06 ` [PATCH v3 04/10] NTB: Introduce functions to calculate multi-port resource index Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 05/10] NTB: Rename ntb.c to support multiple source files in the module Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 06/10] NTB: Introduce MSI library Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 07/10] NTB: Introduce NTB MSI Test Client Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 08/10] NTB: Add ntb_msi_test support to ntb_test Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 0:06 ` [PATCH v3 09/10] NTB: Add MSI interrupt support to ntb_transport Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
2019-03-22 16:47 ` Bjorn Helgaas [this message]
2019-03-22 16:47 ` Bjorn Helgaas
2019-03-22 16:47 ` helgaas
2019-03-25 19:08 ` Logan Gunthorpe
2019-03-25 19:08 ` Logan Gunthorpe
2019-03-25 19:08 ` Logan Gunthorpe
2019-03-25 19:08 ` logang
2019-03-22 0:06 ` [PATCH v3 10/10] NTB: Describe the ntb_msi_test client in the documentation Logan Gunthorpe
2019-03-22 0:06 ` Logan Gunthorpe
2019-03-22 0:06 ` logang
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