Re: [PATCH V2 3/3] scsi: mptxsas: offload IRQ execution

[Sinan Kaya]

On 11/9/2015 2:15 AM, Hannes Reinecke wrote:
> On 11/09/2015 02:57 AM, Sinan Kaya wrote:
> > The mpt2sas and mpt3sas drivers are spinning forever in
> > their IRQ handlers if there are a lot of jobs queued up
> > by the PCIe card. This handler is causing spikes for
> > the rest of the system and sluggish behavior.
> >
> > Marking all MSI interrupts as non-shared and moving the
> > MSI interrupts to thread context. This relexes the rest
> > of the system execution.
> NACK.
>
> If there is a scalability issue when handling interrupts
> it should be fixed in the driver directly.
>
> Looking at the driver is should be possible to implement
> a worker thread handling the reply descriptor, and having the
> interrupt only to fetch the reply descriptor.

Can you go into the detail about which part of the _base_interrupt 
function needs to be executed in ISR context and which part can be 
queued up to worker thread?

I'm not familiar with the hardware or the code. That's why, I moved the 
entire ISR into the thread context.



> Cheers,
>
> Hannes

--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a 
Linux Foundation Collaborative Project
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