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

From: Sinan Kaya
Date: Tue Nov 10 2015 - 01:00:56 EST

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.


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.



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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