RE: [PATCH RFC] liquidio: make timeout HZ independent

[Chickles, Derek]

> -----Original Message-----
> From: Nicholas Mc Guire [mailto:hofrat@xxxxxxxxx]
> Sent: Thursday, December 15, 2016 10:57 PM
> To: Chickles, Derek
> Cc: Burla, Satananda; Manlunas, Felix; Vatsavayi, Raghu;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Nicholas Mc Guire
> Subject: [PATCH RFC] liquidio: make timeout HZ independent
> 
> schedule_timeout_* takes a timeout in jiffies but the code currently is
> passing in a constant which makes this timeout HZ dependent, so pass it
> through msecs_to_jiffies() to fix this up.
> 
> Fixes: commit b0d66369edcd ("liquidio VF error handling")
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
> ---
> 
> Problem found by coccinelle spatch
> 
> The current wait time can vary by a factor 10 depending on the HZ
> setting chose, which does not seem reasonable here.
> 
> The below patch sets the timeout to 100ms - it is though not clear
> if this is the intent or if it should be longer/shorter as it is not
> clear what HZ setting was assumed during design and used for testing.
> 
> This needs an ack by someone who knows the device and can confirm that
> 100ms is reasonable to wait for completion of in-flight requests.

Yes, 100ms was the intent here.

Thanks for catching this.

Derek