Re: [PATCH v3 2/6] PM / Runtime: introduce pm_runtime_set[get]_memalloc_noio()

[Alan Stern]

On Wed, 31 Oct 2012, Alan Stern wrote:

> On Wed, 31 Oct 2012, Ming Lei wrote:
> 
> > The below idea may help the problem which 'memalloc_noio' flag isn't set during
> > usb_reset_device().
> > 
> > - for usb mass storage device, call pm_runtime_set_memalloc_noio(true)
> >   inside usb_stor_probe2() and uas_probe(), and call
> >   pm_runtime_set_memalloc_noio(false) inside uas_disconnect()
> >   and usb_stor_disconnect().
> 
> Why would you want to do that?  The probe and disconnect routines
> usually -- but not always -- run in the khubd thread.  Surely you don't
> want to prevent khubd from using GFP_KERNEL?
> 
> And what if probe runs in khubd but disconnect runs in a different 
> thread?

Sorry, I misread your message.  You are setting the device's flag, not 
the thread's flag.

This still doesn't help in this case where CONFIG_PM_RUNTIME is 
disabled.  I think it will be simpler to set the noio flag during every 
device reset.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/