> From: Haiyang Zhang
> Sent: Friday, May 25, 2018 12:52
> To: Dexuan Cui <[email protected]>; Lorenzo Pieralisi
> <[email protected]>; Bjorn Helgaas <[email protected]>;
> [email protected]; KY Srinivasan <[email protected]>; Stephen
> Hemminger <[email protected]>; [email protected];
> [email protected]; [email protected]
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: RE: [PATCH] PCI: hv: Fix a __local_bh_enable_ip warning in
> hv_compose_msi_msg()
> 
> > From: Dexuan Cui
> > Sent: Tuesday, May 22, 2018 8:18 PM
> > To: Lorenzo Pieralisi <[email protected]>; Bjorn Helgaas
> > <[email protected]>; [email protected]; KY Srinivasan
> > <[email protected]>; Stephen Hemminger <[email protected]>;
> > [email protected]; [email protected]; [email protected]
> > Cc: [email protected]; [email protected];
> > Haiyang Zhang <[email protected]>; [email protected];
> > [email protected]
> > Subject: [PATCH] PCI: hv: Fix a __local_bh_enable_ip warning in
> > hv_compose_msi_msg()
> >
> >
> > Commit de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in
> hv_compose_msi_msg()")
> > uses local_bh_disable()/enable(), because hv_pci_onchannelcallback() can
> also
> > run in tasklet context as the channel event callback.
> >
> > With CONFIG_PROVE_LOCKING=y in the latest mainline, or old kernels that
> > don't have commit f71b74bca637 ("irq/softirqs: Use lockdep to assert IRQs
> are
> > disabled/enabled"), it turns out can we trigger a warning at the beginning 
> > of
> > __local_bh_enable_ip(), because the upper layer irq code can call
> > hv_compose_msi_msg() with local irqs disabled.
> >
> > Let's fix the warning by switching to local_irq_save()/restore(). This is 
> > not an
> > issue because hv_pci_onchannelcallback() is not slow, and it not a hot path.
> >
> > Fixes: de0aa7b2f97d ("PCI: hv: Fix 2 hang issues in hv_compose_msi_msg()")
> > Signed-off-by: Dexuan Cui <[email protected]>
> > Cc: <[email protected]>
> > Cc: Stephen Hemminger <[email protected]>
> > Cc: K. Y. Srinivasan <[email protected]>
> > ---
> 
> Reviewed-by: Haiyang Zhang <[email protected]>
> 
> Thanks you.

Hi Lorenzo,

Can I have your reply to this patch?

-- Dexuan
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