On Tuesday 21 May 2013 13:43, Or Gerlitz wrote:
> On 21/05/2013 13:42, Bart Van Assche wrote:
> > On 05/21/13 11:40, Or Gerlitz wrote:
> >> 2. is possible in the Linux kernel for one hard irq callback to flash on
> >> CPU X while another hard irq callback is running on the same CPU?
> >
> > I think that from kernel 2.6.35 on MSI IRQs are no longer nested. See
> > also
> > http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=753649dbc49345a73a2454c770a3f2d54d11aec6
> >
> > or http://lwn.net/Articles/380931/
>
> thanks, so suppose we agree on that, still the patch makes sense as the
> race is there, but does the patch has to change?
>
> Or.
>
I just need to verify that the patch can be applied correctly on the upstream
kernel.
The use of RCU (and not spinlock) makes sense from a performance standpoint
in any case. We do NOT want to force mlx4_cq_completion to have a spinlock
which is device-global, resulting in having completion event processing be
single-threaded in effect).
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
