[dpdk-dev] [memnic PATCH] linux: fix race condition
Thomas Monjalon
thomas.monjalon at 6wind.com
Fri Apr 11 17:47:01 CEST 2014
2014-04-11 11:41, Olivier MATZ:
> On Thursday, April 03, 2014 07:35:50 AM Hiroshi Shimamoto wrote:
> > From: Hiroshi Shimamoto <h-shimamoto at ct.jp.nec.com>
> >
> > Same as PMD, there is a race condition between host and guest
> > in the guest MEMNIC kernel driver.
> >
> > Guest PMD Host
> > Thread-A Thread-B vSwitch
> >
> > |idx=0 |idx=0 |p[0] st!=2
> > |cmpxchg | |
> > |p[0] st->1 | |
> > |idx=1 | |
> > |fill data | |
> > |p[0] st->2 | |p[0] st==2
> > |
> > | | |receive data
> > | | |p[0] st->0
> > | |
> > | |cmpxchg |
> > | |success |p[1] st!=2
> > | |p[0] st->1 |
> > | |
> > This is BAD
> >
> > Signed-off-by: Hiroshi Shimamoto <h-shimamoto at ct.jp.nec.com>
> > ---
> >
> > linux/memnic_net.c | 9 +++++++++
> > 1 file changed, 9 insertions(+)
>
> Reviewed-by: Olivier Matz <olivier.matz at 6wind.com>
Applied
Thanks
--
Thomas
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