Re: [PATCH] b44: add 64 bit stats

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



	Hello,

On Sat, 21 Jul 2012, Eric Dumazet wrote:

> The writer sides might be run concurrently by several cpus, so
> u64_stats_update_begin(&sstats->syncp); are racy : a reader can
> be trapped forever.
> 
> > net/netfilter/ipvs/ip_vs_est.c
> > 
> 
> Same problem for this one, I think.
> 
> I CCed ipvs maintainers so that they can take a look.

	IPVS moved to percpu counters, i.e. even on 32-bit SMP
we do not use locks to protect the seqcounter:

commit b17fc9963f837ef1acfe36e193108fb16ed58647
Author: Hans Schillstrom <hans.schillstrom@xxxxxxxxxxxx>
Date:   Mon Jan 3 14:44:56 2011 +0100

    IPVS: netns, ip_vs_stats and its procfs

> > Do these need to be updated as well?  Looking at these files quickly
> > and with my limited knowledge of the kernel I am not sure if they
> > update the stats in a BH context or not.

	We have 2 kinds of readers:

- timer context (ip_vs_est.c): no _bh is used for fetch
- user context (ip_vs_ctl.c): _bh is used for fetch

> > Kevin
> 
> Thanks !

Regards

--
Julian Anastasov <ja@xxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe lvs-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Filesystem Devel]     [Linux NFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]     [X.Org]

  Powered by Linux