Re: rndis gadget: Inconsistent locking

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

 



Le mercredi 12 janvier 2011 Ã 13:23 +0000, Jarek Poplawski a Ãcrit :
> On Wed, Jan 12, 2011 at 02:07:12PM +0100, Eric Dumazet wrote:
> ...
> > 
> > Hmm... 
> > 
> > So all net devices in gen_ndis_query_resp() should have a
> > ndo_get_stats() or ndo_get_stats64() method, not allowed to use
> > spin_lock_bh() / spin_unlock_bh()
> > 
> > If yes, we should add big fat comments to pn_net_stats()/eth_get_stats() so that nobody
> > tries to revert your patch ;)
> 
> I'm not sure I got your point: my patch could be replaced with
> ndo_get_stats64() implementing irq safe locking or by changing
> gen_ndis_query_resp() calling context. It's intended as a fast
> (compatible) fix.

I was mentioning that we tried in past months to remove useless
ndo_get_stats() methods that were only doing :

return &net->stats;

random commit : b27d50a9ff5cf2775b7a4daf5

Another possibility would be to use u64_stats_sync.h for these txq
counters.

(no locking needed to read counters, only a seqcount fetch/retry)

As a bonus, no overhead on 64bit arches.


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


[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux