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

Re: [Xen-devel] DomU's network interface will hung when Dom0 running 32bit




On 2013-10-15 20:58, Wei Liu wrote:
On Tue, Oct 15, 2013 at 07:26:31PM +0800, jianhai luan wrote:
[...]
Can you propose a patch?
Because credit_timeout.expire always after jiffies, i judge the
value over the range of time_after_eq() by time_before(now,
vif->credit_timeout.expires). please check the patch.
I don't think this really fix the issue for you. You still have chance
that now wraps around and falls between expires and next_credit. In that
case it's stalled again.
if time_before(now, vif->credit_timeout.expires) is true, time wrap
and do operation. Otherwise time_before(now,
vif->credit_timeout.expires) isn't true, now -
vif->credit_timeout.expires should be letter than ULONG_MAX/2.
Because next_credit large than vif->credit_timeout.expires
(next_crdit = vif->credit_timeout.expires +
msecs_to_jiffies(vif->credit_usec/1000)), the delta between now and
next_credit should be in range of time_after_eq().  So
time_after_eq() do correctly judge.

Not sure I understand you. Consider "now" is placed like this:

    expires   now   next_credit
    ----time increases this direction--->

* time_after_eq(now, next_credit) -> false
* time_before(now, expires) -> false

If now is placed in above environment, the result will be correct (Sending package will be not allowed until next_credit).
* time_after_eq(now, next_credit)  --> false will include two environment:
  expires     now   next_credit
  -----------time increases this direction ---->

Or
  expires      next_credit             next_credit + MAX_LONG/2 now
  -----------time increases this direction ---->


the first environment should be correct to control transmit. the second environment is our included environment.

Jason

Then it's stuck again. You're merely narrowing the window, not fixing
the real problem.

Wei.

Jason
Wei.


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.