Re: [Libevent-users] Strange timeout scheduling in 1.4

2011-08-04 Thread Ralph Castain
Frankly, having fought the test vs user-configure battle many times, there comes a point where the user bears some responsibility. This strikes me as one of those times. For us, at least, creating another startup delay while libevent probes timers would be more than annoying. It is completely r

Re: [Libevent-users] Strange timeout scheduling in 1.4

2011-08-04 Thread Jardel Weyrich
The problem I see is that you can't assume system A would be faster with timing mechanism X, or system B with timing mechanism Z. This may vary from device to device. I believe this is not something that can be reliably solved without querying the actual system at runtime. See a) http://docs.redha

Re: [Libevent-users] Strange timeout scheduling in 1.4

2011-08-04 Thread Dave Hart
On Thu, Aug 4, 2011 at 18:36 UTC, Nick Mathewson wrote: > Hmmm. So as near as I can tell, coming out of this whole discussion, I > can see a few options for Libevent 2.1: > > * Make no changes in the code, but suggest to people that they should > be using EVENT_BASE_FLAG_NO_CACHE_TIME if they are

Re: [Libevent-users] Strange timeout scheduling in 1.4

2011-08-04 Thread Nick Mathewson
On Thu, Jul 28, 2011 at 11:32 AM, Leonid Evdokimov wrote: > Also, FYI, I tried to use event_base_init_common_timeout with trivial > timeout callback and got following numbers: > > 18% of single CPU core usage with 65536 250ms persistent timeouts > 7% of single CPU core usage with 65536 250ms persi

Re: [Libevent-users] Strange timeout scheduling in 1.4

2011-08-04 Thread Nick Mathewson
On Thu, Jul 28, 2011 at 3:35 AM, Nicholas Marriott wrote: > Interesting. > > We have seen problems in the past with gettimeofday() not being very > deterministic on Linux, with occasional spikes in the time it takes, > although I don't have the numbers to hand (50-100 microseconds or so are > the