Date: Mon, 26 Sep 2011 23:30:27 +0800 From: Adrian Chadd <adrian@freebsd.org> To: John Baldwin <jhb@freebsd.org> Cc: Alexander Motin <mav@freebsd.org>, freebsd-current@freebsd.org Subject: Re: ath / 802.11n performance issues and timer code Message-ID: <CAJ-VmomyMQpcpHo4ve-_O67_8VVJW-YRqWeb-7exSxzV5rz_pA@mail.gmail.com> In-Reply-To: <201109261053.30410.jhb@freebsd.org> References: <CAJ-VmomZyDJV62yCQOvG=UB6H4wfz9=3_cWzEL7vWAA14TCyYA@mail.gmail.com> <201109260917.44236.jhb@freebsd.org> <CAJ-Vmom721ndMmSihA=58Fux-JBWHo1rA82FXYa__mmaRMW=tQ@mail.gmail.com> <201109261053.30410.jhb@freebsd.org>
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On 26 September 2011 22:53, John Baldwin <jhb@freebsd.org> wrote: > I meant do the timer settings affect UDP performance? =A0I.e. does idleti= ck=3D1 > change UDP performance at all? I'll check that and get back to you. But please keep in mind that the first time I tried this and saw immediate results was with the device in hostap mode - where ethernet and wlan0 are bridged via if_bridge. There's no TCP or UDP state being handled at all. >> Which should wake up a/the taskqueue thread in question and have it >> immediately run the next task on the queue. The taskqueue doesn't have >> any form of timer/callout; it's just a "submit this to get run." When >> will it be run? I hope not at the next tick, not if the CPU is free. > > No, that scheduling is synchronous. =A0Anytime a thread is scheduled the > scheduler will check if it should preempt the current thread to run the > new thread. I admit I don't quite understand yet the scheduler and event/timer handling code. What about if nothing is currently scheduled and the CPU is idle? When will the idle process get tickled? I assume it would preempt the idle process immediately and run the taskqueue kernel thread, right? Would there ever be a situation where it doesn't do this? Adrian
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