Date: Thu, 20 Sep 2001 11:46:02 -0700 From: "mike varga" <mike.varga@cavium.com> To: <freebsd-arch@freebsd.org> Subject: Fw: kevent hangs Message-ID: <005b01c14204$8b49b350$4a10a8c0@stcla1.sfba.home.com>
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----- Original Message ----- From: "mike varga" <mike.varga@cavium.com> To: "Jonathan Lemon" <jlemon@flugsvamp.com> Sent: Thursday, September 20, 2001 11:28 AM Subject: Re: kevent hangs > I did some remote debuging > and found that the hanging was > coming from the repeated call of > kevent with 0 changes and 0 > events. > > I see the first call to add a change list > but there is some infinite loop > calling kevent with 0 changes and 0 > events. So my application never returns. > > It makes sense because the system > utilization went to 100% with > neerly half split across user and > system. > > > ----- Original Message ----- > From: "Jonathan Lemon" <jlemon@flugsvamp.com> > To: "mike varga" <mike.varga@cavium.com> > Sent: Wednesday, September 19, 2001 6:12 PM > Subject: Re: kevent hangs > > > > Hmm. If wchan is '-', then the process is not sleeping in the kernel. > > That's puzzling. The fact that you're able to kill the application > > indicates that a signal is delivered. Signals are only delivered when > > the process calls tsleep(), or is about to return to userland. > > > > Are you sure that the kevent() call never is returning? You could > > check this with ktrace. Otherwise, I don't know what is going on, > > I would suggest breaking out the kernel debugger and traceing the > > flow of execution. > > -- > > Jonathan > > > > > > On Wed, Sep 19, 2001 at 05:48:21PM -0700, mike varga wrote: > > > The WCHAN is "-". > > > > > > ----- Original Message ----- > > > From: "Jonathan Lemon" <jlemon@flugsvamp.com> > > > To: "mike varga" <mike.varga@cavium.com> > > > Sent: Wednesday, September 19, 2001 5:33 PM > > > Subject: Re: kevent hangs > > > > > > > > > > That looks right, and I don't see anything obviously wrong > > > > with the code. The same sequence works here (for a normal fd). > > > > > > > > If you do a 'ps -axl' on the machine, what WCHAN does it > > > > show the process in? > > > > -- > > > > Jonathan > > > > > > > > > > > > On Wed, Sep 19, 2001 at 05:01:10PM -0700, mike varga wrote: > > > > > > > > > > I see "cavium_kqfilter: 1 called", "cavium_kqfilter: 2 called", > > > > > "cavium_kqfilter: 3 called". > > > > > > > > > > I also see "kqfilter: 1 called". > > > > > > > > > > After I cancel the application, I > > > > > see "kqdetach: 1 called". > > > > > > > > > > > > > > > ----- Original Message ----- > > > > > From: "Jonathan Lemon" <jlemon@flugsvamp.com> > > > > > To: "mike varga" <mike.varga@cavium.com> > > > > > Sent: Wednesday, September 19, 2001 5:06 PM > > > > > Subject: Re: kevent hangs > > > > > > > > > > > > > > > > On Wed, Sep 19, 2001 at 04:42:31PM -0700, mike varga wrote: > > > > > > > I opted to break the changelist > > > > > > > and eventlist into 2 seperate calls. > > > > > > > > > > > > > > When I make the first call to add the > > > > > > > changelist, the call to kevent hangs. > > > > > > > > > > > > > > Does anyone know what is wrong? > > > > > > > > > > > > You don't say which (if any) of the kernel printfs are being hit, > > > > > > so it is hard to tell. > > > > > > -- > > > > > > Jonathan > > > > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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