freeze when strace X
in [Kernel]
|
From: Thomas Gleixner on 9 Jun 2010 16:50 On Wed, 9 Jun 2010, Matthew Garrett wrote: > On Wed, Jun 09, 2010 at 10:02:21PM +0200, Ortwin Gl�ck wrote: > > On 09.06.2010 21:52, Matthew Garrett wrote: > > > Just to make sure, you're not trying to strace X from within X, are you? > > > > Oh... now that you mention it... Is that a silly thing to do? > > strace X from a different terminal works fine :-) > > > > But freezing the system because of that? I mean an error message, log, anything > > would be "nice". > > strace needs to output text via X, which generates output which needs to > be output via X... and you'll tend to deadlock. If X is holding any > interesting kernel locks at that point then it wouldn't surprise me if > the machine ends up dead. Nothing to do with kernel locks. strace hooks into the syscall and intercepts the data, so X is stopped at that point. Now try to send output to a program which you stopped yourself :) Thanks, tglx
From: Matthew Garrett on 9 Jun 2010 17:00 On Wed, Jun 09, 2010 at 10:47:23PM +0200, Thomas Gleixner wrote: > On Wed, 9 Jun 2010, Matthew Garrett wrote: > > strace needs to output text via X, which generates output which needs to > > be output via X... and you'll tend to deadlock. If X is holding any > > interesting kernel locks at that point then it wouldn't surprise me if > > the machine ends up dead. > > Nothing to do with kernel locks. strace hooks into the syscall and > intercepts the data, so X is stopped at that point. Now try to send > output to a program which you stopped yourself :) Oh, yeah, and ctrl+alt+fwhatever is handled by X. -- Matthew Garrett | mjg59(a)srcf.ucam.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
First
|
Prev
|
Pages: 1 2 Prev: Why is kslowd accumulating so much CPU time? Next: floppy: cleanup patches |