On Mon, Aug 28, 2006 at 08:38:22PM -0700, Piet Delaney wrote: > On Fri, 2006-08-25 at 19:54 -0700, Piet Delaney wrote: > > I just noticed kgdb for 2.6.12 not stopping CPU's. This could be > > aggravated by the fact that I disabled optimization for the complete > > kernel. I've been getting NMI problems for a while and I suspect that > > compiling -O0 just aggravated the problem: > > Looks like I found the land mine. It seems kgdb_handle_exception() has > a count for the number of times the trapped CPU should loop waiting for > the other CPU's to stop. Apparently this constant is too small for our > system, resulting in the gdb message about CPU not being stopped. > > // #define ROUNDUP_WAIT 64000 > // #define ROUNDUP_WAIT 640000 > #define ROUNDUP_WAIT 64000000 > > I'm currently using a value 1k larger so that printk's in the > other threads can complete. 64000 appears to be a marginal > value and compiling the kernel -O0 seems to push us over the > edge. I see little downsize on making it larger. Looks like > the 2.6.16 patch has 640000; so it's only a bug for the older > patches like we use in 2.6.12.
And here-in lies the danger in using older snapshots. The constant was bumped because it was too small on some large'ish x86_64 system I was using and ran into the problem of not getting all CPUs in sync. I hope that when Amit is done with the SMP rework this problem will simply go away.. :) -- Tom Rini ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
