> -----Original Message----- > From: Alexander Graf [mailto:ag...@suse.de] > Sent: Tuesday, March 15, 2011 8:11 PM > To: Bhushan Bharat-R65777 > Cc: kvm-ppc@vger.kernel.org; bharatb.ya...@gmail.com; Bhushan Bharat- > R65777 > Subject: Re: [PATCH] Issue in exit timing clearance > > > On 15.03.2011, at 06:29, Bharat Bhushan wrote: > > > Following dump is observed on host when clearing the exit timing > > counters > > > > [root@p1021mds kvm]# echo -n 'c' > vm1200_vcpu0_timing > > INFO: task echo:1276 blocked for more than 120 seconds. > > "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this > message. > > echo D 0ff5bf94 0 1276 1190 0x00000000 > > Call Trace: > > [c2157e40] [c0007908] __switch_to+0x9c/0xc4 [c2157e50] [c040293c] > > schedule+0x1b4/0x3bc [c2157e90] [c04032dc] > > __mutex_lock_slowpath+0x74/0xc0 [c2157ec0] [c00369e4] > > kvmppc_init_timing_stats+0x20/0xb8 > > [c2157ed0] [c0036b00] kvmppc_exit_timing_write+0x84/0x98 > > [c2157ef0] [c00b9f90] vfs_write+0xc0/0x16c [c2157f10] [c00ba284] > > sys_write+0x4c/0x90 [c2157f40] [c000e320] ret_from_syscall+0x0/0x3c > > > > The vcpu->mutex is used by kvm_ioctl_* (KVM_RUN etc) and same > > was used when clearing the stats (in kvmppc_init_timing_stats()). What > > happens is that when the guest is idle then it held the vcpu->mutx. > > While the exiting timing process waits for guest to release the > > vcpu->mutex and a hang state is reached. > > > > Now using seprate lock for exit timing stats. > > > > Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com> > > Looks good from a 10000 feet perspective. My BookE box is currently down, > so I can't test it, but I assume you have verified it works just fine? > If so, please CC k...@vger.kernel.org, so Avi can take it in the tree with > my signed-off (after I tested it ;)). >
Hi Alex, I have tested this and works fine for me. Please let me know when you complete your testing so that I send to k...@vger.kernel.org. Thanks -Bharat -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
