Hi,
I see the same warning especially when resuming from a suspend (see
timestamps >=30-35sec) between Linux v3.5-rc1..v3.5-rc2.
$ sudo grep kvmclock.c /var/log/kern.log
Jun 4 21:11:32 fambox kernel: [ 784.037237] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Jun 5 20:35:57 fambox kernel: [ 1928.458060] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Jun 8 09:35:52 fambox kernel: [ 3290.134637] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Jun 8 09:35:52 fambox kernel: [ 3290.238592] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Jun 8 12:11:20 fambox kernel: [ 5777.023571] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
Jun 9 13:32:50 fambox kernel: [ 2778.842695] WARNING: at
arch/x86/kernel/kvmclock.c:127
kvm_check_and_clear_guest_paused+0x52/0x60()
>From [1]:
"...The warning itself is not required for the check_and_clear
function and can be removed as far as I am concerned."
>From [2] commit 3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494 ("kvmclock:
Add functions to check if the host has stopped the vm")
...
+bool kvm_check_and_clear_guest_paused(void)
+{
+ bool ret = false;
+ struct pvclock_vcpu_time_info *src;
+
+ /*
+ * per_cpu() is safe here because this function is only called from
+ * timer functions where preemption is already disabled.
+ */
+ WARN_ON(!in_atomic());
+ src = &__get_cpu_var(hv_clock);
+ if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) {
+ __this_cpu_and(hv_clock.flags, ~PVCLOCK_GUEST_STOPPED);
+ ret = true;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_check_and_clear_guest_paused);
+
...
( The export macro was dropped in a followup commit. )
So you mean "WARN_ON(!in_atomic());" can be deleted?
Regards,
- Sedat -
[1] http://www.spinics.net/lists/kvm/msg73732.html
[2] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blobdiff;f=arch/x86/kernel/kvmclock.c;h=4ba090ca689db5322fb242b98b53158de5447dc9;hp=f8492da65bfcb03e2775638ad5ce9502099d62c8;hb=3b5d56b9317fa7b5407dff1aa7b115bf6cdbd494;hpb=eae3ee7d8a7c59cf63441dedf28674889f5fc477
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
