Commit Graph

9 Commits

Author SHA1 Message Date
Stuart Yoder 24294b9a3f KVM: PPC: fix partial application of "exit timing in ticks"
When http://www.spinics.net/lists/kvm-ppc/msg02664.html
was applied to produce commit b51e7aa7ed6d8d134d02df78300ab0f91cfff4d2,
the removal of the conversion in add_exit_timing was left out.

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-12 13:16:28 +03:00
Stuart Yoder 1a040b26c5 KVM: PPC: use ticks, not usecs, for exit timing
Convert to microseconds when displaying
(with fix from Bharat Bhushan <Bharat.Bhushan@freescale.com>).

This reduces rounding error with large quantities of short exits.

Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-05-22 08:47:49 -04:00
Bharat Bhushan 09000adb86 KVM: PPC: Fix issue clearing exit timing counters
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.Bhushan@freescale.com>
Acked-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-05-11 07:57:04 -04:00
Scott Wood bb59e9748f KVM: PPC: BookE: fix sleep with interrupts disabled
It is not legal to call mutex_lock() with interrupts disabled.
This will assert with debug checks enabled.

If there's a real need to disable interrupts here, it could be done
after the mutex is acquired -- but I don't see why it's needed at all.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Reviewed-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2010-11-05 14:42:28 -02:00
Joe Perches ea01c6b487 powerpc: Remove unnecessary casts of private_data
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-07-31 14:56:31 +10:00
Benjamin Herrenschmidt e0ea8b2c06 powerpc/kvm: Fix non-modular build
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-11-05 17:17:12 +11:00
Alexey Dobriyan 828c09509b const: constify remaining file_operations
[akpm@linux-foundation.org: fix KVM]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01 16:11:11 -07:00
Hollis Blanchard 7b7015914b KVM: ppc: mostly cosmetic updates to the exit timing accounting code
The only significant changes were to kvmppc_exit_timing_write() and
kvmppc_exit_timing_show(), both of which were dramatically simplified.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:41 +02:00
Hollis Blanchard 73e75b416f KVM: ppc: Implement in-kernel exit timing statistics
Existing KVM statistics are either just counters (kvm_stat) reported for
KVM generally or trace based aproaches like kvm_trace.
For KVM on powerpc we had the need to track the timings of the different exit
types. While this could be achieved parsing data created with a kvm_trace
extension this adds too much overhead (at least on embedded PowerPC) slowing
down the workloads we wanted to measure.

Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
code. These statistic is available per vm&vcpu under the kvm debugfs directory.
As this statistic is low, but still some overhead it can be enabled via a
.config entry and should be off by default.

Since this patch touched all powerpc kvm_stat code anyway this code is now
merged and simplified together with the exit timing statistic code (still
working with exit timing disabled in .config).

Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2008-12-31 16:55:41 +02:00