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linux/arch/powerpc/kvm/timing.c

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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>
2008-12-02 21:51:57 +00:00
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
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>
2008-12-02 21:51:58 +00:00
* Copyright IBM Corp. 2008
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>
2008-12-02 21:51:57 +00:00
*
* Authors: Hollis Blanchard <hollisb@us.ibm.com>
* Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
*/
#include <linux/kvm_host.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <asm/time.h>
#include <asm-generic/div64.h>
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>
2008-12-02 21:51:58 +00:00
#include "timing.h"
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>
2008-12-02 21:51:57 +00:00
void kvmppc_init_timing_stats(struct kvm_vcpu *vcpu)
{
int i;
/* pause guest execution to avoid concurrent updates */
local_irq_disable();
mutex_lock(&vcpu->mutex);
vcpu->arch.last_exit_type = 0xDEAD;
for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
vcpu->arch.timing_count_type[i] = 0;
vcpu->arch.timing_max_duration[i] = 0;
vcpu->arch.timing_min_duration[i] = 0xFFFFFFFF;
vcpu->arch.timing_sum_duration[i] = 0;
vcpu->arch.timing_sum_quad_duration[i] = 0;
}
vcpu->arch.timing_last_exit = 0;
vcpu->arch.timing_exit.tv64 = 0;
vcpu->arch.timing_last_enter.tv64 = 0;
mutex_unlock(&vcpu->mutex);
local_irq_enable();
}
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>
2008-12-02 21:51:58 +00:00
static void add_exit_timing(struct kvm_vcpu *vcpu, u64 duration, int type)
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>
2008-12-02 21:51:57 +00:00
{
u64 old;
do_div(duration, tb_ticks_per_usec);
if (unlikely(duration > 0xFFFFFFFF)) {
printk(KERN_ERR"%s - duration too big -> overflow"
" duration %lld type %d exit #%d\n",
__func__, duration, type,
vcpu->arch.timing_count_type[type]);
return;
}
vcpu->arch.timing_count_type[type]++;
/* sum */
old = vcpu->arch.timing_sum_duration[type];
vcpu->arch.timing_sum_duration[type] += duration;
if (unlikely(old > vcpu->arch.timing_sum_duration[type])) {
printk(KERN_ERR"%s - wrap adding sum of durations"
" old %lld new %lld type %d exit # of type %d\n",
__func__, old, vcpu->arch.timing_sum_duration[type],
type, vcpu->arch.timing_count_type[type]);
}
/* square sum */
old = vcpu->arch.timing_sum_quad_duration[type];
vcpu->arch.timing_sum_quad_duration[type] += (duration*duration);
if (unlikely(old > vcpu->arch.timing_sum_quad_duration[type])) {
printk(KERN_ERR"%s - wrap adding sum of squared durations"
" old %lld new %lld type %d exit # of type %d\n",
__func__, old,
vcpu->arch.timing_sum_quad_duration[type],
type, vcpu->arch.timing_count_type[type]);
}
/* set min/max */
if (unlikely(duration < vcpu->arch.timing_min_duration[type]))
vcpu->arch.timing_min_duration[type] = duration;
if (unlikely(duration > vcpu->arch.timing_max_duration[type]))
vcpu->arch.timing_max_duration[type] = duration;
}
void kvmppc_update_timing_stats(struct kvm_vcpu *vcpu)
{
u64 exit = vcpu->arch.timing_last_exit;
u64 enter = vcpu->arch.timing_last_enter.tv64;
/* save exit time, used next exit when the reenter time is known */
vcpu->arch.timing_last_exit = vcpu->arch.timing_exit.tv64;
if (unlikely(vcpu->arch.last_exit_type == 0xDEAD || exit == 0))
return; /* skip incomplete cycle (e.g. after reset) */
/* update statistics for average and standard deviation */
add_exit_timing(vcpu, (enter - exit), vcpu->arch.last_exit_type);
/* enter -> timing_last_exit is time spent in guest - log this too */
add_exit_timing(vcpu, (vcpu->arch.timing_last_exit - enter),
TIMEINGUEST);
}
static const char *kvm_exit_names[__NUMBER_OF_KVM_EXIT_TYPES] = {
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>
2008-12-02 21:51:58 +00:00
[MMIO_EXITS] = "MMIO",
[DCR_EXITS] = "DCR",
[SIGNAL_EXITS] = "SIGNAL",
[ITLB_REAL_MISS_EXITS] = "ITLBREAL",
[ITLB_VIRT_MISS_EXITS] = "ITLBVIRT",
[DTLB_REAL_MISS_EXITS] = "DTLBREAL",
[DTLB_VIRT_MISS_EXITS] = "DTLBVIRT",
[SYSCALL_EXITS] = "SYSCALL",
[ISI_EXITS] = "ISI",
[DSI_EXITS] = "DSI",
[EMULATED_INST_EXITS] = "EMULINST",
[EMULATED_MTMSRWE_EXITS] = "EMUL_WAIT",
[EMULATED_WRTEE_EXITS] = "EMUL_WRTEE",
[EMULATED_MTSPR_EXITS] = "EMUL_MTSPR",
[EMULATED_MFSPR_EXITS] = "EMUL_MFSPR",
[EMULATED_MTMSR_EXITS] = "EMUL_MTMSR",
[EMULATED_MFMSR_EXITS] = "EMUL_MFMSR",
[EMULATED_TLBSX_EXITS] = "EMUL_TLBSX",
[EMULATED_TLBWE_EXITS] = "EMUL_TLBWE",
[EMULATED_RFI_EXITS] = "EMUL_RFI",
[DEC_EXITS] = "DEC",
[EXT_INTR_EXITS] = "EXTINT",
[HALT_WAKEUP] = "HALT",
[USR_PR_INST] = "USR_PR_INST",
[FP_UNAVAIL] = "FP_UNAVAIL",
[DEBUG_EXITS] = "DEBUG",
[TIMEINGUEST] = "TIMEINGUEST"
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>
2008-12-02 21:51:57 +00:00
};
static int kvmppc_exit_timing_show(struct seq_file *m, void *private)
{
struct kvm_vcpu *vcpu = m->private;
int i;
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>
2008-12-02 21:51:58 +00:00
seq_printf(m, "%s", "type count min max sum sum_squared\n");
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>
2008-12-02 21:51:57 +00:00
for (i = 0; i < __NUMBER_OF_KVM_EXIT_TYPES; i++) {
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>
2008-12-02 21:51:58 +00:00
seq_printf(m, "%12s %10d %10lld %10lld %20lld %20lld\n",
kvm_exit_names[i],
vcpu->arch.timing_count_type[i],
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>
2008-12-02 21:51:57 +00:00
vcpu->arch.timing_min_duration[i],
vcpu->arch.timing_max_duration[i],
vcpu->arch.timing_sum_duration[i],
vcpu->arch.timing_sum_quad_duration[i]);
}
return 0;
}
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>
2008-12-02 21:51:58 +00:00
/* Write 'c' to clear the timing statistics. */
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>
2008-12-02 21:51:57 +00:00
static ssize_t kvmppc_exit_timing_write(struct file *file,
const char __user *user_buf,
size_t count, loff_t *ppos)
{
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>
2008-12-02 21:51:58 +00:00
int err = -EINVAL;
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>
2008-12-02 21:51:57 +00:00
char c;
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>
2008-12-02 21:51:58 +00:00
if (count > 1) {
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>
2008-12-02 21:51:57 +00:00
goto done;
}
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>
2008-12-02 21:51:58 +00:00
if (get_user(c, user_buf)) {
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>
2008-12-02 21:51:57 +00:00
err = -EFAULT;
goto done;
}
if (c == 'c') {
struct seq_file *seqf = (struct seq_file *)file->private_data;
struct kvm_vcpu *vcpu = seqf->private;
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>
2008-12-02 21:51:58 +00:00
/* Write does not affect our buffers previously generated with
* show. seq_file is locked here to prevent races of init with
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>
2008-12-02 21:51:57 +00:00
* a show call */
mutex_lock(&seqf->lock);
kvmppc_init_timing_stats(vcpu);
mutex_unlock(&seqf->lock);
err = count;
}
done:
return err;
}
static int kvmppc_exit_timing_open(struct inode *inode, struct file *file)
{
return single_open(file, kvmppc_exit_timing_show, inode->i_private);
}
static struct file_operations kvmppc_exit_timing_fops = {
.owner = THIS_MODULE,
.open = kvmppc_exit_timing_open,
.read = seq_read,
.write = kvmppc_exit_timing_write,
.llseek = seq_lseek,
.release = single_release,
};
void kvmppc_create_vcpu_debugfs(struct kvm_vcpu *vcpu, unsigned int id)
{
static char dbg_fname[50];
struct dentry *debugfs_file;
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>
2008-12-02 21:51:58 +00:00
snprintf(dbg_fname, sizeof(dbg_fname), "vm%u_vcpu%u_timing",
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>
2008-12-02 21:51:57 +00:00
current->pid, id);
debugfs_file = debugfs_create_file(dbg_fname, 0666,
kvm_debugfs_dir, vcpu,
&kvmppc_exit_timing_fops);
if (!debugfs_file) {
printk(KERN_ERR"%s: error creating debugfs file %s\n",
__func__, dbg_fname);
return;
}
vcpu->arch.debugfs_exit_timing = debugfs_file;
}
void kvmppc_remove_vcpu_debugfs(struct kvm_vcpu *vcpu)
{
if (vcpu->arch.debugfs_exit_timing) {
debugfs_remove(vcpu->arch.debugfs_exit_timing);
vcpu->arch.debugfs_exit_timing = NULL;
}
}
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