[libvirt] [v5 9/9] Resctrl: concurrence support
Eli Qiao
liyong.qiao at intel.com
Mon Feb 13 07:46:47 UTC 2017
The internal struct list domainall is a list which are resctral domain
status shared by all VMs, especiall the default domain, each VM should
access it concomitantly. Ues a mutex to control it.
Each bank's cache_left field is also a global shared resource we need
to be care, add a mutex for each bank.
We need also to add lock to access /sys/fs/resctrl, use flock.
Signed-off-by: Eli Qiao <liyong.qiao at intel.com>
---
src/util/virresctrl.c | 89 ++++++++++++++++++++++++++++++++++++++++++++-------
src/util/virresctrl.h | 3 ++
2 files changed, 81 insertions(+), 11 deletions(-)
diff --git a/src/util/virresctrl.c b/src/util/virresctrl.c
index 3552761..26df276 100644
--- a/src/util/virresctrl.c
+++ b/src/util/virresctrl.c
@@ -24,6 +24,7 @@
#if defined HAVE_SYS_SYSCALL_H
# include <sys/syscall.h>
#endif
+#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
@@ -68,8 +69,8 @@ do { \
#define VIR_RESCTRL_GET_SCHEMATA(count) ((1 << count) - 1)
-#define VIR_RESCTRL_SET_SCHEMATA(p, type, pos, val) \
- p->schematas[type]->schemata_items[pos] = val
+#define VIR_RESCTRL_LOCK(fd, op) flock(fd, op)
+#define VIR_RESCTRL_UNLOCK(fd) flock(fd, LOCK_UN)
/**
* a virResSchemata represents a schemata object under a resource control
@@ -114,6 +115,8 @@ typedef virResCtrlDomain *virResCtrlDomainPtr;
struct _virResCtrlDomain {
unsigned int num_domains;
virResDomainPtr domains;
+
+ virMutex lock;
};
@@ -166,16 +169,34 @@ static int virResCtrlGetStr(const char *domain_name, const char *item_name, char
{
char *path;
int rc = 0;
+ int readfd;
+ int len;
CONSTRUCT_RESCTRL_PATH(domain_name, item_name);
- if (virFileReadAll(path, MAX_FILE_LEN, ret) < 0) {
- rc = -1;
+ if (!virFileExists(path))
+ goto cleanup;
+
+ if ((readfd = open(path, O_RDONLY)) < 0)
+ goto cleanup;
+
+ if (VIR_RESCTRL_LOCK(readfd, LOCK_SH) < 0) {
+ virReportSystemError(errno, _("Unable to lock '%s'"), path);
+ goto cleanup;
+ }
+
+ len = virFileReadLimFD(readfd, MAX_FILE_LEN, ret);
+
+ if (len < 0) {
+ virReportSystemError(errno, _("Failed to read file '%s'"), path);
goto cleanup;
}
+ rc = 0;
cleanup:
VIR_FREE(path);
+ VIR_RESCTRL_UNLOCK(readfd);
+ VIR_FORCE_CLOSE(readfd);
return rc;
}
@@ -616,6 +637,9 @@ virResCtrlRefresh(void)
unsigned int origin_count = domainall.num_domains;
virResDomainPtr p, pre, del;
pre = domainall.domains;
+
+ virMutexLock(&domainall.lock);
+
p = del = NULL;
if (pre)
p = pre->next;
@@ -640,10 +664,11 @@ virResCtrlRefresh(void)
p = p->next;
}
VIR_FREE(tasks);
-
}
- return virResCtrlRefreshSchemata();
+ virResCtrlRefreshSchemata();
+ virMutexUnlock(&domainall.lock);
+ return 0;
}
/* Get a domain ptr by domain's name*/
@@ -689,6 +714,11 @@ virResCtrlWrite(const char *name, const char *item, const char *content)
if ((writefd = open(path, O_WRONLY | O_APPEND, S_IRUSR | S_IWUSR)) < 0)
goto cleanup;
+ if (VIR_RESCTRL_LOCK(writefd, LOCK_EX) < 0) {
+ virReportSystemError(errno, _("Unable to lock '%s'"), path);
+ goto cleanup;
+ }
+
if (safewrite(writefd, content, strlen(content)) < 0)
goto cleanup;
@@ -696,6 +726,7 @@ virResCtrlWrite(const char *name, const char *item, const char *content)
cleanup:
VIR_FREE(path);
+ VIR_RESCTRL_UNLOCK(writefd);
VIR_FORCE_CLOSE(writefd);
return rc;
}
@@ -868,10 +899,15 @@ static int
virResCtrlAppendDomain(virResDomainPtr dom)
{
virResDomainPtr p = domainall.domains;
+
+ virMutexLock(&domainall.lock);
+
while (p->next != NULL) p = p->next;
p->next = dom;
dom->pre = p;
domainall.num_domains += 1;
+
+ virMutexUnlock(&domainall.lock);
return 0;
}
@@ -894,18 +930,22 @@ virResCtrlCalculateSchemata(int type,
{
size_t i;
int count;
+ int rc = -1;
virResDomainPtr p;
unsigned int tmp_schemata;
unsigned int schemata_sum = 0;
int pair_type = 0;
+ virMutexLock(&resctrlall[type].cache_banks[sid].lock);
+
if (resctrlall[type].cache_banks[sid].cache_left < size) {
VIR_ERROR(_("Not enough cache left on bank %u"), hostid);
- return -1;
+ goto cleanup;
}
+
if ((count = size / resctrlall[type].cache_banks[sid].cache_min) <= 0) {
VIR_ERROR(_("Error cache size %llu"), size);
- return -1;
+ goto cleanup;
}
tmp_schemata = VIR_RESCTRL_GET_SCHEMATA(count);
@@ -920,7 +960,7 @@ virResCtrlCalculateSchemata(int type,
if (type == VIR_RDT_RESOURCE_L3CODE)
pair_type = VIR_RDT_RESOURCE_L3DATA;
- for (i = 1; i < domainall.num_domains; i ++) {
+ for (i = 1; i < domainall.num_domains; i++) {
schemata_sum |= p->schematas[type]->schemata_items[sid].schemata;
if (pair_type > 0)
schemata_sum |= p->schematas[pair_type]->schemata_items[sid].schemata;
@@ -931,7 +971,16 @@ virResCtrlCalculateSchemata(int type,
while ((tmp_schemata & schemata_sum) != 0)
tmp_schemata = tmp_schemata >> 1;
- return tmp_schemata;
+
+ resctrlall[type].cache_banks[sid].cache_left -= size;
+ if (pair_type > 0)
+ resctrlall[pair_type].cache_banks[sid].cache_left = resctrlall[type].cache_banks[sid].cache_left;
+
+ rc = tmp_schemata;
+
+ cleanup:
+ virMutexUnlock(&resctrlall[type].cache_banks[sid].lock);
+ return rc;
}
int virResCtrlSetCacheBanks(virDomainCachetunePtr cachetune,
@@ -1043,7 +1092,7 @@ int virResCtrlUpdate(void)
int
virResCtrlInit(void)
{
- size_t i = 0;
+ size_t i, j;
char *tmp;
int rc = 0;
@@ -1063,6 +1112,24 @@ virResCtrlInit(void)
domainall.domains = virResCtrlGetAllDomains(&(domainall.num_domains));
+ for (i = 0; i < VIR_RDT_RESOURCE_LAST; i++) {
+ if (VIR_RESCTRL_ENABLED(i)) {
+ for (j = 0; j < resctrlall[i].num_banks; j++) {
+ if (virMutexInit(&resctrlall[i].cache_banks[j].lock) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Unable to initialize mutex"));
+ return -1;
+ }
+ }
+ }
+ }
+
+ if (virMutexInit(&domainall.lock) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+ _("Unable to initialize mutex"));
+ return -1;
+ }
+
if ((rc = virResCtrlRefresh()) < 0)
VIR_ERROR(_("Failed to refresh resource control"));
return rc;
diff --git a/src/util/virresctrl.h b/src/util/virresctrl.h
index ee7e115..07b298d 100644
--- a/src/util/virresctrl.h
+++ b/src/util/virresctrl.h
@@ -27,6 +27,7 @@
# include "virutil.h"
# include "virbitmap.h"
# include "domain_conf.h"
+# include "virthread.h"
#define MAX_CPU_SOCKET_NUM 8
@@ -49,6 +50,8 @@ struct _virResCacheBank {
unsigned long long cache_left;
unsigned long long cache_min;
virBitmapPtr cpu_mask;
+
+ virMutex lock;
};
/**
--
1.9.1
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