[libvirt] [PATCH] qemu: Use atomic ops for driver->nactive
--- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_process.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index b5a3281..a6bd527 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -168,7 +168,7 @@ struct _virQEMUDriver { virCgroupPtr cgroup; /* Atomic inc/dec only */ - size_t nactive; + unsigned int nactive; /* Immutable pointers. Caller must provide locking */ virStateInhibitCallback inhibitCallback; diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 74406a6..b612d72 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -69,6 +69,7 @@ #include "virtime.h" #include "virnetdevtap.h" #include "virbitmap.h" +#include "viratomic.h" #define VIR_FROM_THIS VIR_FROM_QEMU @@ -3300,9 +3301,8 @@ qemuProcessReconnect(void *opaque) goto error; } - if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++; endjob: if (!qemuDomainObjEndJob(driver, obj)) @@ -3589,9 +3589,8 @@ int qemuProcessStart(virConnectPtr conn, qemuDomainSetFakeReboot(driver, vm, false); virDomainObjSetState(vm, VIR_DOMAIN_SHUTOFF, VIR_DOMAIN_SHUTOFF_UNKNOWN); - if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++; /* Run an early hook to set-up missing devices */ if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) { @@ -4188,8 +4187,7 @@ void qemuProcessStop(virQEMUDriverPtr driver, */ vm->def->id = -1; - driver->nactive--; - if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntDecAndTest(&driver->nactive) && driver->inhibitCallback) driver->inhibitCallback(false, driver->inhibitOpaque); if ((logfile = qemuDomainCreateLog(driver, vm, true)) < 0) { @@ -4443,9 +4441,8 @@ int qemuProcessAttach(virConnectPtr conn ATTRIBUTE_UNUSED, vm->def->id = qemuDriverAllocateID(driver); - if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++; if (virFileMakePath(cfg->logDir) < 0) { virReportSystemError(errno, -- 1.8.1.2
On 19.02.2013 14:58, Jiri Denemark wrote:
--- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_process.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index b5a3281..a6bd527 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -168,7 +168,7 @@ struct _virQEMUDriver { virCgroupPtr cgroup;
/* Atomic inc/dec only */ - size_t nactive; + unsigned int nactive;
Hopefully nobody gets an overflow here. ACK Michal
On Tue, Feb 19, 2013 at 03:13:44PM +0100, Michal Privoznik wrote:
On 19.02.2013 14:58, Jiri Denemark wrote:
--- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_process.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index b5a3281..a6bd527 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -168,7 +168,7 @@ struct _virQEMUDriver { virCgroupPtr cgroup;
/* Atomic inc/dec only */ - size_t nactive; + unsigned int nactive;
Hopefully nobody gets an overflow here.
The limit on number of guests in the RPC protocol is way lower than 2^32, so you can't get there. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Tue, Feb 19, 2013 at 02:58:30PM +0100, Jiri Denemark wrote:
--- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_process.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index b5a3281..a6bd527 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -168,7 +168,7 @@ struct _virQEMUDriver { virCgroupPtr cgroup;
/* Atomic inc/dec only */ - size_t nactive; + unsigned int nactive;
/* Immutable pointers. Caller must provide locking */ virStateInhibitCallback inhibitCallback; diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 74406a6..b612d72 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -69,6 +69,7 @@ #include "virtime.h" #include "virnetdevtap.h" #include "virbitmap.h" +#include "viratomic.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -3300,9 +3301,8 @@ qemuProcessReconnect(void *opaque) goto error; }
- if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++;
endjob: if (!qemuDomainObjEndJob(driver, obj)) @@ -3589,9 +3589,8 @@ int qemuProcessStart(virConnectPtr conn, qemuDomainSetFakeReboot(driver, vm, false); virDomainObjSetState(vm, VIR_DOMAIN_SHUTOFF, VIR_DOMAIN_SHUTOFF_UNKNOWN);
- if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++;
/* Run an early hook to set-up missing devices */ if (virHookPresent(VIR_HOOK_DRIVER_QEMU)) { @@ -4188,8 +4187,7 @@ void qemuProcessStop(virQEMUDriverPtr driver, */ vm->def->id = -1;
- driver->nactive--; - if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntDecAndTest(&driver->nactive) && driver->inhibitCallback) driver->inhibitCallback(false, driver->inhibitOpaque);
if ((logfile = qemuDomainCreateLog(driver, vm, true)) < 0) { @@ -4443,9 +4441,8 @@ int qemuProcessAttach(virConnectPtr conn ATTRIBUTE_UNUSED,
vm->def->id = qemuDriverAllocateID(driver);
- if (!driver->nactive && driver->inhibitCallback) + if (virAtomicIntInc(&driver->nactive) == 1 && driver->inhibitCallback) driver->inhibitCallback(true, driver->inhibitOpaque); - driver->nactive++;
if (virFileMakePath(cfg->logDir) < 0) { virReportSystemError(errno,
ACK This is something I had done already but lost in a rebase merge :-( Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|
On Tue, Feb 19, 2013 at 14:20:14 +0000, Daniel P. Berrange wrote:
On Tue, Feb 19, 2013 at 02:58:30PM +0100, Jiri Denemark wrote:
--- src/qemu/qemu_conf.h | 2 +- src/qemu/qemu_process.c | 13 +++++-------- 2 files changed, 6 insertions(+), 9 deletions(-)
ACK
This is something I had done already but lost in a rebase merge :-(
Thanks, pushed. Jirka
participants (3)
-
Daniel P. Berrange -
Jiri Denemark -
Michal Privoznik