On Tue, Jun 14, 2011 at 10:15:36AM +0100, Daniel P. Berrange wrote:
On Tue, Jun 07, 2011 at 10:02:55AM +0900, Minoru Usui wrote:
virNodeGetCPUStats: Implement linux support
Signed-off-by: Minoru Usui <usui@mxm.nes.nec.co.jp> --- src/libvirt_private.syms | 1 + src/lxc/lxc_driver.c | 1 + src/nodeinfo.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++ src/nodeinfo.h | 6 ++- src/qemu/qemu_driver.c | 1 + src/uml/uml_driver.c | 1 + 6 files changed, 147 insertions(+), 1 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index e6ab870..a8c77f2 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -731,6 +731,7 @@ virNodeDeviceObjUnlock;
# nodeinfo.h nodeCapsInitNUMA; +nodeGetCPUStats; nodeGetCellsFreeMemory; nodeGetFreeMemory; nodeGetInfo; diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index 8eb87a2..3286154 100644 --- a/src/lxc/lxc_driver.c +++ b/src/lxc/lxc_driver.c @@ -2779,6 +2779,7 @@ static virDriver lxcDriver = { .domainSetSchedulerParameters = lxcSetSchedulerParameters, /* 0.5.0 */ .domainSetSchedulerParametersFlags = lxcSetSchedulerParametersFlags, /* 0.9.2 */ .domainInterfaceStats = lxcDomainInterfaceStats, /* 0.7.3 */ + .nodeGetCPUStats = nodeGetCPUStats, /* 0.9.3 */ .nodeGetCellsFreeMemory = nodeGetCellsFreeMemory, /* 0.6.5 */ .nodeGetFreeMemory = nodeGetFreeMemory, /* 0.6.5 */ .domainEventRegister = lxcDomainEventRegister, /* 0.7.0 */ diff --git a/src/nodeinfo.c b/src/nodeinfo.c index f55c83e..39afd0e 100644 --- a/src/nodeinfo.c +++ b/src/nodeinfo.c @@ -57,12 +57,20 @@ #ifdef __linux__ # define CPUINFO_PATH "/proc/cpuinfo" # define CPU_SYS_PATH "/sys/devices/system/cpu" +# define PROCSTAT_PATH "/proc/stat" + +# define LINUX_NB_CPU_STATS 4
/* NB, this is not static as we need to call it from the testsuite */ int linuxNodeInfoCPUPopulate(FILE *cpuinfo, virNodeInfoPtr nodeinfo, bool need_hyperthreads);
+int linuxNodeGetCPUStats(FILE *procstat, + int cpuNum, + virCPUStatsPtr params, + int *nparams); + /* Return the positive decimal contents of the given * CPU_SYS_PATH/cpu%u/FILE, or -1 on error. If MISSING_OK and the * file could not be found, return 1 instead of an error; this is @@ -378,6 +386,108 @@ int linuxNodeInfoCPUPopulate(FILE *cpuinfo, return 0; }
+#define TICK_TO_NSEC (1000ull * 1000ull * 1000ull / sysconf(_SC_CLK_TCK)) +#define CPU_HEADER_LEN 8 + +int linuxNodeGetCPUStats(FILE *procstat, + int cpuNum, + virCPUStatsPtr params, + int *nparams) +{ + int ret = -1; + char line[1024]; + unsigned long long usr, ni, sys, idle, iowait; + unsigned long long irq, softirq, steal, guest, guest_nice; + char cpu_header[CPU_HEADER_LEN]; + + if ((*nparams) == 0) { + /* Current number of cpu stats supported by linux */ + *nparams = LINUX_NB_CPU_STATS; + ret = 0; + goto cleanup; + } + + if ((*nparams) != LINUX_NB_CPU_STATS) { + nodeReportError(VIR_ERR_INVALID_ARG, + "%s", _("Invalid parameter count")); + goto cleanup; + } + + if (cpuNum == VIR_CPU_STATS_ALL_CPUS) { + strcpy(cpu_header, "cpu"); + } else { + sprintf(cpu_header, "cpu%d", cpuNum); + }
cpu_header is declared to be 8 bytes in size, which only allows for integers upto 4 digits long, before we get a buffer overflow here.
gnulib has some macro which can be used to declare a string buffer large enough to hold an integer, but I can't remember what the macro is called right now. Hopefully Eric will remind us shortly....
Jim Meyering reminded me that it is INT_BUFSIZE_BOUND. So eg you want todo char cpu_header[3 + INT_BUFSIZE_BOUND(cpuNum) + 1]; to allow enough space for 'cpu' + any cpuNum value formatted as a string + the trailing NULL. Regards, 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 :|