Hi Laurent,
A note and patch from Samuel alerted me to your commits
9ac52315d4cf5f561f36dabaf0720c00d3553162 and
5e84cfde51cf303d368fcb48f22059f37b3872de, which in 2.6.24 changed /proc/stat
and /proc/PID/stat. Would you please CC me on kernel-userspace interface
changes, so that they have a chance of getting documented in man-pages.
(I see that Andrew P tried to get something added to
Documentation/filesystems/proc.txt, but that doesn't seem to have made it in.)
Below is a patch against the proc.5 man page by Samuel and I to document these
changes. Do the changes look okay to you? The first part is the change for
/proc/<pid>/stat, and the other is for /proc/stat.
Cheers,
Michael
===================================================================
--- proc.5 (revision 4046)
+++ proc.5 (working copy)
@@ -753,6 +753,13 @@
.TP
\fIdelayacct_blkio_ticks\fP %llu (since Linux 2.6.18)
Aggregated block I/O delays, measured in clock ticks (centiseconds).
+.TP
+\fIguest_time\fP %lu (since Linux 2.6.24)
+Guest time of the process (time spent running a virtual CPU
+for a guest operating system), in centiseconds.
+.TP
+\fIcguest_time\fP %ld (since Linux 2.6.24)
+Guest time of the process's children, in centiseconds.
.RE
.TP
.I /proc/[number]/statm
@@ -1510,6 +1517,12 @@
.I steal
\- stolen time, which is the time spent in other operating systems when
running in a virtualized environment
+
+Since Linux 2.6.24, there is a ninth column,
+.IR guest ,
+which is the time spent running a virtual CPU for guest
+operating systems under teh control of the Linux kernel.
+.\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de
.TP
\fIpage 5741 1808\fP
The number of pages the system paged in and the number that were paged
Am Sonntag, 22. Juni 2008 schrieb Michael Kerrisk:
> Hi Laurent,
>
> A note and patch from Samuel alerted me to your commits
> 9ac52315d4cf5f561f36dabaf0720c00d3553162 and
> 5e84cfde51cf303d368fcb48f22059f37b3872de, which in 2.6.24 changed /proc/stat
> and /proc/PID/stat. Would you please CC me on kernel-userspace interface
> changes, so that they have a chance of getting documented in man-pages.
[...]
> +.TP
> +\fIguest_time\fP %lu (since Linux 2.6.24)
> +Guest time of the process (time spent running a virtual CPU
> +for a guest operating system), in centiseconds.
> +.TP
> +\fIcguest_time\fP %ld (since Linux 2.6.24)
> +Guest time of the process's children, in centiseconds.
[...]
> +
> +Since Linux 2.6.24, there is a ninth column,
> +.IR guest ,
> +which is the time spent running a virtual CPU for guest
> +operating systems under teh control of the Linux kernel.
> +.\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de
Maybe you should mention that guest time is accounted twice: user and guest.
So if guest time aware userspace wants to to calcuate user time without
guests time, it should subtract the guest time from user.
Christian
Le dimanche 22 juin 2008 à 09:31 +0200, Michael Kerrisk a écrit :
> Hi Laurent,
Hi Michael,
> A note and patch from Samuel alerted me to your commits
> 9ac52315d4cf5f561f36dabaf0720c00d3553162 and
> 5e84cfde51cf303d368fcb48f22059f37b3872de, which in 2.6.24 changed /proc/stat
> and /proc/PID/stat. Would you please CC me on kernel-userspace interface
> changes, so that they have a chance of getting documented in man-pages.
>
> (I see that Andrew P tried to get something added to
> Documentation/filesystems/proc.txt, but that doesn't seem to have made it in.)
>
> Below is a patch against the proc.5 man page by Samuel and I to document these
> changes. Do the changes look okay to you? The first part is the change for
> /proc/<pid>/stat, and the other is for /proc/stat.
Thank you for that. It seems correct to me (except a typo).
You must also notes that "user time" includes "guest time", if you want
real "user time" you must subtract "guest time".
The "guest time" is included in "user time" to not loose it when the
"reader" is not aware of the "guest time".
> Cheers,
>
> Michael
Thank you,
Laurent
>
>
> ===================================================================
> --- proc.5 (revision 4046)
> +++ proc.5 (working copy)
> @@ -753,6 +753,13 @@
> .TP
> \fIdelayacct_blkio_ticks\fP %llu (since Linux 2.6.18)
> Aggregated block I/O delays, measured in clock ticks (centiseconds).
> +.TP
> +\fIguest_time\fP %lu (since Linux 2.6.24)
> +Guest time of the process (time spent running a virtual CPU
> +for a guest operating system), in centiseconds.
> +.TP
> +\fIcguest_time\fP %ld (since Linux 2.6.24)
> +Guest time of the process's children, in centiseconds.
> .RE
> .TP
> .I /proc/[number]/statm
> @@ -1510,6 +1517,12 @@
> .I steal
> \- stolen time, which is the time spent in other operating systems when
> running in a virtualized environment
> +
> +Since Linux 2.6.24, there is a ninth column,
> +.IR guest ,
> +which is the time spent running a virtual CPU for guest
> +operating systems under teh control of the Linux kernel.
typo: "teh" -> "the"
> +.\" See Changelog entry for 5e84cfde51cf303d368fcb48f22059f37b3872de
> .TP
> \fIpage 5741 1808\fP
> The number of pages the system paged in and the number that were paged
>
>
>
>
--
------------- [email protected] ---------------
"The best way to predict the future is to invent it."
- Alan Kay
On Mon, Jun 23, 2008 at 10:48 AM, Laurent Vivier
<[email protected]> wrote:
> Le dimanche 22 juin 2008 ? 09:31 +0200, Michael Kerrisk a ?crit :
>> Hi Laurent,
>
> Hi Michael,
>
>> A note and patch from Samuel alerted me to your commits
>> 9ac52315d4cf5f561f36dabaf0720c00d3553162 and
>> 5e84cfde51cf303d368fcb48f22059f37b3872de, which in 2.6.24 changed /proc/stat
>> and /proc/PID/stat. Would you please CC me on kernel-userspace interface
>> changes, so that they have a chance of getting documented in man-pages.
>>
>> (I see that Andrew P tried to get something added to
>> Documentation/filesystems/proc.txt, but that doesn't seem to have made it in.)
>>
>> Below is a patch against the proc.5 man page by Samuel and I to document these
>> changes. Do the changes look okay to you? The first part is the change for
>> /proc/<pid>/stat, and the other is for /proc/stat.
>
> Thank you for that. It seems correct to me (except a typo).
>
> You must also notes that "user time" includes "guest time", if you want
> real "user time" you must subtract "guest time".
> The "guest time" is included in "user time" to not loose it when the
> "reader" is not aware of the "guest time".
Hi Laurent (and Christian)
So, I just want to confirm. You are saying that guest_time and
cguest_time are respectively also included in the following fields
utime %lu
The number of jiffies that this process has been
scheduled in user mode.
[...]
cutime %ld
The number of jiffies that this process's waited-
for children have been scheduled in user mode.
(See also times(2).)
Right?
(In fs/proc/array.c, those are the two lines from
cputime_to_clock_t(utime),
cputime_to_clock_t(cutime),
)
Cheers,
Michael
On Mon, Jun 23, 2008 at 12:51:11PM +0200, Michael Kerrisk wrote:
> > You must also notes that "user time" includes "guest time", if you want
> > real "user time" you must subtract "guest time".
> > The "guest time" is included in "user time" to not loose it when the
> > "reader" is not aware of the "guest time".
>
> Hi Laurent (and Christian)
>
> So, I just want to confirm. You are saying that guest_time and
> cguest_time are respectively also included in the following fields
>
> utime %lu
...
> cutime %ld
...
> Right?
If this function in ./kernel/sched.c is anything to go by and I'm not
being a complete noob, yes:
/*
* Account guest cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in virtual machine since the last update
*/
static void account_guest_time(struct task_struct *p, cputime_t cputime)
{
cputime64_t tmp;
struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat;
tmp = cputime_to_cputime64(cputime);
p->utime = cputime_add(p->utime, cputime);
p->gtime = cputime_add(p->gtime, cputime);
cpustat->user = cputime64_add(cpustat->user, tmp);
cpustat->guest = cputime64_add(cpustat->guest, tmp);
}
As such, I'll follow up with a new version of my previous patch.
AP
Git patch 5e84cfde51cf303d368fcb48f22059f37b3872de introduced a new
field to /proc/stat that represents guest (virtual cpu) time.
Git patch 9ac52315d4cf5f561f36dabaf0720c00d3553162 introduced the same
to /proc/<pid>/stat along with a guest time of the tasks children.
The patch below adds descriptions of these fields to the procfs
documentation included in the kernel.
Signed-Off-By: Andrew P <[email protected]>
diff -aur linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt
--- linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt 2008-06-23 22:27:13.000000000 +1000
+++ linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt 2008-06-24 22:16:53.000000000 +1000
@@ -210,9 +210,9 @@
cmin_flt number of minor faults with child's
maj_flt number of major faults
cmaj_flt number of major faults with child's
- utime user mode jiffies
+ utime user mode jiffies (including gtime below*)
stime kernel mode jiffies
- cutime user mode jiffies with child's
+ cutime user mode jiffies with child's (including cgtime below*)
cstime kernel mode jiffies with child's
priority priority level
nice nice level
@@ -239,6 +239,11 @@
rt_priority realtime priority
policy scheduling policy (man sched_setscheduler)
blkio_ticks time spent waiting for block IO
+ gtime guest (virtual CPU) CPU time in jiffies
+ cgtime guests' children's CPU time in jiffies
+
+* gtime and cgtime are included in these values so that applications that are
+ not aware of these fields do not lose time in their calculations.
..............................................................................
@@ -828,9 +833,9 @@
since the system first booted. For a quick look, simply cat the file:
> cat /proc/stat
- cpu 2255 34 2290 22625563 6290 127 456 0
- cpu0 1132 34 1441 11311718 3675 127 438 0
- cpu1 1123 0 849 11313845 2614 0 18 0
+ cpu 2255 34 2290 22625563 6290 127 456 0 0
+ cpu0 1132 34 1441 11311718 3675 127 438 0 0
+ cpu1 1123 0 849 11313845 2614 0 18 0 0
intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
ctxt 1990473
btime 1062191376
@@ -843,7 +848,8 @@
different kinds of work. Time units are in USER_HZ (typically hundredths of a
second). The meanings of the columns are as follows, from left to right:
-- user: normal processes executing in user mode
+- user: normal processes executing in user mode (includes guest time below so
+ that guest-unaware applications do not lose time)
- nice: niced processes executing in user mode
- system: processes executing in kernel mode
- idle: twiddling thumbs
@@ -851,6 +857,7 @@
- irq: servicing interrupts
- softirq: servicing softirqs
- steal: involuntary wait
+- guest: time used to run a virtual CPU
The "intr" line gives counts of interrupts serviced since boot time, for each
of the possible system interrupts. The first column is the total of all
Le mardi 24 juin 2008 à 22:43 +1000, AP a écrit :
> Git patch 5e84cfde51cf303d368fcb48f22059f37b3872de introduced a new
> field to /proc/stat that represents guest (virtual cpu) time.
>
> Git patch 9ac52315d4cf5f561f36dabaf0720c00d3553162 introduced the same
> to /proc/<pid>/stat along with a guest time of the tasks children.
>
> The patch below adds descriptions of these fields to the procfs
> documentation included in the kernel.
>
> Signed-Off-By: Andrew P <[email protected]>
It looks good to me.
Laurent
> diff -aur linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt
> --- linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt 2008-06-23 22:27:13.000000000 +1000
> +++ linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt 2008-06-24 22:16:53.000000000 +1000
> @@ -210,9 +210,9 @@
> cmin_flt number of minor faults with child's
> maj_flt number of major faults
> cmaj_flt number of major faults with child's
> - utime user mode jiffies
> + utime user mode jiffies (including gtime below*)
> stime kernel mode jiffies
> - cutime user mode jiffies with child's
> + cutime user mode jiffies with child's (including cgtime below*)
> cstime kernel mode jiffies with child's
> priority priority level
> nice nice level
> @@ -239,6 +239,11 @@
> rt_priority realtime priority
> policy scheduling policy (man sched_setscheduler)
> blkio_ticks time spent waiting for block IO
> + gtime guest (virtual CPU) CPU time in jiffies
> + cgtime guests' children's CPU time in jiffies
> +
> +* gtime and cgtime are included in these values so that applications that are
> + not aware of these fields do not lose time in their calculations.
> ..............................................................................
>
>
> @@ -828,9 +833,9 @@
> since the system first booted. For a quick look, simply cat the file:
>
> > cat /proc/stat
> - cpu 2255 34 2290 22625563 6290 127 456 0
> - cpu0 1132 34 1441 11311718 3675 127 438 0
> - cpu1 1123 0 849 11313845 2614 0 18 0
> + cpu 2255 34 2290 22625563 6290 127 456 0 0
> + cpu0 1132 34 1441 11311718 3675 127 438 0 0
> + cpu1 1123 0 849 11313845 2614 0 18 0 0
> intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
> ctxt 1990473
> btime 1062191376
> @@ -843,7 +848,8 @@
> different kinds of work. Time units are in USER_HZ (typically hundredths of a
> second). The meanings of the columns are as follows, from left to right:
>
> -- user: normal processes executing in user mode
> +- user: normal processes executing in user mode (includes guest time below so
> + that guest-unaware applications do not lose time)
> - nice: niced processes executing in user mode
> - system: processes executing in kernel mode
> - idle: twiddling thumbs
> @@ -851,6 +857,7 @@
> - irq: servicing interrupts
> - softirq: servicing softirqs
> - steal: involuntary wait
> +- guest: time used to run a virtual CPU
>
> The "intr" line gives counts of interrupts serviced since boot time, for each
> of the possible system interrupts. The first column is the total of all
>
--
------------- [email protected] ---------------
"The best way to predict the future is to invent it."
- Alan Kay
On Tue, Jun 24, 2008 at 2:43 PM, AP <[email protected]> wrote:
> Git patch 5e84cfde51cf303d368fcb48f22059f37b3872de introduced a new
> field to /proc/stat that represents guest (virtual cpu) time.
>
> Git patch 9ac52315d4cf5f561f36dabaf0720c00d3553162 introduced the same
> to /proc/<pid>/stat along with a guest time of the tasks children.
>
> The patch below adds descriptions of these fields to the procfs
> documentation included in the kernel.
>
> Signed-Off-By: Andrew P <[email protected]>
>
> diff -aur linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt
> --- linux-2.6.26-rc7-git2.orig/Documentation/filesystems/proc.txt 2008-06-23 22:27:13.000000000 +1000
> +++ linux-2.6.26-rc7-git2/Documentation/filesystems/proc.txt 2008-06-24 22:16:53.000000000 +1000
> @@ -210,9 +210,9 @@
> cmin_flt number of minor faults with child's
> maj_flt number of major faults
> cmaj_flt number of major faults with child's
> - utime user mode jiffies
> + utime user mode jiffies (including gtime below*)
> stime kernel mode jiffies
> - cutime user mode jiffies with child's
> + cutime user mode jiffies with child's (including cgtime below*)
> cstime kernel mode jiffies with child's
> priority priority level
> nice nice level
> @@ -239,6 +239,11 @@
> rt_priority realtime priority
> policy scheduling policy (man sched_setscheduler)
> blkio_ticks time spent waiting for block IO
> + gtime guest (virtual CPU) CPU time in jiffies
> + cgtime guests' children's CPU time in jiffies
> +
> +* gtime and cgtime are included in these values so that applications that are
> + not aware of these fields do not lose time in their calculations.
> ..............................................................................
>
>
> @@ -828,9 +833,9 @@
> since the system first booted. For a quick look, simply cat the file:
>
> > cat /proc/stat
> - cpu 2255 34 2290 22625563 6290 127 456 0
> - cpu0 1132 34 1441 11311718 3675 127 438 0
> - cpu1 1123 0 849 11313845 2614 0 18 0
> + cpu 2255 34 2290 22625563 6290 127 456 0 0
> + cpu0 1132 34 1441 11311718 3675 127 438 0 0
> + cpu1 1123 0 849 11313845 2614 0 18 0 0
> intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
> ctxt 1990473
> btime 1062191376
> @@ -843,7 +848,8 @@
> different kinds of work. Time units are in USER_HZ (typically hundredths of a
> second). The meanings of the columns are as follows, from left to right:
>
> -- user: normal processes executing in user mode
> +- user: normal processes executing in user mode (includes guest time below so
> + that guest-unaware applications do not lose time)
> - nice: niced processes executing in user mode
> - system: processes executing in kernel mode
> - idle: twiddling thumbs
> @@ -851,6 +857,7 @@
> - irq: servicing interrupts
> - softirq: servicing softirqs
> - steal: involuntary wait
> +- guest: time used to run a virtual CPU
>
> The "intr" line gives counts of interrupts serviced since boot time, for each
> of the possible system interrupts. The first column is the total of all
Acked-by: Michael Kerrisk <[email protected]>