Ps command does not display the nice value for processes with the SCHED_BATCH
scheduler policy, only for SCHED_OTHER.
Boinc (http://boinc.berkeley.edu/) client runs project processing jobs on
Linux using SCHED_BATCH scheduler policy and nice value 19. The nice value
is not displayable by ps.
Steps to Reproduce:
1. Run process using SCHED_BATCH scheduler policy with nice value.
./test-schedbatch 18 &
2. Display process details:
ps -o pid,ppid,user,comm,cls,nice
Results before:
[mike@rockover c]$ ps -o pid,ppid,user,comm,cls,nice
PID PPID USER COMMAND CLS NI
18205 2540 mike bash TS 0
20552 18205 mike test-schedbatch B -
20553 18205 mike ps TS 0
[mike@rockover c]$ awk '{printf "%5d %-17s %1d %2d\n", $1, $2, $41, $19}'
/proc/20552/stat
20552 (test-schedbatch) 3 18
Results after this patch:
[mike@rockover c]$ ps -o pid,ppid,user,comm,cls,nice
PID PPID USER COMMAND CLS NI
18205 2540 mike bash TS 0
20552 18205 mike test-schedbatch B 18
20553 18205 mike ps TS 0
Additional info: Here is the fragment from the sched_setscheduler(2) manual
page on the subject:
SCHED_BATCH: Scheduling batch processes
(Since Linux 2.6.16.) SCHED_BATCH can only be used at static
priority 0. This policy is similar to SCHED_OTHER in that it
schedules the process according to its dynamic priority (based on the
nice value). The difference is that this policy will cause the
scheduler to always assume that the process is CPU-intensive.
Consequently, the scheduler will apply a small scheduling penalty with
respect to wakeup behaviour, so that this process is mildly disfavored
in scheduling decisions.
This policy is useful for workloads that are noninteractive, but do
not want to lower their nice value, and for workloads that want a
determin- istic scheduling policy without interactivity causing extra
preemptions (between the workload's tasks).
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=741090
Acked-by: Jaromir Capik <jcapik@redhat.com>
Acked-by: Sami Kerola <kerolasa@iki.fi>
Signed-off-by: Mike Fleetwood <mike.fleetwood@googlemail.com>
This patch mostly reorganizes include files and eliminates
some useless trailing whitespace.
It also adopts the standard procps-ng unconditional approach
to nls initialization.
Fix few compiler warnings. Some of these warnings appeared multiple
times, and the listing bellow is more about which sort of errors
where fixed.
devname.c:87:12: warning: comparison of integers of different signs: 'int' and 'unsigned long'
output.c:389:36: warning: passing 'char **const' to parameter of type 'const char *const restrict *' discards qualifiers in nested pointer types
output.c:611:31: warning: comparison of integers of different signs: 'const unsigned long' and 'int'
stacktrace.c:33:37: warning: unused parameter 'signum'
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Means we do not follow SCO but less confusion.
A patch from Debian.
Bug-Debian: http://bugs.debian.org/541061
Backported-by: Sami Kerola <kerolasa@iki.fi>
ps program
. etimes added for ELAPSED expressed in seconds
. time_t used in place of former unsigned long
top program
. corrected scroll message bug when 'x' toggle on
. fixed forest view potential missing libflags bug
. improved 'k' default signal invocation logic
. enhanced logic for %CPU maximums displayed
. made signal handling more robust and efficient
ps
. added tgid support
. made process/task naming consistent
top
. added tgid support
. standardized pid related width logic
documents
. added tgid to ps & top man documents
library
. fixed OOMEM_ENABLE readtask bug
. corrected header typo for tgid
Library changes
readproc
. added readeither to more efficiently
fill both process and thread proc_t
. added readproctab3, uses readeither
. included task path support in:
fill_cgroup_cvt, fill_cmdline_cvt,
read_unvectored
. QUICK_THREADS #define allows copying
process info vs. repeatedly reading
. simple_nexttid no longer values ppid
. path var made non-static in readtask
. documented 'proc_data_t' in .h file
. tweaked some c comments & formatting
library.map
. added new readeither, readproctab3
Program changes
ps
. exploits readproctab3 where possible
. improved args/comm compliance
top
. exploits readeither
Library changes
readproc
. added support for supplementary groups
. eliminated 2 potential mem leak sources
. shortcut used for multi-threaded str
vectors & ptrs was obsoleted
. freeing of proc_t related dynamic
memory now rests with the library
. standardized/normalized many c comments
sysinfo
. corrected note regarding glibc & cpuinfo
library.map
. made the visible freeproc accessable
Program changes
pmap
. initialized buffer for new readproc i/f
. eliminated now obsolete free() call
ps
. added width aware supgrp support
. initialized buffers for new readproc i/f
. eliminated now obsolete free() calls
top
. added supgrp support as variable width
. eliminated now obsolete free() calls
. expoilted library freeproc function
. corrected -h|v args text & spacing
. updated some c comments
Documentation changes
ps.1
. added supgid and supgrp
top.1
. added supgid and supgrp
. addition of above required renumbering
many fields in section 3a. DESCRIPTIONS
Library Changes
. added PROC_EDITCMDLCVT flag
. added an internal (static) fill_cmdline_cvt function:
- reads and "escapes" /proc/#/cmdline
- returns result as a single string in a single vector
- callers are guaranteed a cmdline (no more NULL)
. added vectorize_this_str function, exploited by
fill_cgroup_cvt, fill_cmdline_cvt
. generalized read_cmdline function as read_unvectored, now
exploited by fill_cgroup_cvt, fill_cmdline_cvt, read_cmdline
( cgroup and cmdline no longer need be converted to string )
( vectors before being transformed to final representation )
. fixed bug regarding skipped group numbers (when enabled)
. escape_str made responsible for all single byte translation
with distinction between control chars + other unprintable
. added escaped_copy function for already escaped strings
. reorganized parts of proc_t to restore formatting standards
( displacement changes shouldn't matter with new version # )
. former ZAP_SUSEONLY #define now OOMEM_ENABLE
. added to library.map: escaped_copy; read_cmdline
Top Program Changes
. exploited the new PROC_EDITCMDLCVT provision
. eliminated now obsolete #include "proc/escape.h"
. changed the P_WCH display format if no kernel symbol table
. fixed very old bug in lflgs for out-of-view sort fields
. former ZAP_SUSEONLY #define now OOMEM_ENABLE
Ps Program Changes
. exploited the new PROC_EDITCMDLCVT provision
. exploited the new escaped_copy function
. consolidated pr_args and pr_comm into pr_argcom
Signed-off-by: Jan Görig <jgorig@redhat.com>
Read the time of system boot from /proc/stat (entry: btime) instead
of computing it as the difference between the current time and the
uptime. This is the only way to get a consistent result which won't
possibly change from one run to the next.
The problems with the original code were:
* Both the current time and the uptime are rounded down to the second,
but the system doesn't boot on an integer second value so they do not
tick at the same moment. Thus, the rounding errors can cause a one
second difference from one run to the next.
* We can't read the uptime and the current time at the exact same moment
anyway, so the time difference we compute is bound to be inaccurate.
Bug-Redhat: https://bugzilla.redhat.com/show_bug.cgi?id=222251
Author: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Craig Small <csmall@debian.org>
