diff options
Diffstat (limited to 'linux-basics/linux-processes/pres_linux-processes_en.tex')
| -rw-r--r-- | linux-basics/linux-processes/pres_linux-processes_en.tex | 70 |
1 files changed, 27 insertions, 43 deletions
diff --git a/linux-basics/linux-processes/pres_linux-processes_en.tex b/linux-basics/linux-processes/pres_linux-processes_en.tex index a23a881..8d47f98 100644 --- a/linux-basics/linux-processes/pres_linux-processes_en.tex +++ b/linux-basics/linux-processes/pres_linux-processes_en.tex @@ -137,7 +137,7 @@ renice [-n] prio -u|--user user [.. user] \frametitle{SCHED\_IDLE and SCHED\_BATCH} \begin{itemize} \item SCHED\_BATCH: The scheduler will always assume the process to be CPU -intensive and therefor will apply a penalty when calculating the dynamic +intensive and therefore will apply a penalty when calculating the dynamic priority. \item SCHED\_IDLE: For very low prio processes. Even the nice value is ignored. The resulting priority will be \textbf{below} SCHED\_OTHER and SCHED\_BATCH @@ -261,8 +261,8 @@ $ cat /proc/irq/default_smp_affinity # Set default IRQ affinity to CPU0 $ echo 1 > /proc/irq/default_smp_affinity -# Set affinity for specific IRQ to CPU1 -$ echo 2 > /proc/irq/ +# Set affinity for IRQ19 to CPU1 +$ echo 2 > /proc/irq/19/smp_affinity \end{verbatim} \end{frame} @@ -278,50 +278,37 @@ CPU time, a specific set of CPUs, ... \begin{frame}[fragile] \frametitle{Using CGROUPS} \begin{verbatim} -$ mount -t cgroup -o defaults none /sys/fs/cgroup +$ mount -t cgroup -o cpu,cpuacct none /sys/fs/cgroup/cpu,cpuacct + +$ mount -t cgroup -o cpuset none /sys/fs/cgroup/cpuset \end{verbatim} \end{frame} \begin{frame}[fragile] \frametitle{CGROUPS: Creating new groups} \begin{verbatim} -$ cd /sys/fs/cgroup - -$ mkdir group_01 +$ mkdir /sys/fs/cgroup/cpu,cpuacct/group_nice -$ mkdir group_02 +$ mkdir /sys/fs/cgroup/cpuset/group_cpu0only \end{verbatim} \end{frame} \begin{frame}[fragile] \frametitle{CGROUPS: Setting up groups} \begin{verbatim} -$ cd group_01 - -# Set allowed CPUs -$ echo 0 > cpuset.cpus - -# Set allowed memory nodes -$ echo 0 > cpuset.mems - # Limit CPU time -$ echo 100 > cpu.shares +$ echo 100 > /sys/fs/cgroup/cpu,cpuacct/group_nice/cpu.shares \end{verbatim} \end{frame} \begin{frame}[fragile] \frametitle{CGROUPS: Setting up groups} \begin{verbatim} -$ cd group_02 - # Set allowed CPUs -$ echo 0 > cpuset.cpus +$ echo 0 > /sys/fs/cgroup/cpuset/group_cpu0only/cpuset.cpus # Set allowed memory nodes -$ echo 0 > cpuset.mems - -# Limit CPU time -$ echo 900 > cpu.shares +$ echo 0 > /sys/fs/cgroup/cpuset/group_cpu0only/cpuset.mems \end{verbatim} \end{frame} @@ -329,23 +316,22 @@ $ echo 900 > cpu.shares \frametitle{CGROUPS: Setting up groups} Open two shells. In shell 1 do: \begin{verbatim} -$ cd group_01 +# Add the current task to the cpu0only group +$ echo $$ > /sys/fs/cgroup/cpuset/group_cpu0only/tasks -# Add the current task to the group -$ echo $$ > tasks +# Add the current task to the nice group +$ echo $$ > /sys/fs/cgroup/cpu,cpuacct/group_nice/tasks # Create some noise -$ while [ 1 ]; do echo bla > /dev/null; done; +$ while true; do echo -n; done \end{verbatim} In shell 2: \begin{verbatim} -$ cd group_02 - -# Add the current task to the group -$ echo $$ > tasks +# Add the current task to the cpu0only group +$ echo $$ > /sys/fs/cgroup/cpuset/group_cpu0only/tasks # Create some noise -$ while [ 1 ]; do echo bla > /dev/null; done; +$ while true; do echo -n; done \end{verbatim} \end{frame} @@ -355,26 +341,24 @@ Now check the CPU usage with top \begin{verbatim} $ top [...] -4285 root 20 0 4708 1864 1524 R 89 0.2 8:59.68 bash -4152 root 20 0 4720 1904 1548 R 10 0.2 4:02.00 bash +PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND +871 root 20 0 22588 3480 3036 R 90.7 0.2 0:56.10 bash +872 root 20 0 22588 3484 3044 R 9.0 0.2 0:05.45 bash [...] \end{verbatim} \end{frame} \begin{frame}[fragile] \frametitle{CGROUPS: Who is using CGROUPS?} -SystemD uses CGROUPS! Boot with SystemD and check SysFS: +systemd uses CGROUPS! Boot with systemd and check SysFS: \begin{verbatim} -$ cd /sys/kernel/cgroup +$ cd /sys/fs/cgroup/systemd $ ls -blkio cpu cpuacct cpu,cpuacct cpuset devices freezer net_cls systemd +... system.slice ... user.slice -$ ls -1 /sys/fs/cgroup/cpu,cpuacct/system/ -cron.service -dbus.service -exim4.service -[...] +$ ls /sys/fs/cgroup/systemd/system.slice +... networking.service ... systemd-user-sessions.service ... \end{verbatim} \end{frame} |