Hi--
On 1/27/23 15:46, Shuah Khan wrote:
> Add a new section to the admin-guide with information of interest to
> application developers and system integrators doing analysis of the
> Linux kernel for safety critical applications.
>
> This section will contain documents supporting analysis of kernel
> interactions with applications, and key kernel subsystems expectations.
>
> Add a new workload-tracing document to this new section.
>
> Signed-off-by: Shefali Sharma <sshefali021@xxxxxxxxx>
> Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes since v1:
> - Addressed review comments on v1 on long lines, rst syntax, license
>
> Documentation/admin-guide/index.rst | 11 +
> .../admin-guide/workload-tracing.rst | 591 ++++++++++++++++++
> 2 files changed, 602 insertions(+)
> create mode 100644 Documentation/admin-guide/workload-tracing.rst
>
> diff --git a/Documentation/admin-guide/workload-tracing.rst b/Documentation/admin-guide/workload-tracing.rst
> new file mode 100644
> index 000000000000..43753f3ea915
> --- /dev/null
> +++ b/Documentation/admin-guide/workload-tracing.rst
> @@ -0,0 +1,591 @@
> +.. SPDX-License-Identifier: (GPL-2.0+ OR CC-BY-4.0)
> +
> +What is perf and how do we use it?
> +====================================
> +
> +Perf is an analysis tool based on Linux 2.6+ systems, which abstracts the
> +CPU hardware difference in performance measurement in Linux, and provides
> +a simple command line interface. Perf is based on the perf_events interface
> +exported by the kernel. It is very useful for profiling the system and
> +finding performance bottlenecks in an application.
> +
> +If you haven't already checkout the Linux mainline repository, you can do
checked out
> +so and then build kernel and perf tool: ::
> +
> + git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux
> + cd linux
> + make -j3 all
> + cd tools/perf
> + make
> +
> +Note: The perf command can be built without building the kernel in the
> +repo and can be run on older kernels. However matching the kernel and
preferably "repository"
> +perf revisions gives more accurate information on the subsystem usage.
> +
> +We used perf stat and perf bench options. For a detailed information on the
> +perf tool, run perf -h.
> +
Fix table line below:
> +Tracing paxtest kiddie workload
> +-------------------------------
> +
> +Run the following command to trace paxtest kiddie workload: ::
> +
> + strace -c paxtest kiddie
> +
> +**System Calls made by the workload:**
> +
> +The following table shows you the system calls, number of times the system
> +call was invoked, and the Linux subsystem they fall under.
> +
> ++-------------------+-----------+-----------------+----------------------+
> +| System Call | # calls | Linux Subsystem | System Call (API) |
> ++===================+===========+=================+======================+
> +| read | 3 | Filesystem | sys_read() |
> ++-------------------+-----------+-----------------+----------------------+
> +| write | 11 | Filesystem | sys_write() |
> ++-------------------+-----------+-----------------+----------------------+
> +| close | 41 | Filesystem | sys_close() |
> ++-------------------+-----------+-----------------+----------------------+
> +| stat | 24 | Filesystem | sys_stat() |
> ++-------------------+-----------+-----------------+----------------------+
> +| fstat | 2 | Filesystem | sys_fstat() |
> ++-------------------+-----------+-----------------+----------------------+
> +| pread64 | 6 | Filesystem | sys_pread64() |
> ++-------------------+-----------+-----------------+----------------------+
> +| access | 1 | Filesystem | sys_access() |
> ++-------------------+-----------+-----------------+----------------------+
> +| pipe | 1 | Filesystem | sys_pipe() |
> ++-------------------+-----------+-----------------+----------------------+
> +| dup2 | 24 | Filesystem | sys_dup2() |
> ++-------------------+-----------+-----------------+----------------------+
> +| execve | 1 | Filesystem | sys_execve() |
> ++-------------------+-----------+-----------------+----------------------+
> +| fcntl | 26 | Filesystem | sys_fcntl() |
> ++-------------------+-----------+-----------------+----------------------+
> +| openat | 14 | Filesystem | sys_openat() |
> ++-------------------+-----------+-----------------+----------------------+
> +| rt_sigaction | 7 | Signal | sys_rt_sigaction() |
> ++-------------------+-----------+-----------------+----------------------+
> +| rt_sigreturn | 38 | Signal | sys_rt_sigreturn() |
> ++-------------------+-----------+-----------------+----------------------+
> +| clone | 38 | Process Mgmt. | sys_clone() |
> ++-------------------+-----------+-----------------+----------------------+
> +| wait4 | 44 | Time | sys_wait4() |
> ++-------------------+-----------+-----------------+----------------------+
> +| mmap | 7 | Memory Mgmt. | sys_mmap() |
> ++-------------------+-----------+-----------------+----------------------+
> +| mprotect | 3 | Memory Mgmt. | sys_mprotect() |
> ++-------------------+-----------+-----------------+----------------------+
> +| munmap | 1 | Memory Mgmt. | sys_munmap() |
> ++-------------------+-----------+-----------------+----------------------+
> +| brk | 3 | Memory Mgmt. | sys_brk() |
> ++-------------------+-----------+-----------------+----------------------+
> +| getpid | 1 | Process Mgmt. | sys_getpid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| getuid | 1 | Process Mgmt. | sys_getuid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| getgid | 1 | Process Mgmt. | sys_getgid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| geteuid | 2 | Process Mgmt. | sys_geteuid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| getegid | 1 | Process Mgmt. | sys_getegid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| getppid | 1 | Process Mgmt. | sys_getppid() |
> ++-------------------+-----------+-----------------+----------------------+
> +| arch_prctl | 2 | Process Mgmt. | sys_arch_prctl() |
> ++-------------------+-----------+-----------------+----------------------+
> +
> +Conclusion
> +==========
> +
> +This document is intended to be used as a guide on how to gather fine
> +grained information on the resources in use by workloads using strace.
fine-grained
Thanks.
--
~Randy
