72363540c0
Support multiprobe event if the event is based on function and lines and
kernel supports it. In this case, perf probe creates the first probe
with an event, and tries to append following probes on that event, since
those probes must be on the same source code line.
Before this patch;
# perf probe -a vfs_read:18
Added new events:
probe:vfs_read_L18 (on vfs_read:18)
probe:vfs_read_L18_1 (on vfs_read:18)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_read_L18_1 -aR sleep 1
#
After this patch (on multiprobe supported kernel)
# perf probe -a vfs_read:18
Added new events:
probe:vfs_read_L18 (on vfs_read:18)
probe:vfs_read_L18 (on vfs_read:18)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_read_L18 -aR sleep 1
#
Committer testing:
On a kernel that doesn't support multiprobe events, after this patch:
# uname -a
Linux quaco 5.3.8-200.fc30.x86_64 #1 SMP Tue Oct 29 14:46:22 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
# grep append /sys/kernel/debug/tracing/README
be modified by appending '.descending' or '.ascending' to a
can be modified by appending any of the following modifiers
#
# perf probe -a vfs_read:18
Added new events:
probe:vfs_read_L18 (on vfs_read:18)
probe:vfs_read_L18_1 (on vfs_read:18)
You can now use it in all perf tools, such as:
perf record -e probe:vfs_read_L18_1 -aR sleep 1
# perf probe -l
probe:vfs_read_L18 (on vfs_read:18@fs/read_write.c)
probe:vfs_read_L18_1 (on vfs_read:18@fs/read_write.c)
#
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: http://lore.kernel.org/lkml/157406475010.24476.586290752591512351.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.