tjh.dev
Linux kernel
============
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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.
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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Fix the argv ui browser code to correctly display more entries than fit
on the screen without crashing. The problem was some type confusion with
pointer types in the ->seek function. Do the argv arithmetic correctly
with char ** pointers. Also add some asserts to find overruns and limit
the display function correctly.
Then finally remove a workaround for this in the res sample browser.
Committer testing:
1) Resize the x terminal to have just some 5 lines
2) Use 'perf report --samples 1' to activate the sample browser options
in the menu
3) Press ENTER, this will cause the crash:
# perf report --samples 1
perf: Segmentation fault
-------- backtrace --------
perf[0x5a514a]
/lib64/libc.so.6(+0x385bf)[0x7f27281b55bf]
/lib64/libc.so.6(+0x161a67)[0x7f27282dea67]
/lib64/libslang.so.2(SLsmg_write_wrapped_string+0x82)[0x7f272874a0b2]
perf(ui_browser__argv_refresh+0x77)[0x5939a7]
perf[0x5924cc]
perf(ui_browser__run+0x39)[0x593449]
perf(ui__popup_menu+0x83)[0x5a5263]
perf[0x59f421]
perf(perf_evlist__tui_browse_hists+0x3a0)[0x5a3780]
perf(cmd_report+0x2746)[0x447136]
perf[0x4a95fe]
perf(main+0x61c)[0x42dc6c]
/lib64/libc.so.6(__libc_start_main+0xf2)[0x7f27281a1412]
perf(_start+0x2d)[0x42de9d]
#
After applying this patch no crash takes place in such situation.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-12-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Don't overflow array when the scripts directory is too large, or the
script file name is too long.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-11-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-9-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Now 'perf report' can show whole time periods with 'perf script', but
the user still has to find individual samples of interest manually.
It would be expensive and complicated to search for the right samples in
the whole perf file. Typically users only need to look at a small number
of samples for useful analysis.
Also the full scripts tend to show samples of all CPUs and all threads
mixed up, which can be very confusing on larger systems.
Add a new --samples option to save a small random number of samples per
hist entry.
Use a reservoir sample technique to select a representatve number of
samples.
Then allow browsing the samples using 'perf script' as part of the hist
entry context menu. This automatically adds the right filters, so only
the thread or cpu of the sample is displayed. Then we use less' search
functionality to directly jump the to the time stamp of the selected
sample.
It uses different menus for assembler and source display. Assembler
needs xed installed and source needs debuginfo.
Currently it only supports as many samples as fit on the screen due to
some limitations in the slang ui code.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311174605.GA29294@tassilo.jf.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The scripts menu traditionally only showed custom perf scripts.
Allow to run standard perf script with useful default options too.
- Normal perf script
- perf script with assembler (needs xed installed)
- perf script with source code output (needs debuginfo)
- perf script with custom arguments
Then we automatically select the right options to display the
information in the perf.data file.
For example with -b display branch contexts.
It's not easily possible to check for xed's existence in advance. perf
script usually gives sensible error messages when it's not available.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-7-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When using the time sort key, add new context menus to run scripts for
only the currently selected time range. Compute the correct range for
the selection add pass it as the --time option to perf script.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-6-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a time sort key to perf report to display samples for different time
quantums separately. This allows easier analysis of workloads that
change over time, and also will allow looking at the context of samples.
% perf record ...
% perf report --sort time,overhead,symbol --time-quantum 1ms --stdio
...
0.67% 277061.87300 [.] _dl_start
0.50% 277061.87300 [.] f1
0.50% 277061.87300 [.] f2
0.33% 277061.87300 [.] main
0.29% 277061.87300 [.] _dl_lookup_symbol_x
0.29% 277061.87300 [.] dl_main
0.29% 277061.87300 [.] do_lookup_x
0.17% 277061.87300 [.] _dl_debug_initialize
0.17% 277061.87300 [.] _dl_init_paths
0.08% 277061.87300 [.] check_match
0.04% 277061.87300 [.] _dl_count_modids
1.33% 277061.87400 [.] f1
1.33% 277061.87400 [.] f2
1.33% 277061.87400 [.] main
1.17% 277061.87500 [.] main
1.08% 277061.87500 [.] f1
1.08% 277061.87500 [.] f2
1.00% 277061.87600 [.] main
0.83% 277061.87600 [.] f1
0.83% 277061.87600 [.] f2
1.00% 277061.87700 [.] main
Committer notes:
Rename 'time' argument to hist_time() to htime to overcome this in older
distros:
cc1: warnings being treated as errors
util/hist.c: In function 'hist_time':
util/hist.c:251: error: declaration of 'time' shadows a global declaration
/usr/include/time.h:186: error: shadowed declaration is here
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-4-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The --cpu option only filtered samples. Filter other perf events, such
as COMM, FORK, SWITCH by the CPU too.
Reported-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20190311144502.15423-2-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get the changes in:
4effd28c1245 ("bridge: join all-snoopers multicast address")
That do not generate any changes in tools/ use of this file.
Silences this tools/perf build warning:
Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Lüssing <linus.luessing@c0d3.blue>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-ifpl634035266ho6wxuqgo81@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To get the changes in:
c8ce48f06503 ("asm-generic: Make time32 syscall numbers optional")
Silencing these tools/perf build warnings:
Warning: Kernel ABI header at 'tools/arch/arm64/include/uapi/asm/unistd.h' differs from latest version at 'arch/arm64/include/uapi/asm/unistd.h'
diff -u tools/arch/arm64/include/uapi/asm/unistd.h arch/arm64/include/uapi/asm/unistd.h
Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h
Test built it under the ubuntu:14.04.4-x-linaro-arm64 cross build
environment and looked at the syscall table at
/tmp/build/perf/arch/arm64/include/generated/asm/syscalls.c, looks ok.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/n/tip-e4w7ngsmkq48bd6st52ty2kb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes in 7948450d4556 ("x86/x32: use time64 versions of
sigtimedwait and recvmmsg"), that doesn't cause any change in behaviour
in tools/perf/ as it deals just with the x32 entries.
This silences this tools/perf build warning:
Warning: Kernel ABI header at 'tools/perf/arch/x86/entry/syscalls/syscall_64.tbl' differs from latest version at 'arch/x86/entry/syscalls/syscall_64.tbl'
diff -u tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-mqpvshayeqidlulx5qpioa59@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Introduce a printdate function to eliminate the repetitive use of
datetime.datetime.today() in the SQL exporting scripts.
Signed-off-by: Tony Jones <tonyj@suse.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/20190309000518.2438-5-tonyj@suse.de
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support both Python2 and Python3 in the export-to-sqlite.py script
The use of 'from __future__' implies the minimum supported Python2 version
is now v2.6
Signed-off-by: Tony Jones <tonyj@suse.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/20190309000518.2438-4-tonyj@suse.de
Signed-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support both Python2 and Python3 in the export-to-postgresql.py script.
The use of 'from __future__' implies the minimum supported Python2 version
is now v2.6
Signed-off-by: Tony Jones <tonyj@suse.de>
Link: http://lkml.kernel.org/r/20190309000518.2438-3-tonyj@suse.de
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Seeteena Thoufeek <s1seetee@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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