<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/tools/scripts, branch v5.12-rc5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge tag 'perf-tools-for-v5.12-2020-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux</title>
<updated>2021-02-22T21:59:43+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-02-22T21:59:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3a36281a17199737b468befb826d4a23eb774445'/>
<id>3a36281a17199737b468befb826d4a23eb774445</id>
<content type='text'>
Pull perf tool updates from Arnaldo Carvalho de Melo:
 "New features:

   - Support instruction latency in 'perf report', with both memory
     latency (weight) and instruction latency information, users can
     locate expensive load instructions and understand time spent in
     different stages.

   - Extend 'perf c2c' to display the number of loads which were blocked
     by data or address conflict.

   - Add 'perf stat' support for L2 topdown events in systems such as
     Intel's Sapphire rapids server.

   - Add support for PERF_SAMPLE_CODE_PAGE_SIZE in various tools, as a
     sort key, for instance:

        perf report --stdio --sort=comm,symbol,code_page_size

   - New 'perf daemon' command to run long running sessions while
     providing a way to control the enablement of events without
     restarting a traditional 'perf record' session.

   - Enable counting events for BPF programs in 'perf stat' just like
     for other targets (tid, cgroup, cpu, etc), e.g.:

        # perf stat -e ref-cycles,cycles -b 254 -I 1000
           1.487903822            115,200      ref-cycles
           1.487903822             86,012      cycles
           2.489147029             80,560      ref-cycles
           2.489147029             73,784      cycles
        ^C

     The example above counts 'cycles' and 'ref-cycles' of BPF program
     of id 254. It is similar to bpftool-prog-profile command, but more
     flexible.

   - Support the new layout for PERF_RECORD_MMAP2 to carry the DSO
     build-id using infrastructure generalised from the eBPF subsystem,
     removing the need for traversing the perf.data file to collect
     build-ids at the end of 'perf record' sessions and helping with
     long running sessions where binaries can get replaced in updates,
     leading to possible mis-resolution of symbols.

   - Support filtering by hex address in 'perf script'.

   - Support DSO filter in 'perf script', like in other perf tools.

   - Add namespaces support to 'perf inject'

   - Add support for SDT (Dtrace Style Markers) events on ARM64.

  perf record:

   - Fix handling of eventfd() when draining a buffer in 'perf record'.

   - Improvements to the generation of metadata events for pre-existing
     threads (mmaps, comm, etc), speeding up the work done at the start
     of system wide or per CPU 'perf record' sessions.

  Hardware tracing:

   - Initial support for tracing KVM with Intel PT.

   - Intel PT fixes for IPC

   - Support Intel PT PSB (synchronization packets) events.

   - Automatically group aux-output events to overcome --filter syntax.

   - Enable PERF_SAMPLE_DATA_SRC on ARMs SPE.

   - Update ARM's CoreSight hardware tracing OpenCSD library to v1.0.0.

  perf annotate TUI:

   - Fix handling of 'k' ("show line number") hotkey

   - Fix jump parsing for C++ code.

  perf probe:

   - Add protection to avoid endless loop.

  cgroups:

   - Avoid reading cgroup mountpoint multiple times, caching it.

   - Fix handling of cgroup v1/v2 in mixed hierarchy.

  Symbol resolving:

   - Add OCaml symbol demangling.

   - Further fixes for handling PE executables when using perf with Wine
     and .exe/.dll files.

   - Fix 'perf unwind' DSO handling.

   - Resolve symbols against debug file first, to deal with artifacts
     related to LTO.

   - Fix gap between kernel end and module start on powerpc.

  Reporting tools:

   - The DSO filter shouldn't show samples in unresolved maps.

   - Improve debuginfod support in various tools.

  build ids:

   - Fix 16-byte build ids in 'perf buildid-cache', add a 'perf test'
     entry for that case.

  perf test:

   - Support for PERF_SAMPLE_WEIGHT_STRUCT.

   - Add test case for PERF_SAMPLE_CODE_PAGE_SIZE.

   - Shell based tests for 'perf daemon's commands ('start', 'stop,
     'reconfig', 'list', etc).

   - ARM cs-etm 'perf test' fixes.

   - Add parse-metric memory bandwidth testcase.

  Compiler related:

   - Fix 'perf probe' kretprobe issue caused by gcc 11 bug when used
     with -fpatchable-function-entry.

   - Fix ARM64 build with gcc 11's -Wformat-overflow.

   - Fix unaligned access in sample parsing test.

   - Fix printf conversion specifier for IP addresses on arm64, s390 and
     powerpc.

  Arch specific:

   - Support exposing Performance Monitor Counter SPRs as part of
     extended regs on powerpc.

   - Add JSON 'perf stat' metrics for ARM64's imx8mp, imx8mq and imx8mn
     DDR, fix imx8mm ones.

   - Fix common and uarch events for ARM64's A76 and Ampere eMag"

* tag 'perf-tools-for-v5.12-2020-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (148 commits)
  perf buildid-cache: Don't skip 16-byte build-ids
  perf buildid-cache: Add test for 16-byte build-id
  perf symbol: Remove redundant libbfd checks
  perf test: Output the sub testing result in cs-etm
  perf test: Suppress logs in cs-etm testing
  perf tools: Fix arm64 build error with gcc-11
  perf intel-pt: Add documentation for tracing virtual machines
  perf intel-pt: Split VM-Entry and VM-Exit branches
  perf intel-pt: Adjust sample flags for VM-Exit
  perf intel-pt: Allow for a guest kernel address filter
  perf intel-pt: Support decoding of guest kernel
  perf machine: Factor out machine__idle_thread()
  perf machine: Factor out machines__find_guest()
  perf intel-pt: Amend decoder to track the NR flag
  perf intel-pt: Retain the last PIP packet payload as is
  perf intel_pt: Add vmlaunch and vmresume as branches
  perf script: Add branch types for VM-Entry and VM-Exit
  perf auxtrace: Automatically group aux-output events
  perf test: Fix unaligned access in sample parsing test
  perf tools: Support arch specific PERF_SAMPLE_WEIGHT_STRUCT processing
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf tool updates from Arnaldo Carvalho de Melo:
 "New features:

   - Support instruction latency in 'perf report', with both memory
     latency (weight) and instruction latency information, users can
     locate expensive load instructions and understand time spent in
     different stages.

   - Extend 'perf c2c' to display the number of loads which were blocked
     by data or address conflict.

   - Add 'perf stat' support for L2 topdown events in systems such as
     Intel's Sapphire rapids server.

   - Add support for PERF_SAMPLE_CODE_PAGE_SIZE in various tools, as a
     sort key, for instance:

        perf report --stdio --sort=comm,symbol,code_page_size

   - New 'perf daemon' command to run long running sessions while
     providing a way to control the enablement of events without
     restarting a traditional 'perf record' session.

   - Enable counting events for BPF programs in 'perf stat' just like
     for other targets (tid, cgroup, cpu, etc), e.g.:

        # perf stat -e ref-cycles,cycles -b 254 -I 1000
           1.487903822            115,200      ref-cycles
           1.487903822             86,012      cycles
           2.489147029             80,560      ref-cycles
           2.489147029             73,784      cycles
        ^C

     The example above counts 'cycles' and 'ref-cycles' of BPF program
     of id 254. It is similar to bpftool-prog-profile command, but more
     flexible.

   - Support the new layout for PERF_RECORD_MMAP2 to carry the DSO
     build-id using infrastructure generalised from the eBPF subsystem,
     removing the need for traversing the perf.data file to collect
     build-ids at the end of 'perf record' sessions and helping with
     long running sessions where binaries can get replaced in updates,
     leading to possible mis-resolution of symbols.

   - Support filtering by hex address in 'perf script'.

   - Support DSO filter in 'perf script', like in other perf tools.

   - Add namespaces support to 'perf inject'

   - Add support for SDT (Dtrace Style Markers) events on ARM64.

  perf record:

   - Fix handling of eventfd() when draining a buffer in 'perf record'.

   - Improvements to the generation of metadata events for pre-existing
     threads (mmaps, comm, etc), speeding up the work done at the start
     of system wide or per CPU 'perf record' sessions.

  Hardware tracing:

   - Initial support for tracing KVM with Intel PT.

   - Intel PT fixes for IPC

   - Support Intel PT PSB (synchronization packets) events.

   - Automatically group aux-output events to overcome --filter syntax.

   - Enable PERF_SAMPLE_DATA_SRC on ARMs SPE.

   - Update ARM's CoreSight hardware tracing OpenCSD library to v1.0.0.

  perf annotate TUI:

   - Fix handling of 'k' ("show line number") hotkey

   - Fix jump parsing for C++ code.

  perf probe:

   - Add protection to avoid endless loop.

  cgroups:

   - Avoid reading cgroup mountpoint multiple times, caching it.

   - Fix handling of cgroup v1/v2 in mixed hierarchy.

  Symbol resolving:

   - Add OCaml symbol demangling.

   - Further fixes for handling PE executables when using perf with Wine
     and .exe/.dll files.

   - Fix 'perf unwind' DSO handling.

   - Resolve symbols against debug file first, to deal with artifacts
     related to LTO.

   - Fix gap between kernel end and module start on powerpc.

  Reporting tools:

   - The DSO filter shouldn't show samples in unresolved maps.

   - Improve debuginfod support in various tools.

  build ids:

   - Fix 16-byte build ids in 'perf buildid-cache', add a 'perf test'
     entry for that case.

  perf test:

   - Support for PERF_SAMPLE_WEIGHT_STRUCT.

   - Add test case for PERF_SAMPLE_CODE_PAGE_SIZE.

   - Shell based tests for 'perf daemon's commands ('start', 'stop,
     'reconfig', 'list', etc).

   - ARM cs-etm 'perf test' fixes.

   - Add parse-metric memory bandwidth testcase.

  Compiler related:

   - Fix 'perf probe' kretprobe issue caused by gcc 11 bug when used
     with -fpatchable-function-entry.

   - Fix ARM64 build with gcc 11's -Wformat-overflow.

   - Fix unaligned access in sample parsing test.

   - Fix printf conversion specifier for IP addresses on arm64, s390 and
     powerpc.

  Arch specific:

   - Support exposing Performance Monitor Counter SPRs as part of
     extended regs on powerpc.

   - Add JSON 'perf stat' metrics for ARM64's imx8mp, imx8mq and imx8mn
     DDR, fix imx8mm ones.

   - Fix common and uarch events for ARM64's A76 and Ampere eMag"

* tag 'perf-tools-for-v5.12-2020-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (148 commits)
  perf buildid-cache: Don't skip 16-byte build-ids
  perf buildid-cache: Add test for 16-byte build-id
  perf symbol: Remove redundant libbfd checks
  perf test: Output the sub testing result in cs-etm
  perf test: Suppress logs in cs-etm testing
  perf tools: Fix arm64 build error with gcc-11
  perf intel-pt: Add documentation for tracing virtual machines
  perf intel-pt: Split VM-Entry and VM-Exit branches
  perf intel-pt: Adjust sample flags for VM-Exit
  perf intel-pt: Allow for a guest kernel address filter
  perf intel-pt: Support decoding of guest kernel
  perf machine: Factor out machine__idle_thread()
  perf machine: Factor out machines__find_guest()
  perf intel-pt: Amend decoder to track the NR flag
  perf intel-pt: Retain the last PIP packet payload as is
  perf intel_pt: Add vmlaunch and vmresume as branches
  perf script: Add branch types for VM-Entry and VM-Exit
  perf auxtrace: Automatically group aux-output events
  perf test: Fix unaligned access in sample parsing test
  perf tools: Support arch specific PERF_SAMPLE_WEIGHT_STRUCT processing
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>tools: Factor Clang, LLC and LLVM utils definitions</title>
<updated>2021-01-29T00:25:34+00:00</updated>
<author>
<name>Sedat Dilek</name>
<email>sedat.dilek@gmail.com</email>
</author>
<published>2021-01-28T01:50:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=211a741cd3e124bffdc13ee82e7e65f204e53f60'/>
<id>211a741cd3e124bffdc13ee82e7e65f204e53f60</id>
<content type='text'>
When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.

While looking into the source code I found duplicate assignments in misc tools
for the LLVM eco system, e.g. clang and llvm-objcopy.

Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include
file and add missing includes where needed. Honestly, I was inspired by the commit
c8a950d0d3b9 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").

I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1.

Build instructions:

[ make and make-options ]
MAKE="make V=1"
MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1"
MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"

[ clean-up ]
$MAKE $MAKE_OPTS -C tools/ clean

[ bpftool ]
$MAKE $MAKE_OPTS -C tools/bpf/bpftool/

[ perf ]
PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/

I was careful with respecting the user's wish to override custom compiler, linker,
GNU/binutils and/or LLVM utils settings.

Signed-off-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt; # tools/build and tools/perf
Link: https://lore.kernel.org/bpf/20210128015117.20515-1-sedat.dilek@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool.

While looking into the source code I found duplicate assignments in misc tools
for the LLVM eco system, e.g. clang and llvm-objcopy.

Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include
file and add missing includes where needed. Honestly, I was inspired by the commit
c8a950d0d3b9 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions").

I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1.

Build instructions:

[ make and make-options ]
MAKE="make V=1"
MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1"
MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole"

[ clean-up ]
$MAKE $MAKE_OPTS -C tools/ clean

[ bpftool ]
$MAKE $MAKE_OPTS -C tools/bpf/bpftool/

[ perf ]
PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/

I was careful with respecting the user's wish to override custom compiler, linker,
GNU/binutils and/or LLVM utils settings.

Signed-off-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt; # tools/build and tools/perf
Link: https://lore.kernel.org/bpf/20210128015117.20515-1-sedat.dilek@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>perf build: Support build BPF skeletons with perf</title>
<updated>2021-01-15T18:49:07+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2020-12-29T21:42:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fbcdaa1908e8f61aa56c71a1db9a9deb72110a9d'/>
<id>fbcdaa1908e8f61aa56c71a1db9a9deb72110a9d</id>
<content type='text'>
BPF programs are useful in perf to profile BPF programs.

BPF skeleton is by far the easiest way to write BPF tools. Enable
building BPF skeletons in util/bpf_skel. A dummy bpf skeleton is added.
More bpf skeletons will be added for different use cases.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20201229214214.3413833-3-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
BPF programs are useful in perf to profile BPF programs.

BPF skeleton is by far the easiest way to write BPF tools. Enable
building BPF skeletons in util/bpf_skel. A dummy bpf skeleton is added.
More bpf skeletons will be added for different use cases.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Link: http://lore.kernel.org/lkml/20201229214214.3413833-3-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools: Factor HOSTCC, HOSTLD, HOSTAR definitions</title>
<updated>2020-11-11T20:18:22+00:00</updated>
<author>
<name>Jean-Philippe Brucker</name>
<email>jean-philippe@linaro.org</email>
</author>
<published>2020-11-10T16:43:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c8a950d0d3b926a02c7b2e713850d38217cec3d1'/>
<id>c8a950d0d3b926a02c7b2e713850d38217cec3d1</id>
<content type='text'>
Several Makefiles in tools/ need to define the host toolchain variables.
Move their definition to tools/scripts/Makefile.include

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://lore.kernel.org/bpf/20201110164310.2600671-2-jean-philippe@linaro.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Several Makefiles in tools/ need to define the host toolchain variables.
Move their definition to tools/scripts/Makefile.include

Signed-off-by: Jean-Philippe Brucker &lt;jean-philippe@linaro.org&gt;
Signed-off-by: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://lore.kernel.org/bpf/20201110164310.2600671-2-jean-philippe@linaro.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2020-03-26T01:58:11+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2020-03-26T01:58:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9fb16955fb661945ddffce4504dcffbe55cd518a'/>
<id>9fb16955fb661945ddffce4504dcffbe55cd518a</id>
<content type='text'>
Overlapping header include additions in macsec.c

A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c

Overlapping test additions in selftests Makefile

Overlapping PCI ID table adjustments in iwlwifi driver.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Overlapping header include additions in macsec.c

A bug fix in 'net' overlapping with the removal of 'version'
string in ena_netdev.c

Overlapping test additions in selftests Makefile

Overlapping PCI ID table adjustments in iwlwifi driver.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpftool: Introduce "prog profile" command</title>
<updated>2020-03-09T23:04:07+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2020-03-09T17:32:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=47c09d6a9f6794caface4ad50930460b82d7c670'/>
<id>47c09d6a9f6794caface4ad50930460b82d7c670</id>
<content type='text'>
With fentry/fexit programs, it is possible to profile BPF program with
hardware counters. Introduce bpftool "prog profile", which measures key
metrics of a BPF program.

bpftool prog profile command creates per-cpu perf events. Then it attaches
fentry/fexit programs to the target BPF program. The fentry program saves
perf event value to a map. The fexit program reads the perf event again,
and calculates the difference, which is the instructions/cycles used by
the target program.

Example input and output:

  ./bpftool prog profile id 337 duration 3 cycles instructions llc_misses

        4228 run_cnt
     3403698 cycles                                              (84.08%)
     3525294 instructions   #  1.04 insn per cycle               (84.05%)
          13 llc_misses     #  3.69 LLC misses per million isns  (83.50%)

This command measures cycles and instructions for BPF program with id
337 for 3 seconds. The program has triggered 4228 times. The rest of the
output is similar to perf-stat. In this example, the counters were only
counting ~84% of the time because of time multiplexing of perf counters.

Note that, this approach measures cycles and instructions in very small
increments. So the fentry/fexit programs introduce noticeable errors to
the measurement results.

The fentry/fexit programs are generated with BPF skeletons. Therefore, we
build bpftool twice. The first time _bpftool is built without skeletons.
Then, _bpftool is used to generate the skeletons. The second time, bpftool
is built with skeletons.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/20200309173218.2739965-2-songliubraving@fb.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With fentry/fexit programs, it is possible to profile BPF program with
hardware counters. Introduce bpftool "prog profile", which measures key
metrics of a BPF program.

bpftool prog profile command creates per-cpu perf events. Then it attaches
fentry/fexit programs to the target BPF program. The fentry program saves
perf event value to a map. The fexit program reads the perf event again,
and calculates the difference, which is the instructions/cycles used by
the target program.

Example input and output:

  ./bpftool prog profile id 337 duration 3 cycles instructions llc_misses

        4228 run_cnt
     3403698 cycles                                              (84.08%)
     3525294 instructions   #  1.04 insn per cycle               (84.05%)
          13 llc_misses     #  3.69 LLC misses per million isns  (83.50%)

This command measures cycles and instructions for BPF program with id
337 for 3 seconds. The program has triggered 4228 times. The rest of the
output is similar to perf-stat. In this example, the counters were only
counting ~84% of the time because of time multiplexing of perf counters.

Note that, this approach measures cycles and instructions in very small
increments. So the fentry/fexit programs introduce noticeable errors to
the measurement results.

The fentry/fexit programs are generated with BPF skeletons. Therefore, we
build bpftool twice. The first time _bpftool is built without skeletons.
Then, _bpftool is used to generate the skeletons. The second time, bpftool
is built with skeletons.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Quentin Monnet &lt;quentin@isovalent.com&gt;
Acked-by: Yonghong Song &lt;yhs@fb.com&gt;
Link: https://lore.kernel.org/bpf/20200309173218.2739965-2-songliubraving@fb.com
</pre>
</div>
</content>
</entry>
<entry>
<title>tools: Let O= makes handle a relative path with -C option</title>
<updated>2020-03-06T20:08:28+00:00</updated>
<author>
<name>Masami Hiramatsu</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2020-03-06T18:32:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=be40920fbf1003c38ccdc02b571e01a75d890c82'/>
<id>be40920fbf1003c38ccdc02b571e01a75d890c82</id>
<content type='text'>
When I tried to compile tools/perf from the top directory with the -C
option, the O= option didn't work correctly if I passed a relative path:

  $ make O=BUILD -C tools/perf/
  make: Entering directory '/home/mhiramat/ksrc/linux/tools/perf'
    BUILD:   Doing 'make -j8' parallel build
  ../scripts/Makefile.include:4: *** O=/home/mhiramat/ksrc/linux/tools/perf/BUILD does not exist.  Stop.
  make: *** [Makefile:70: all] Error 2
  make: Leaving directory '/home/mhiramat/ksrc/linux/tools/perf'

The O= directory existence check failed because the check script ran in
the build target directory instead of the directory where I ran the make
command.

To fix that, once change directory to $(PWD) and check O= directory,
since the PWD is set to where the make command runs.

Fixes: c883122acc0d ("perf tools: Let O= makes handle relative paths")
Reported-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Michal Marek &lt;michal.lkml@markovi.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sasha Levin &lt;sashal@kernel.org&gt;
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158351957799.3363.15269768530697526765.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When I tried to compile tools/perf from the top directory with the -C
option, the O= option didn't work correctly if I passed a relative path:

  $ make O=BUILD -C tools/perf/
  make: Entering directory '/home/mhiramat/ksrc/linux/tools/perf'
    BUILD:   Doing 'make -j8' parallel build
  ../scripts/Makefile.include:4: *** O=/home/mhiramat/ksrc/linux/tools/perf/BUILD does not exist.  Stop.
  make: *** [Makefile:70: all] Error 2
  make: Leaving directory '/home/mhiramat/ksrc/linux/tools/perf'

The O= directory existence check failed because the check script ran in
the build target directory instead of the directory where I ran the make
command.

To fix that, once change directory to $(PWD) and check O= directory,
since the PWD is set to where the make command runs.

Fixes: c883122acc0d ("perf tools: Let O= makes handle relative paths")
Reported-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
Cc: Michal Marek &lt;michal.lkml@markovi.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sasha Levin &lt;sashal@kernel.org&gt;
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158351957799.3363.15269768530697526765.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf build: Do not use -Wshadow on gcc &lt; 4.8</title>
<updated>2019-07-23T12:04:54+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2019-07-19T18:34:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=39e7317e37f7f0be366d1201c283f968c17268da'/>
<id>39e7317e37f7f0be366d1201c283f968c17268da</id>
<content type='text'>
As it is too strict, see https://lkml.org/lkml/2006/11/28/253 and
https://gcc.gnu.org/gcc-4.8/changes.html, that takes into account
Linus's comments (search for Wshadow) for the reasoning about -Wshadow
not being interesting before gcc 4.8.

Acked-by: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lkml.kernel.org/r/20190719183417.GQ3624@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As it is too strict, see https://lkml.org/lkml/2006/11/28/253 and
https://gcc.gnu.org/gcc-4.8/changes.html, that takes into account
Linus's comments (search for Wshadow) for the reasoning about -Wshadow
not being interesting before gcc 4.8.

Acked-by: Andrii Nakryiko &lt;andrii.nakryiko@gmail.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lkml.kernel.org/r/20190719183417.GQ3624@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Kbuild: fix # escaping in .cmd files for future Make</title>
<updated>2018-04-10T15:03:02+00:00</updated>
<author>
<name>Rasmus Villemoes</name>
<email>linux@rasmusvillemoes.dk</email>
</author>
<published>2018-04-08T21:35:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9564a8cf422d7b58f6e857e3546d346fa970191e'/>
<id>9564a8cf422d7b58f6e857e3546d346fa970191e</id>
<content type='text'>
I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
already the objtool build broke with

orc_dump.c: In function ‘orc_dump’:
orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
  if (elf_getshdrnum(elf, &amp;nr_sections)) {

Turns out that with that new Make, the backslash was not removed, so cpp
didn't see a #include directive, grep found nothing, and
-DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.

Now, that new Make behaviour is documented in their NEWS file:

  * WARNING: Backward-incompatibility!
    Number signs (#) appearing inside a macro reference or function invocation
    no longer introduce comments and should not be escaped with backslashes:
    thus a call such as:
      foo := $(shell echo '#')
    is legal.  Previously the number sign needed to be escaped, for example:
      foo := $(shell echo '\#')
    Now this latter will resolve to "\#".  If you want to write makefiles
    portable to both versions, assign the number sign to a variable:
      C := \#
      foo := $(shell echo '$C')
    This was claimed to be fixed in 3.81, but wasn't, for some reason.
    To detect this change search for 'nocomment' in the .FEATURES variable.

This also fixes up the two make-cmd instances to replace # with $(pound)
rather than with \#. There might very well be other places that need
similar fixup in preparation for whatever future Make release contains
the above change, but at least this builds an x86_64 defconfig with the
new make.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I tried building using a freshly built Make (4.2.1-69-g8a731d1), but
already the objtool build broke with

orc_dump.c: In function ‘orc_dump’:
orc_dump.c:106:2: error: ‘elf_getshnum’ is deprecated [-Werror=deprecated-declarations]
  if (elf_getshdrnum(elf, &amp;nr_sections)) {

Turns out that with that new Make, the backslash was not removed, so cpp
didn't see a #include directive, grep found nothing, and
-DLIBELF_USE_DEPRECATED was wrongly put in CFLAGS.

Now, that new Make behaviour is documented in their NEWS file:

  * WARNING: Backward-incompatibility!
    Number signs (#) appearing inside a macro reference or function invocation
    no longer introduce comments and should not be escaped with backslashes:
    thus a call such as:
      foo := $(shell echo '#')
    is legal.  Previously the number sign needed to be escaped, for example:
      foo := $(shell echo '\#')
    Now this latter will resolve to "\#".  If you want to write makefiles
    portable to both versions, assign the number sign to a variable:
      C := \#
      foo := $(shell echo '$C')
    This was claimed to be fixed in 3.81, but wasn't, for some reason.
    To detect this change search for 'nocomment' in the .FEATURES variable.

This also fixes up the two make-cmd instances to replace # with $(pound)
rather than with \#. There might very well be other places that need
similar fixup in preparation for whatever future Make release contains
the above change, but at least this builds an x86_64 defconfig with the
new make.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=197847
Cc: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: remove tile port</title>
<updated>2018-03-16T09:56:03+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2018-03-09T13:13:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bb9d812643d8a121df7d614a2b9c60193a92deb0'/>
<id>bb9d812643d8a121df7d614a2b9c60193a92deb0</id>
<content type='text'>
The Tile architecture port was added by Chris Metcalf in 2010, and
maintained until early 2018 when he orphaned it due to his departure
from Mellanox, and nobody else stepped up to maintain it. The product
line is still around in the form of the BlueField SoC, but no longer
uses the Tile architecture.

There are also still products for sale with Tile-GX SoCs, notably the
Mikrotik CCR router family. The products all use old (linux-3.3) kernels
with lots of patches and won't be upgraded by their manufacturers. There
have been efforts to port both OpenWRT and Debian to these, but both
projects have stalled and are very unlikely to be continued in the future.

Given that we are reasonably sure that nobody is still using the port
with an upstream kernel any more, it seems better to remove it now while
the port is in a good shape than to let it bitrot for a few years first.

Cc: Chris Metcalf &lt;chris.d.metcalf@gmail.com&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Link: http://www.mellanox.com/page/npu_multicore_overview
Link: https://jenkins.debian.net/view/rebootstrap/job/rebootstrap_tilegx_gcc7/
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The Tile architecture port was added by Chris Metcalf in 2010, and
maintained until early 2018 when he orphaned it due to his departure
from Mellanox, and nobody else stepped up to maintain it. The product
line is still around in the form of the BlueField SoC, but no longer
uses the Tile architecture.

There are also still products for sale with Tile-GX SoCs, notably the
Mikrotik CCR router family. The products all use old (linux-3.3) kernels
with lots of patches and won't be upgraded by their manufacturers. There
have been efforts to port both OpenWRT and Debian to these, but both
projects have stalled and are very unlikely to be continued in the future.

Given that we are reasonably sure that nobody is still using the port
with an upstream kernel any more, it seems better to remove it now while
the port is in a good shape than to let it bitrot for a few years first.

Cc: Chris Metcalf &lt;chris.d.metcalf@gmail.com&gt;
Cc: John Paul Adrian Glaubitz &lt;glaubitz@physik.fu-berlin.de&gt;
Link: http://www.mellanox.com/page/npu_multicore_overview
Link: https://jenkins.debian.net/view/rebootstrap/job/rebootstrap_tilegx_gcc7/
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
