<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/perf, branch v6.18-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2025-10-11T17:51:14+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-10-11T17:51:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2f0a7504530c24f55daec7d2364d933bb1a1fa68'/>
<id>2f0a7504530c24f55daec7d2364d933bb1a1fa68</id>
<content type='text'>
Pull x86 cleanups from Borislav Petkov:

 - Simplify inline asm flag output operands now that the minimum
   compiler version supports the =@ccCOND syntax

 - Remove a bunch of AS_* Kconfig symbols which detect assembler support
   for various instruction mnemonics now that the minimum assembler
   version supports them all

 - The usual cleanups all over the place

* tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__
  x86/sgx: Use ENCLS mnemonic in &lt;kernel/cpu/sgx/encls.h&gt;
  x86/mtrr: Remove license boilerplate text with bad FSF address
  x86/asm: Use RDPKRU and WRPKRU mnemonics in &lt;asm/special_insns.h&gt;
  x86/idle: Use MONITORX and MWAITX mnemonics in &lt;asm/mwait.h&gt;
  x86/entry/fred: Push __KERNEL_CS directly
  x86/kconfig: Remove CONFIG_AS_AVX512
  crypto: x86 - Remove CONFIG_AS_VPCLMULQDQ
  crypto: X86 - Remove CONFIG_AS_VAES
  crypto: x86 - Remove CONFIG_AS_GFNI
  x86/kconfig: Drop unused and needless config X86_64_SMP
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 cleanups from Borislav Petkov:

 - Simplify inline asm flag output operands now that the minimum
   compiler version supports the =@ccCOND syntax

 - Remove a bunch of AS_* Kconfig symbols which detect assembler support
   for various instruction mnemonics now that the minimum assembler
   version supports them all

 - The usual cleanups all over the place

* tag 'x86_cleanups_for_v6.18_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm: Remove code depending on __GCC_ASM_FLAG_OUTPUTS__
  x86/sgx: Use ENCLS mnemonic in &lt;kernel/cpu/sgx/encls.h&gt;
  x86/mtrr: Remove license boilerplate text with bad FSF address
  x86/asm: Use RDPKRU and WRPKRU mnemonics in &lt;asm/special_insns.h&gt;
  x86/idle: Use MONITORX and MWAITX mnemonics in &lt;asm/mwait.h&gt;
  x86/entry/fred: Push __KERNEL_CS directly
  x86/kconfig: Remove CONFIG_AS_AVX512
  crypto: x86 - Remove CONFIG_AS_VPCLMULQDQ
  crypto: X86 - Remove CONFIG_AS_VAES
  crypto: x86 - Remove CONFIG_AS_GFNI
  x86/kconfig: Drop unused and needless config X86_64_SMP
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'perf-tools-for-v6.18-1-2025-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools</title>
<updated>2025-10-09T02:24:24+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-10-09T02:24:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ec714e371f22f716a04e6ecb2a24988c92b26911'/>
<id>ec714e371f22f716a04e6ecb2a24988c92b26911</id>
<content type='text'>
Pull perf tools updates from Arnaldo Carvalho de Melo:

 - Extended 'perf annotate' with DWARF type information
   (--code-with-type) integration in the TUI, including a 'T'
   hotkey to toggle it

 - Enhanced 'perf bench mem' with new mmap() workloads and control
   over page/chunk sizes

 - Fix 'perf stat' error handling to correctly display unsupported
   events

 - Improved support for Clang cross-compilation

 - Refactored LLVM and Capstone disasm for modularity

 - Introduced the :X modifier to exclude an event from automatic
   regrouping

 - Adjusted KVM sampling defaults to use the "cycles" event to prevent
   failures

 - Added comprehensive support for decoding PowerPC Dispatch Trace Log
   (DTL)

 - Updated Arm SPE tracing logic for better analysis of memory and snoop
   details

 - Synchronized Intel PMU events and metrics with TMA 5.1 across
   multiple processor generations

 - Converted dependencies like libperl and libtracefs to be opt-in

 - Handle more Rust symbols in kallsyms ('N', debugging)

 - Improve the python binding to allow for python based tools to use
   more of the libraries, add a 'ilist' utility to test those new
   bindings

 - Various 'perf test' fixes

 - Kan Liang no longer a perf tools reviewer

* tag 'perf-tools-for-v6.18-1-2025-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (192 commits)
  perf tools: Fix arm64 libjvmti build by generating unistd_64.h
  perf tests: Don't retest sections in "Object code reading"
  perf docs: Document building with Clang
  perf build: Support build with clang
  perf test coresight: Dismiss clang warning for unroll loop thread
  perf test coresight: Dismiss clang warning for thread loop
  perf test coresight: Dismiss clang warning for memcpy thread
  perf build: Disable thread safety analysis for perl header
  perf build: Correct CROSS_ARCH for clang
  perf python: split Clang options when invoking Popen
  tools build: Align warning options with perf
  perf disasm: Remove unused evsel from 'struct annotate_args'
  perf srcline: Fallback between addr2line implementations
  perf disasm: Make ins__scnprintf() and ins__is_nop() static
  perf dso: Clean up read_symbol() error handling
  perf dso: Support BPF programs in dso__read_symbol()
  perf dso: Move read_symbol() from llvm/capstone to dso
  perf llvm: Reduce LLVM initialization
  perf check: Add libLLVM feature
  perf parse-events: Fix parsing of &gt;30kb event strings
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf tools updates from Arnaldo Carvalho de Melo:

 - Extended 'perf annotate' with DWARF type information
   (--code-with-type) integration in the TUI, including a 'T'
   hotkey to toggle it

 - Enhanced 'perf bench mem' with new mmap() workloads and control
   over page/chunk sizes

 - Fix 'perf stat' error handling to correctly display unsupported
   events

 - Improved support for Clang cross-compilation

 - Refactored LLVM and Capstone disasm for modularity

 - Introduced the :X modifier to exclude an event from automatic
   regrouping

 - Adjusted KVM sampling defaults to use the "cycles" event to prevent
   failures

 - Added comprehensive support for decoding PowerPC Dispatch Trace Log
   (DTL)

 - Updated Arm SPE tracing logic for better analysis of memory and snoop
   details

 - Synchronized Intel PMU events and metrics with TMA 5.1 across
   multiple processor generations

 - Converted dependencies like libperl and libtracefs to be opt-in

 - Handle more Rust symbols in kallsyms ('N', debugging)

 - Improve the python binding to allow for python based tools to use
   more of the libraries, add a 'ilist' utility to test those new
   bindings

 - Various 'perf test' fixes

 - Kan Liang no longer a perf tools reviewer

* tag 'perf-tools-for-v6.18-1-2025-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (192 commits)
  perf tools: Fix arm64 libjvmti build by generating unistd_64.h
  perf tests: Don't retest sections in "Object code reading"
  perf docs: Document building with Clang
  perf build: Support build with clang
  perf test coresight: Dismiss clang warning for unroll loop thread
  perf test coresight: Dismiss clang warning for thread loop
  perf test coresight: Dismiss clang warning for memcpy thread
  perf build: Disable thread safety analysis for perl header
  perf build: Correct CROSS_ARCH for clang
  perf python: split Clang options when invoking Popen
  tools build: Align warning options with perf
  perf disasm: Remove unused evsel from 'struct annotate_args'
  perf srcline: Fallback between addr2line implementations
  perf disasm: Make ins__scnprintf() and ins__is_nop() static
  perf dso: Clean up read_symbol() error handling
  perf dso: Support BPF programs in dso__read_symbol()
  perf dso: Move read_symbol() from llvm/capstone to dso
  perf llvm: Reduce LLVM initialization
  perf check: Add libLLVM feature
  perf parse-events: Fix parsing of &gt;30kb event strings
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Fix arm64 libjvmti build by generating unistd_64.h</title>
<updated>2025-10-06T20:16:52+00:00</updated>
<author>
<name>Vincent Minet</name>
<email>v.minet@criteo.com</email>
</author>
<published>2025-09-22T05:37:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f3b601f900902ab80902c44f820a8985384ac021'/>
<id>f3b601f900902ab80902c44f820a8985384ac021</id>
<content type='text'>
Since commit 22f72088ffe6 ("tools headers: Update the syscall table with
the kernel sources") the arm64 syscall header is generated at build
time. Later, commit bfb713ea53c7 ("perf tools: Fix arm64 build by
generating unistd_64.h") added a dependency to libperf to guarantee that
this header was created before building libperf or perf itself.

However, libjvmti also requires this header but does not depend on
libperf, leading to build failures such as:

  In file included from /usr/include/sys/syscall.h:24,
                   from /usr/include/syscall.h:1,
                   from jvmti/jvmti_agent.c:36:
  tools/arch/arm64/include/uapi/asm/unistd.h:2:10: fatal error: asm/unistd_64.h: No such file or directory
      2 | #include &lt;asm/unistd_64.h&gt;

Fix this by ensuring that libperf is built before libjvmti, so that
unistd_64.h is always available.

Fixes: 22f72088ffe69a37 ("tools headers: Update the syscall table with the kernel sources")
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Vincent Minet &lt;v.minet@criteo.com&gt;
Link: https://lore.kernel.org/r/20250922053702.2688374-1-v.minet@criteo.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>
Since commit 22f72088ffe6 ("tools headers: Update the syscall table with
the kernel sources") the arm64 syscall header is generated at build
time. Later, commit bfb713ea53c7 ("perf tools: Fix arm64 build by
generating unistd_64.h") added a dependency to libperf to guarantee that
this header was created before building libperf or perf itself.

However, libjvmti also requires this header but does not depend on
libperf, leading to build failures such as:

  In file included from /usr/include/sys/syscall.h:24,
                   from /usr/include/syscall.h:1,
                   from jvmti/jvmti_agent.c:36:
  tools/arch/arm64/include/uapi/asm/unistd.h:2:10: fatal error: asm/unistd_64.h: No such file or directory
      2 | #include &lt;asm/unistd_64.h&gt;

Fix this by ensuring that libperf is built before libjvmti, so that
unistd_64.h is always available.

Fixes: 22f72088ffe69a37 ("tools headers: Update the syscall table with the kernel sources")
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Vincent Minet &lt;v.minet@criteo.com&gt;
Link: https://lore.kernel.org/r/20250922053702.2688374-1-v.minet@criteo.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tests: Don't retest sections in "Object code reading"</title>
<updated>2025-10-06T19:59:11+00:00</updated>
<author>
<name>James Clark</name>
<email>james.clark@linaro.org</email>
</author>
<published>2025-10-06T13:11:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5205c3d002662093150fdcfd2a236ab897ffb5a5'/>
<id>5205c3d002662093150fdcfd2a236ab897ffb5a5</id>
<content type='text'>
We already only test each kcore map once, but on slow systems
(particularly with network filesystems) even the non-kcore maps are
slow.

The test can test the same objdump output over and over which only wastes
time. Generalize the skipping mechanism to track all DSOs and addresses
so that each section is only tested once.

On a fully loaded ARM Juno (simulating a parallel 'perf test' run) with
a network filesystem, the original runtime is:

  real  1m51.126s
  user  0m19.445s
  sys   1m15.431s

And the new runtime is:

  real  0m48.873s
  user  0m8.031s
  sys   0m32.353s

Committer testing:

  # perf test "code read"
   22: Object code reading          : Ok
  #

Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Leo Yan &lt;leo.yan@arm.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
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>
We already only test each kcore map once, but on slow systems
(particularly with network filesystems) even the non-kcore maps are
slow.

The test can test the same objdump output over and over which only wastes
time. Generalize the skipping mechanism to track all DSOs and addresses
so that each section is only tested once.

On a fully loaded ARM Juno (simulating a parallel 'perf test' run) with
a network filesystem, the original runtime is:

  real  1m51.126s
  user  0m19.445s
  sys   1m15.431s

And the new runtime is:

  real  0m48.873s
  user  0m8.031s
  sys   0m32.353s

Committer testing:

  # perf test "code read"
   22: Object code reading          : Ok
  #

Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Signed-off-by: James Clark &lt;james.clark@linaro.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Leo Yan &lt;leo.yan@arm.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf docs: Document building with Clang</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0a75ba3e842c73f60767333b349cf456dca74e1f'/>
<id>0a75ba3e842c73f60767333b349cf456dca74e1f</id>
<content type='text'>
Add example commands for building perf with Clang.

Since recent Android NDK releases use Clang as the default compiler, a
separate Android specific document is no longer needed; point to the
general build documentation instead.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-9-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
Add example commands for building perf with Clang.

Since recent Android NDK releases use Clang as the default compiler, a
separate Android specific document is no longer needed; point to the
general build documentation instead.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-9-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf build: Support build with clang</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4772e66cb45e0dd2c3c9ac649532756c523afd1e'/>
<id>4772e66cb45e0dd2c3c9ac649532756c523afd1e</id>
<content type='text'>
Add support for building perf with clang. For cross compilation, the
Makefile dynamically selects target flag for corresponding arch.

This patch has been verified on x86_64 machine with Ubuntu distro, it
can build successfully for native target, and for cross building Arm64
and s390.

Example: native build on x86_64 / Ubuntu machine:

  $ HOSTCC=clang CC=clang CXX=clang++ make -C tools/perf

Example: cross building s390 target on x86_64 / Ubuntu machine:

  # Install x390x cross toolchain and headers
  $ sudo apt-get install gcc-s390x-linux-gnu g++-s390x-linux-gnu \
         libc6-dev-s390x-cross linux-libc-dev-s390x-cross

  # Build with clang
  $ HOSTCC=clang CC=clang CXX=clang++ \
    ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- \
    make -C tools/perf NO_LIBELF=1 NO_LIBTRACEEVENT=1 NO_LIBPYTHON=1

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-8-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
Add support for building perf with clang. For cross compilation, the
Makefile dynamically selects target flag for corresponding arch.

This patch has been verified on x86_64 machine with Ubuntu distro, it
can build successfully for native target, and for cross building Arm64
and s390.

Example: native build on x86_64 / Ubuntu machine:

  $ HOSTCC=clang CC=clang CXX=clang++ make -C tools/perf

Example: cross building s390 target on x86_64 / Ubuntu machine:

  # Install x390x cross toolchain and headers
  $ sudo apt-get install gcc-s390x-linux-gnu g++-s390x-linux-gnu \
         libc6-dev-s390x-cross linux-libc-dev-s390x-cross

  # Build with clang
  $ HOSTCC=clang CC=clang CXX=clang++ \
    ARCH=s390 CROSS_COMPILE=s390x-linux-gnu- \
    make -C tools/perf NO_LIBELF=1 NO_LIBTRACEEVENT=1 NO_LIBPYTHON=1

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-8-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test coresight: Dismiss clang warning for unroll loop thread</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9ec46fc9380329de9dfd70de521e9da97cb4dfa8'/>
<id>9ec46fc9380329de9dfd70de521e9da97cb4dfa8</id>
<content type='text'>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  unroll_loop_thread.c:35:25: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     35 |                         : /* in */ [in] "r" (in)
        |                                              ^
  unroll_loop_thread.c:39:1: warning: non-void function does not return a value [-Wreturn-type]
     39 | }
        | ^

Use the modifier "w" for 32-bit register access and return NULL at the
end of thread function.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-7-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  unroll_loop_thread.c:35:25: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     35 |                         : /* in */ [in] "r" (in)
        |                                              ^
  unroll_loop_thread.c:39:1: warning: non-void function does not return a value [-Wreturn-type]
     39 | }
        | ^

Use the modifier "w" for 32-bit register access and return NULL at the
end of thread function.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-7-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test coresight: Dismiss clang warning for thread loop</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=244a1ac76a671f100321ac2563b002b0354cbf42'/>
<id>244a1ac76a671f100321ac2563b002b0354cbf42</id>
<content type='text'>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:37:8: note: use constraint modifier "w"
     37 |                 "add %[i], %[i], #1\n"
        |                      ^~~~
        |                      %w[i]
  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:37:14: note: use constraint modifier "w"
     37 |                 "add %[i], %[i], #1\n"
        |                            ^~~~
        |                            %w[i]
  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:38:8: note: use constraint modifier "w"
     38 |                 "cmp %[i], %[len]\n"
        |                      ^~~~
        |                      %w[i]
  thread_loop.c:41:38: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                                    ^
  thread_loop.c:38:14: note: use constraint modifier "w"
     38 |                 "cmp %[i], %[len]\n"
        |                            ^~~~~~
        |                            %w[len]

Use the modifier "w" for 32-bit register access.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-6-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:37:8: note: use constraint modifier "w"
     37 |                 "add %[i], %[i], #1\n"
        |                      ^~~~
        |                      %w[i]
  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:37:14: note: use constraint modifier "w"
     37 |                 "add %[i], %[i], #1\n"
        |                            ^~~~
        |                            %w[i]
  thread_loop.c:41:23: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                     ^
  thread_loop.c:38:8: note: use constraint modifier "w"
     38 |                 "cmp %[i], %[len]\n"
        |                      ^~~~
        |                      %w[i]
  thread_loop.c:41:38: warning: value size does not match register size specified by the constraint and modifier [-Wasm-operand-widths]
     41 |                 : /* in */ [i] "r" (i), [len] "r" (len)
        |                                                    ^
  thread_loop.c:38:14: note: use constraint modifier "w"
     38 |                 "cmp %[i], %[len]\n"
        |                            ^~~~~~
        |                            %w[len]

Use the modifier "w" for 32-bit register access.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-6-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test coresight: Dismiss clang warning for memcpy thread</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=50b7e7082a3dde5bdba14a4e40a2e2279fd08a7b'/>
<id>50b7e7082a3dde5bdba14a4e40a2e2279fd08a7b</id>
<content type='text'>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  memcpy_thread.c:30:1: warning: non-void function does not return a value in all control paths [-Wreturn-type]
     30 | }
        | ^

Dismiss the warning with returning NULL from the thread function.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-5-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
clang-18.1.3 on Ubuntu 24.04.2 reports warning:

  memcpy_thread.c:30:1: warning: non-void function does not return a value in all control paths [-Wreturn-type]
     30 | }
        | ^

Dismiss the warning with returning NULL from the thread function.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-5-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf build: Disable thread safety analysis for perl header</title>
<updated>2025-10-06T19:49:25+00:00</updated>
<author>
<name>Leo Yan</name>
<email>leo.yan@arm.com</email>
</author>
<published>2025-10-06T16:21:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e7e86d7697c6ed1dbbde18d7185c35b6967945ed'/>
<id>e7e86d7697c6ed1dbbde18d7185c35b6967945ed</id>
<content type='text'>
When build with perl5, it reports error:

    In file included from /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7933:
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/inline.h:298:5: error:
          mutex 'PL_env_mutex.lock' is not held on every path through
          here [-Werror,-Wthread-safety-analysis]
      298 |     ENV_UNLOCK;
          |     ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7091:31: note:
          expanded from macro 'ENV_UNLOCK'
     7091 | #  define ENV_UNLOCK          PERL_REENTRANT_UNLOCK("env"...
          |                               ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:6465:7: note:
          expanded from macro 'PERL_REENTRANT_UNLOCK'
     6465 |     } STMT_END
          |       ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:865:28: note:
          expanded from macro 'STMT_END'
      865 | #   define STMT_END     while (0)
          |                                ^

The error is caused by perl header but not perf code, disable thread
safety analysis if including the header.

Though GCC does not support the thread safety analysis option, this
negative warning flag is silently ignored by it.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-4-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.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>
When build with perl5, it reports error:

    In file included from /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7933:
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/inline.h:298:5: error:
          mutex 'PL_env_mutex.lock' is not held on every path through
          here [-Werror,-Wthread-safety-analysis]
      298 |     ENV_UNLOCK;
          |     ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:7091:31: note:
          expanded from macro 'ENV_UNLOCK'
     7091 | #  define ENV_UNLOCK          PERL_REENTRANT_UNLOCK("env"...
          |                               ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:6465:7: note:
          expanded from macro 'PERL_REENTRANT_UNLOCK'
     6465 |     } STMT_END
          |       ^
    /usr/lib/perl5/5.42.0/x86_64-linux-thread-multi/CORE/perl.h:865:28: note:
          expanded from macro 'STMT_END'
      865 | #   define STMT_END     while (0)
          |                                ^

The error is caused by perl header but not perf code, disable thread
safety analysis if including the header.

Though GCC does not support the thread safety analysis option, this
negative warning flag is silently ignored by it.

Signed-off-by: Leo Yan &lt;leo.yan@arm.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Link: https://lore.kernel.org/r/20251006-perf_build_android_ndk-v3-4-4305590795b2@arm.com
Cc: Palmer Dabbelt &lt;palmer@dabbelt.com&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Cc: Nick Desaulniers &lt;nick.desaulniers+lkml@gmail.com&gt;
Cc: Justin Stitt &lt;justinstitt@google.com&gt;
Cc: Bill Wendling &lt;morbo@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: James Clark &lt;james.clark@linaro.org&gt;
Cc: linux-riscv@lists.infradead.org
Cc: llvm@lists.linux.dev
Cc: Paul Walmsley &lt;paul.walmsley@sifive.com&gt;
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
