3a36281a17
- 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
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v5.12-2020-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
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
...
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.