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perf_session__fprintf() prints only the host.
This has been changed to print details of host and all guests, by
traversing through the RB-Tree.
These are visible when using high verbosity (-vvvv) in KVM environments,
during perf report dumps.
Testing:
- Test 1: Record the local machine and guest VM using 'perf kvm record' and
generate the report using 'perf kvm report -vvvv -D'. The dump should show
the threads and other details related to local and guest machine.
- 1 Ubuntu VM running on Fedora host
- VM is running a noisy program =>
$ dd if=/dev/urandom of=/dev/null
- On host run =>
$ sudo ./perf kvm --guestvmlinux=/tmp/shared/guest_vmlinux \
--guestkallsyms=/tmp/shared/guest_kallsyms \
--guestmodules=/tmp/shared/guest_modules \
record -a -g -o perf.data.guest
and exit after a few seconds.
[ perf record: Woken up 9 times to write data ]
[ perf record: Captured and wrote 3.150 MB perf.data.guest \
(29311 samples) ]
- Generate dump =>
$ sudo ./perf kvm --guestkallsyms /tmp/shared/guest_kallsyms \
report -vvvv -D -i perf.data.guest > output.txt
- Check for threads associated with guest machine.
$ grep "Thread 0" output.txt
Thread 0 swapper
Thread 0 [guest/0]
PASS
- Test 2: Record the local machine and guest VM using 'perf kvm record' and
generate the report using 'perf kvm report'. The functions running on
guest VM should be seen in the report.
- Same setup as Test 1 but the test looks at the performance profile,
to check if the function names are visible.
- Peek into profile using =>
$ sudo ./perf kvm --guestkallsyms /tmp/shared/guest_kallsyms \
report -i perf.data.guest
- Samples: 29K of event 'cycles', Event count (approx.): 28711693142
Children Self Command Shared Object Symbol
35.69% 35.69% :5820 [guest.kernel.kallsyms] [g] chacha_permute
11.56% 11.56% :5820 [guest.kernel.kallsyms] [g] entry_SYSRETQ_unsXXX
11.12% 11.12% :5820 [guest.kernel.kallsyms] [g] syscall_return_viXXX
7.36% 7.36% :5820 [guest.kernel.kallsyms] [g] entry_SYSCALL_64_XXX
6.07% 6.07% :5820 [guest.kernel.kallsyms] [g] chacha_block_generic
5.40% 5.40% :5820 [guest.kernel.kallsyms] [g] _copy_to_iter
....
PASS
- Test 3: Record the local and 2 guest VMs using 'perf kvm record' and
generate the report using 'perf kvm report -vvvv -D'. The dump should show
the threads and other details related to local and guest machines.
- 1 Ubuntu and 1 Alpine VMs running on Fedora host.
- Find PIDs of qemu instances and use them during record and report
$ pgrep qemu
5816
25098
- Record the activity =>
$ sudo ./perf kvm record -p 5816,25098 -a -g -o perf.data.guests
Warning:
PID/TID switch overriding SYSTEM
[ perf record: Woken up 325927 times to write data ]
[ perf record: Captured and wrote 3.692 MB perf.data.guests \
(57389 samples) ]
- Generate dump =>
$ sudo ./perf kvm report -vvvv -D -i perf.data.guests > output.txt
- Check if the threads related to the local machine and guest VMs
are present =>
$ grep "Thread 0" output.txt
Thread 0 swapper
Thread 0 [guest/0]
NOTE: Threads from Ubuntu and Alpine VMs are bundled together and
appear as one guest machine.
Looking into output.txt =>
Threads: 6
Thread 0 [guest/0]
Thread 5816 :5816
Thread 25098 :25098
Thread 5819 :5819
Thread 5820 :5820
Thread 25103 :25103
To conclude, information is collected for both VMs and not listed
as two different guest machines.
PASS
- Test 4: Check if any guest-related information is printed in
perf annotate. This test is included because the command calls
perf_session__fprintf() in its code path when using -vvvv option.
This could be explained by inability / lack of options for 'perf annotate'
to look into guest VM from host machine, due to no option to specify the
guest's kallsyms or modules. A similar explanation for 'perf mem' could
be used, as perf_session__fprintf() is also present in its code path.
- Run annotate =>
$ sudo ./perf annotate -i perf.data.guest -vvvv > output.txt
- Check for threads from local machine or guest VM =>
$ grep "Thread 0" output.txt
Thread 0 swapper
Threads from local machine are found while threads from guest VM
are not found. It is possibly because of a lack of a guest kallsyms
option for DSO matching in perf annotate.
PASS
- Test 5: Run kvm test available on perf path
- $ sudo ./perf test kvm
89: perf kvm tests : Ok
PASS
Signed-off-by: Hrishikesh Suresh <hrishikesh123s@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Blake Jones <blakejones@google.com>
Cc: Chun-Tse Shao <ctshao@google.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
[ Declare 'nd' in the 'for' line and and 'pos' inside the loop body, to make it more compact ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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| ipc | ||
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| lib | ||
| LICENSES | ||
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| tools | ||
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| .clang-format | ||
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| .get_maintainer.ignore | ||
| .gitattributes | ||
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| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ The Linux kernel is the core of any Linux operating system. It manages hardware, system resources, and provides the fundamental services for all other software. Quick Start ----------- * Report a bug: See Documentation/admin-guide/reporting-issues.rst * Get the latest kernel: https://kernel.org * Build the kernel: See Documentation/admin-guide/quickly-build-trimmed-linux.rst * Join the community: https://lore.kernel.org/ Essential Documentation ----------------------- All users should be familiar with: * Building requirements: Documentation/process/changes.rst * Code of Conduct: Documentation/process/code-of-conduct.rst * License: See COPYING Documentation can be built with make htmldocs or viewed online at: https://www.kernel.org/doc/html/latest/ Who Are You? ============ Find your role below: * New Kernel Developer - Getting started with kernel development * Academic Researcher - Studying kernel internals and architecture * Security Expert - Hardening and vulnerability analysis * Backport/Maintenance Engineer - Maintaining stable kernels * System Administrator - Configuring and troubleshooting * Maintainer - Leading subsystems and reviewing patches * Hardware Vendor - Writing drivers for new hardware * Distribution Maintainer - Packaging kernels for distros For Specific Users ================== New Kernel Developer -------------------- Welcome! Start your kernel development journey here: * Getting Started: Documentation/process/development-process.rst * Your First Patch: Documentation/process/submitting-patches.rst * Coding Style: Documentation/process/coding-style.rst * Build System: Documentation/kbuild/index.rst * Development Tools: Documentation/dev-tools/index.rst * Kernel Hacking Guide: Documentation/kernel-hacking/hacking.rst * Core APIs: Documentation/core-api/index.rst Academic Researcher ------------------- Explore the kernel's architecture and internals: * Researcher Guidelines: Documentation/process/researcher-guidelines.rst * Memory Management: Documentation/mm/index.rst * Scheduler: Documentation/scheduler/index.rst * Networking Stack: Documentation/networking/index.rst * Filesystems: Documentation/filesystems/index.rst * RCU (Read-Copy Update): Documentation/RCU/index.rst * Locking Primitives: Documentation/locking/index.rst * Power Management: Documentation/power/index.rst Security Expert --------------- Security documentation and hardening guides: * Security Documentation: Documentation/security/index.rst * LSM Development: Documentation/security/lsm-development.rst * Self Protection: Documentation/security/self-protection.rst * Reporting Vulnerabilities: Documentation/process/security-bugs.rst * CVE Procedures: Documentation/process/cve.rst * Embargoed Hardware Issues: Documentation/process/embargoed-hardware-issues.rst * Security Features: Documentation/userspace-api/seccomp_filter.rst Backport/Maintenance Engineer ----------------------------- Maintain and stabilize kernel versions: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * Backporting Guide: Documentation/process/backporting.rst * Applying Patches: Documentation/process/applying-patches.rst * Subsystem Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git for Maintainers: Documentation/maintainer/configure-git.rst System Administrator -------------------- Configure, tune, and troubleshoot Linux systems: * Admin Guide: Documentation/admin-guide/index.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Sysctl Tuning: Documentation/admin-guide/sysctl/index.rst * Tracing/Debugging: Documentation/trace/index.rst * Performance Security: Documentation/admin-guide/perf-security.rst * Hardware Monitoring: Documentation/hwmon/index.rst Maintainer ---------- Lead kernel subsystems and manage contributions: * Maintainer Handbook: Documentation/maintainer/index.rst * Pull Requests: Documentation/maintainer/pull-requests.rst * Managing Patches: Documentation/maintainer/modifying-patches.rst * Rebasing and Merging: Documentation/maintainer/rebasing-and-merging.rst * Development Process: Documentation/process/maintainer-handbooks.rst * Maintainer Entry Profile: Documentation/maintainer/maintainer-entry-profile.rst * Git Configuration: Documentation/maintainer/configure-git.rst Hardware Vendor --------------- Write drivers and support new hardware: * Driver API Guide: Documentation/driver-api/index.rst * Driver Model: Documentation/driver-api/driver-model/driver.rst * Device Drivers: Documentation/driver-api/infrastructure.rst * Bus Types: Documentation/driver-api/driver-model/bus.rst * Device Tree Bindings: Documentation/devicetree/bindings/ * Power Management: Documentation/driver-api/pm/index.rst * DMA API: Documentation/core-api/dma-api.rst Distribution Maintainer ----------------------- Package and distribute the kernel: * Stable Kernel Rules: Documentation/process/stable-kernel-rules.rst * ABI Documentation: Documentation/ABI/README * Kernel Configuration: Documentation/kbuild/kconfig.rst * Module Signing: Documentation/admin-guide/module-signing.rst * Kernel Parameters: Documentation/admin-guide/kernel-parameters.rst * Tainted Kernels: Documentation/admin-guide/tainted-kernels.rst Communication and Support ========================= * Mailing Lists: https://lore.kernel.org/ * IRC: #kernelnewbies on irc.oftc.net * Bugzilla: https://bugzilla.kernel.org/ * MAINTAINERS file: Lists subsystem maintainers and mailing lists * Email Clients: Documentation/process/email-clients.rst