Revision f085df1be60abf670315c11036261cfaec16b2eb authored by Linus Torvalds on 07 May 2023, 18:32:18 UTC, committed by Linus Torvalds on 07 May 2023, 18:32:18 UTC
Pull perf tool updates from Arnaldo Carvalho de Melo: "Third version of perf tool updates, with the build problems with with using a 'vmlinux.h' generated from the main build fixed, and the bpf skeleton build disabled by default. Build: - Require libtraceevent to build, one can disable it using NO_LIBTRACEEVENT=1. It is required for tools like 'perf sched', 'perf kvm', 'perf trace', etc. libtraceevent is available in most distros so installing 'libtraceevent-devel' should be a one-time event to continue building perf as usual. Using NO_LIBTRACEEVENT=1 produces tooling that is functional and sufficient for lots of users not interested in those libtraceevent dependent features. - Allow Python support in 'perf script' when libtraceevent isn't linked, as not all features requires it, for instance Intel PT does not use tracepoints. - Error if the python interpreter needed for jevents to work isn't available and NO_JEVENTS=1 isn't set, preventing a build without support for JSON vendor events, which is a rare but possible condition. The two check error messages: $(error ERROR: No python interpreter needed for jevents generation. Install python or build with NO_JEVENTS=1.) $(error ERROR: Python interpreter needed for jevents generation too old (older than 3.6). Install a newer python or build with NO_JEVENTS=1.) - Make libbpf 1.0 the minimum required when building with out of tree, distro provided libbpf. - Use libsdtc++'s and LLVM's libcxx's __cxa_demangle, a portable C++ demangler, add 'perf test' entry for it. - Make binutils libraries opt in, as distros disable building with it due to licensing, they were used for C++ demangling, for instance. - Switch libpfm4 to opt-out rather than opt-in, if libpfm-devel (or equivalent) isn't installed, we'll just have a build warning: Makefile.config:1144: libpfm4 not found, disables libpfm4 support. Please install libpfm4-dev - Add a feature test for scandirat(), that is not implemented so far in musl and uclibc, disabling features that need it, such as scanning for tracepoints in /sys/kernel/tracing/events. perf BPF filters: - New feature where BPF can be used to filter samples, for instance: $ sudo ./perf record -e cycles --filter 'period > 1000' true $ sudo ./perf script perf-exec 2273949 546850.708501: 5029 cycles: ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms]) perf-exec 2273949 546850.708508: 32409 cycles: ffffffff826f9e25 finish_wait+0x5 ([kernel.kallsyms]) perf-exec 2273949 546850.708526: 143369 cycles: ffffffff82b4cdbf xas_start+0x5f ([kernel.kallsyms]) perf-exec 2273949 546850.708600: 372650 cycles: ffffffff8286b8f7 __pagevec_lru_add+0x117 ([kernel.kallsyms]) perf-exec 2273949 546850.708791: 482953 cycles: ffffffff829190de __mod_memcg_lruvec_state+0x4e ([kernel.kallsyms]) true 2273949 546850.709036: 501985 cycles: ffffffff828add7c tlb_gather_mmu+0x4c ([kernel.kallsyms]) true 2273949 546850.709292: 503065 cycles: 7f2446d97c03 _dl_map_object_deps+0x973 (/usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) - In addition to 'period' (PERF_SAMPLE_PERIOD), the other PERF_SAMPLE_ can be used for filtering, and also some other sample accessible values, from tools/perf/Documentation/perf-record.txt: Essentially the BPF filter expression is: <term> <operator> <value> (("," | "||") <term> <operator> <value>)* The <term> can be one of: ip, id, tid, pid, cpu, time, addr, period, txn, weight, phys_addr, code_pgsz, data_pgsz, weight1, weight2, weight3, ins_lat, retire_lat, p_stage_cyc, mem_op, mem_lvl, mem_snoop, mem_remote, mem_lock, mem_dtlb, mem_blk, mem_hops The <operator> can be one of: ==, !=, >, >=, <, <=, & The <value> can be one of: <number> (for any term) na, load, store, pfetch, exec (for mem_op) l1, l2, l3, l4, cxl, io, any_cache, lfb, ram, pmem (for mem_lvl) na, none, hit, miss, hitm, fwd, peer (for mem_snoop) remote (for mem_remote) na, locked (for mem_locked) na, l1_hit, l1_miss, l2_hit, l2_miss, any_hit, any_miss, walk, fault (for mem_dtlb) na, by_data, by_addr (for mem_blk) hops0, hops1, hops2, hops3 (for mem_hops) perf lock contention: - Show lock type with address. - Track and show mmap_lock, siglock and per-cpu rq_lock with address. This is done for mmap_lock by following the current->mm pointer: $ sudo ./perf lock con -abl -- sleep 10 contended total wait max wait avg wait address symbol ... 16344 312.30 ms 2.22 ms 19.11 us ffff8cc702595640 17686 310.08 ms 1.49 ms 17.53 us ffff8cc7025952c0 3 84.14 ms 45.79 ms 28.05 ms ffff8cc78114c478 mmap_lock 3557 76.80 ms 68.75 us 21.59 us ffff8cc77ca3af58 1 68.27 ms 68.27 ms 68.27 ms ffff8cda745dfd70 9 54.53 ms 7.96 ms 6.06 ms ffff8cc7642a48b8 mmap_lock 14629 44.01 ms 60.00 us 3.01 us ffff8cc7625f9ca0 3481 42.63 ms 140.71 us 12.24 us ffffffff937906ac vmap_area_lock 16194 38.73 ms 42.15 us 2.39 us ffff8cd397cbc560 11 38.44 ms 10.39 ms 3.49 ms ffff8ccd6d12fbb8 mmap_lock 1 5.43 ms 5.43 ms 5.43 ms ffff8cd70018f0d8 1674 5.38 ms 422.93 us 3.21 us ffffffff92e06080 tasklist_lock 581 4.51 ms 130.68 us 7.75 us ffff8cc9b1259058 5 3.52 ms 1.27 ms 703.23 us ffff8cc754510070 112 3.47 ms 56.47 us 31.02 us ffff8ccee38b3120 381 3.31 ms 73.44 us 8.69 us ffffffff93790690 purge_vmap_area_lock 255 3.19 ms 36.35 us 12.49 us ffff8d053ce30c80 - Update default map size to 16384. - Allocate single letter option -M for --map-nr-entries, as it is proving being frequently used. - Fix struct rq lock access for older kernels with BPF's CO-RE (Compile once, run everywhere). - Fix problems found with MSAn. perf report/top: - Add inline information when using --call-graph=fp or lbr, as was already done to the --call-graph=dwarf callchain mode. - Improve the 'srcfile' sort key performance by really using an optimization introduced in 6.2 for the 'srcline' sort key that avoids calling addr2line for comparision with each sample. perf sched: - Make 'perf sched latency/map/replay' to use "sched:sched_waking" instead of "sched:sched_waking", consistent with 'perf record' since d566a9c2d482 ("perf sched: Prefer sched_waking event when it exists"). perf ftrace: - Make system wide the default target for latency subcommand, run the following command then generate some network traffic and press control+C: # perf ftrace latency -T __kfree_skb ^C DURATION | COUNT | GRAPH | 0 - 1 us | 27 | ############# | 1 - 2 us | 22 | ########### | 2 - 4 us | 8 | #### | 4 - 8 us | 5 | ## | 8 - 16 us | 24 | ############ | 16 - 32 us | 2 | # | 32 - 64 us | 1 | | 64 - 128 us | 0 | | 128 - 256 us | 0 | | 256 - 512 us | 0 | | 512 - 1024 us | 0 | | 1 - 2 ms | 0 | | 2 - 4 ms | 0 | | 4 - 8 ms | 0 | | 8 - 16 ms | 0 | | 16 - 32 ms | 0 | | 32 - 64 ms | 0 | | 64 - 128 ms | 0 | | 128 - 256 ms | 0 | | 256 - 512 ms | 0 | | 512 - 1024 ms | 0 | | 1 - ... s | 0 | | # perf top: - Add --branch-history (LBR: Last Branch Record) option, just like already available for 'perf record'. - Fix segfault in thread__comm_len() where thread->comm was being used outside thread->comm_lock. perf annotate: - Allow configuring objdump and addr2line in ~/.perfconfig., so that you can use alternative binaries, such as llvm's. perf kvm: - Add TUI mode for 'perf kvm stat report'. Reference counting: - Add reference count checking infrastructure to check for use after free, done to the 'cpumap', 'namespaces', 'maps' and 'map' structs, more to come. To build with it use -DREFCNT_CHECKING=1 in the make command line to build tools/perf. Documented at: https://perf.wiki.kernel.org/index.php/Reference_Count_Checking - The above caught, for instance, fix, present in this series: - Fix maps use after put in 'perf test "Share thread maps"': 'maps' is copied from leader, but the leader is put on line 79 and then 'maps' is used to read the reference count below - so a use after put, with the put of maps happening within thread__put. Fixed by reversing the order of puts so that the leader is put last. - Also several fixes were made to places where reference counts were not being held. - Make this one of the tests in 'make -C tools/perf build-test' to regularly build test it and to make sure no direct access to the reference counted structs are made, doing that via accessors to check the validity of the struct pointer. ARM64: - Fix 'perf report' segfault when filtering coresight traces by sparse lists of CPUs. - Add support for 'simd' as a sort field for 'perf report', to show ARM's NEON SIMD's predicate flags: "partial" and "empty". arm64 vendor events: - Add N1 metrics. Intel vendor events: - Add graniterapids, grandridge and sierraforrest events. - Refresh events for: alderlake, aldernaken, broadwell, broadwellde, broadwellx, cascadelakx, haswell, haswellx, icelake, icelakex, jaketown, meteorlake, knightslanding, sandybridge, sapphirerapids, silvermont, skylake, tigerlake and westmereep-dp - Refresh metrics for alderlake-n, broadwell, broadwellde, broadwellx, haswell, haswellx, icelakex, ivybridge, ivytown and skylakex. perf stat: - Implement --topdown using JSON metrics. - Add TopdownL1 JSON metric as a default if present, but disable it for now for some Intel hybrid architectures, a series of patches addressing this is being reviewed and will be submitted for v6.5. - Use metrics for --smi-cost. - Update topdown documentation. Vendor events (JSON) infrastructure: - Add support for computing and printing metric threshold values. For instance, here is one found in thesapphirerapids json file: { "BriefDescription": "Percentage of cycles spent in System Management Interrupts.", "MetricExpr": "((msr@aperf@ - cycles) / msr@aperf@ if msr@smi@ > 0 else 0)", "MetricGroup": "smi", "MetricName": "smi_cycles", "MetricThreshold": "smi_cycles > 0.1", "ScaleUnit": "100%" }, - Test parsing metric thresholds with the fake PMU in 'perf test pmu-events'. - Support for printing metric thresholds in 'perf list'. - Add --metric-no-threshold option to 'perf stat'. - Add rand (reverse and) and has_pmem (optane memory) support to metrics. - Sort list of input files to avoid depending on the order from readdir() helping in obtaining reproducible builds. S/390: - Add common metrics: - CPI (cycles per instruction), prbstate (ratio of instructions executed in problem state compared to total number of instructions), l1mp (Level one instruction and data cache misses per 100 instructions). - Add cache metrics for z13, z14, z15 and z16. - Add metric for TLB and cache. ARM: - Add raw decoding for SPE (Statistical Profiling Extension) v1.3 MTE (Memory Tagging Extension) and MOPS (Memory Operations) load/store. Intel PT hardware tracing: - Add event type names UINTR (User interrupt delivered) and UIRET (Exiting from user interrupt routine), documented in table 32-50 "CFE Packet Type and Vector Fields Details" in the Intel Processor Trace chapter of The Intel SDM Volume 3 version 078. - Add support for new branch instructions ERETS and ERETU. - Fix CYC timestamps after standalone CBR ARM CoreSight hardware tracing: - Allow user to override timestamp and contextid settings. - Fix segfault in dso lookup. - Fix timeless decode mode detection. - Add separate decode paths for timeless and per-thread modes. auxtrace: - Fix address filter entire kernel size. Miscellaneous: - Fix use-after-free and unaligned bugs in the PLT handling routines. - Use zfree() to reduce chances of use after free. - Add missing 0x prefix for addresses printed in hexadecimal in 'perf probe'. - Suppress massive unsupported target platform errors in the unwind code. - Fix return incorrect build_id size in elf_read_build_id(). - Fix 'perf scripts intel-pt-events.py' IPC output for Python 2 . - Add missing new parameter in kfree_skb tracepoint to the python scripts using it. - Add 'perf bench syscall fork' benchmark. - Add support for printing PERF_MEM_LVLNUM_UNC (Uncached access) in 'perf mem'. - Fix wrong size expectation for perf test 'Setup struct perf_event_attr' caused by the patch adding perf_event_attr::config3. - Fix some spelling mistakes" * tag 'perf-tools-for-v6.4-3-2023-05-06' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (365 commits) Revert "perf build: Make BUILD_BPF_SKEL default, rename to NO_BPF_SKEL" Revert "perf build: Warn for BPF skeletons if endian mismatches" perf metrics: Fix SEGV with --for-each-cgroup perf bpf skels: Stop using vmlinux.h generated from BTF, use subset of used structs + CO-RE perf stat: Separate bperf from bpf_profiler perf test record+probe_libc_inet_pton: Fix call chain match on x86_64 perf test record+probe_libc_inet_pton: Fix call chain match on s390 perf tracepoint: Fix memory leak in is_valid_tracepoint() perf cs-etm: Add fix for coresight trace for any range of CPUs perf build: Fix unescaped # in perf build-test perf unwind: Suppress massive unsupported target platform errors perf script: Add new parameter in kfree_skb tracepoint to the python scripts using it perf script: Print raw ip instead of binary offset for callchain perf symbols: Fix return incorrect build_id size in elf_read_build_id() perf list: Modify the warning message about scandirat(3) perf list: Fix memory leaks in print_tracepoint_events() perf lock contention: Rework offset calculation with BPF CO-RE perf lock contention: Fix struct rq lock access perf stat: Disable TopdownL1 on hybrid perf stat: Avoid SEGV on counter->name ...
Kconfig
# SPDX-License-Identifier: GPL-2.0
#
# Configuration for initramfs
#
config INITRAMFS_SOURCE
string "Initramfs source file(s)"
default ""
help
This can be either a single cpio archive with a .cpio suffix or a
space-separated list of directories and files for building the
initramfs image. A cpio archive should contain a filesystem archive
to be used as an initramfs image. Directories should contain a
filesystem layout to be included in the initramfs image. Files
should contain entries according to the format described by the
"usr/gen_init_cpio" program in the kernel tree.
When multiple directories and files are specified then the
initramfs image will be the aggregate of all of them.
See <file:Documentation/driver-api/early-userspace/early_userspace_support.rst> for more details.
If you are not sure, leave it blank.
config INITRAMFS_FORCE
bool "Ignore the initramfs passed by the bootloader"
depends on CMDLINE_EXTEND || CMDLINE_FORCE
help
This option causes the kernel to ignore the initramfs image
(or initrd image) passed to it by the bootloader. This is
analogous to CMDLINE_FORCE, which is found on some architectures,
and is useful if you cannot or don't want to change the image
your bootloader passes to the kernel.
config INITRAMFS_ROOT_UID
int "User ID to map to 0 (user root)"
depends on INITRAMFS_SOURCE!=""
default "0"
help
If INITRAMFS_SOURCE points to a directory, files owned by this UID
(-1 = current user) will be owned by root in the resulting image.
If you are not sure, leave it set to "0".
config INITRAMFS_ROOT_GID
int "Group ID to map to 0 (group root)"
depends on INITRAMFS_SOURCE!=""
default "0"
help
If INITRAMFS_SOURCE points to a directory, files owned by this GID
(-1 = current group) will be owned by root in the resulting image.
If you are not sure, leave it set to "0".
config RD_GZIP
bool "Support initial ramdisk/ramfs compressed using gzip"
default y
select DECOMPRESS_GZIP
help
Support loading of a gzip encoded initial ramdisk or cpio buffer.
If unsure, say Y.
config RD_BZIP2
bool "Support initial ramdisk/ramfs compressed using bzip2"
default y
select DECOMPRESS_BZIP2
help
Support loading of a bzip2 encoded initial ramdisk or cpio buffer
If unsure, say N.
config RD_LZMA
bool "Support initial ramdisk/ramfs compressed using LZMA"
default y
select DECOMPRESS_LZMA
help
Support loading of a LZMA encoded initial ramdisk or cpio buffer
If unsure, say N.
config RD_XZ
bool "Support initial ramdisk/ramfs compressed using XZ"
default y
select DECOMPRESS_XZ
help
Support loading of a XZ encoded initial ramdisk or cpio buffer.
If unsure, say N.
config RD_LZO
bool "Support initial ramdisk/ramfs compressed using LZO"
default y
select DECOMPRESS_LZO
help
Support loading of a LZO encoded initial ramdisk or cpio buffer
If unsure, say N.
config RD_LZ4
bool "Support initial ramdisk/ramfs compressed using LZ4"
default y
select DECOMPRESS_LZ4
help
Support loading of a LZ4 encoded initial ramdisk or cpio buffer
If unsure, say N.
config RD_ZSTD
bool "Support initial ramdisk/ramfs compressed using ZSTD"
default y
select DECOMPRESS_ZSTD
help
Support loading of a ZSTD encoded initial ramdisk or cpio buffer.
If unsure, say N.
choice
prompt "Built-in initramfs compression mode"
depends on INITRAMFS_SOURCE != ""
help
This option allows you to decide by which algorithm the builtin
initramfs will be compressed. Several compression algorithms are
available, which differ in efficiency, compression and
decompression speed. Compression speed is only relevant
when building a kernel. Decompression speed is relevant at
each boot. Also the memory usage during decompression may become
relevant on memory constrained systems. This is usually based on the
dictionary size of the algorithm with algorithms like XZ and LZMA
featuring large dictionary sizes.
High compression options are mostly useful for users who are
low on RAM, since it reduces the memory consumption during
boot.
Keep in mind that your build system needs to provide the appropriate
compression tool to compress the generated initram cpio file for
embedding.
If in doubt, select 'None'
config INITRAMFS_COMPRESSION_GZIP
bool "Gzip"
depends on RD_GZIP
help
Use the old and well tested gzip compression algorithm. Gzip provides
a good balance between compression ratio and decompression speed and
has a reasonable compression speed. It is also more likely to be
supported by your build system as the gzip tool is present by default
on most distros.
config INITRAMFS_COMPRESSION_BZIP2
bool "Bzip2"
depends on RD_BZIP2
help
It's compression ratio and speed is intermediate. Decompression speed
is slowest among the choices. The initramfs size is about 10% smaller
with bzip2, in comparison to gzip. Bzip2 uses a large amount of
memory. For modern kernels you will need at least 8MB RAM or more for
booting.
If you choose this, keep in mind that you need to have the bzip2 tool
available to be able to compress the initram.
config INITRAMFS_COMPRESSION_LZMA
bool "LZMA"
depends on RD_LZMA
help
This algorithm's compression ratio is best but has a large dictionary
size which might cause issues in memory constrained systems.
Decompression speed is between the other choices. Compression is
slowest. The initramfs size is about 33% smaller with LZMA in
comparison to gzip.
If you choose this, keep in mind that you may need to install the xz
or lzma tools to be able to compress the initram.
config INITRAMFS_COMPRESSION_XZ
bool "XZ"
depends on RD_XZ
help
XZ uses the LZMA2 algorithm and has a large dictionary which may cause
problems on memory constrained systems. The initramfs size is about
30% smaller with XZ in comparison to gzip. Decompression speed is
better than that of bzip2 but worse than gzip and LZO. Compression is
slow.
If you choose this, keep in mind that you may need to install the xz
tool to be able to compress the initram.
config INITRAMFS_COMPRESSION_LZO
bool "LZO"
depends on RD_LZO
help
It's compression ratio is the second poorest amongst the choices. The
kernel size is about 10% bigger than gzip. Despite that, it's
decompression speed is the second fastest and it's compression speed
is quite fast too.
If you choose this, keep in mind that you may need to install the lzop
tool to be able to compress the initram.
config INITRAMFS_COMPRESSION_LZ4
bool "LZ4"
depends on RD_LZ4
help
It's compression ratio is the poorest amongst the choices. The kernel
size is about 15% bigger than gzip; however its decompression speed
is the fastest.
If you choose this, keep in mind that most distros don't provide lz4
by default which could cause a build failure.
config INITRAMFS_COMPRESSION_ZSTD
bool "ZSTD"
depends on RD_ZSTD
help
ZSTD is a compression algorithm targeting intermediate compression
with fast decompression speed. It will compress better than GZIP and
decompress around the same speed as LZO, but slower than LZ4.
If you choose this, keep in mind that you may need to install the zstd
tool to be able to compress the initram.
config INITRAMFS_COMPRESSION_NONE
bool "None"
help
Do not compress the built-in initramfs at all. This may sound wasteful
in space, but, you should be aware that the built-in initramfs will be
compressed at a later stage anyways along with the rest of the kernel,
on those architectures that support this. However, not compressing the
initramfs may lead to slightly higher memory consumption during a
short time at boot, while both the cpio image and the unpacked
filesystem image will be present in memory simultaneously
endchoice
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