user/sven/linux.git/tools/lib/api, branch v5.9.2

libperf: Avoid counting of nonfilterable fdarray fds

2020-07-21T12:53:22Z

Avoid counting of struct pollfd *entries objects with fdarray_flag__nonfilterable flag by fdarray__filter(). Nonfilterable objects are still processed if requested revents have been signaled for them. Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/b5ab0d2c-b742-0032-e8d3-c8e2eb423c42@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add flags to fdarray fds objects

2020-07-21T12:52:51Z

Store flags per struct pollfd *entries object in a bitmap of int size. Implement fdarray_flag__nonfilterable flag to skip object from counting by fdarray__filter(). Fixed fdarray test issue reported by kernel test robot. Reported-by: kernel test robot Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/6b7d43ff-0801-d5dd-4e90-fcd86b17c1c8@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

libperf: Avoid internal moving of fdarray fds

2020-07-21T11:49:30Z

Avoid moving of fds by fdarray__filter() so fds indices returned by fdarray__add() can be used for access and processing of objects at struct pollfd *entries. Signed-off-by: Alexey Budankov Acked-by: Jiri Olsa Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/676844f8-55d3-c628-23db-aa163a81519e@linux.intel.com Signed-off-by: Arnaldo Carvalho de Melo

libsymbols kallsyms: Parse using io api

2020-05-05T19:35:32Z

'perf record' will call kallsyms__parse 4 times during startup and process megabytes of data. This changes kallsyms__parse to use the io library rather than fgets to improve performance of the user code by over 8%. Before: Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 103.988 ms (+- 0.203 ms) After: Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 95.571 ms (+- 0.006 ms) For a workload like: $ perf record /bin/true Run under 'perf record -e cycles:u -g' the time goes from: Before 30.10% 1.67% perf perf [.] kallsyms__parse After 25.55% 20.04% perf perf [.] kallsyms__parse So a little under 5% of the start-up time is removed. A lot of what remains is on the kernel side, but caching kallsyms within perf would at least impact memory footprint. Committer notes: The internal/kallsyms-parse bench is run using: [root@five ~]# perf bench internals kallsyms-parse # Running 'internals/kallsyms-parse' benchmark: Average kallsyms__parse took: 80.381 ms (+- 0.115 ms) [root@five ~]# And this pre-existing test uses these routines to parse kallsyms and then compare with the info obtained from the matching ELF symtab: [root@five ~]# perf test vmlinux 1: vmlinux symtab matches kallsyms : Ok [root@five ~]# Also we can't remove hex2u64() in this patch as this breaks the build: /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `modules__parse': /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64' /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:607: undefined reference to `hex2u64' /usr/bin/ld: /tmp/build/perf/perf-in.o: in function `dso__load_perf_map': /home/acme/git/perf/tools/perf/util/symbol.c:1477: undefined reference to `hex2u64' /usr/bin/ld: /home/acme/git/perf/tools/perf/util/symbol.c:1483: undefined reference to `hex2u64' collect2: error: ld returned 1 exit status Leave it there, move it in the next patch. Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200501221315.54715-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

tools api: Add a lightweight buffered reading api

2020-04-30T13:48:28Z

The synthesize benchmark shows the majority of execution time going to fgets and sscanf, necessary to parse /proc/pid/maps. Add a new buffered reading library that will be used to replace these calls in a follow-up CL. Add tests for the library to perf test. Committer tests: $ perf test api 63: Test api io : Ok $ Signed-off-by: Ian Rogers Acked-by: Jiri Olsa Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Andrey Zhizhikin Cc: Jiri Olsa Cc: Kan Liang Cc: Kefeng Wang Cc: Mark Rutland Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephane Eranian Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200415054050.31645-3-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

tools api fs: Make xxx__mountpoint() more scalable

2020-04-16T15:19:12Z

The xxx_mountpoint() interface provided by fs.c finds mount points for common pseudo filesystems. The first time xxx_mountpoint() is invoked, it scans the mount table (/proc/mounts) looking for a match. If found, it is cached. The price to scan /proc/mounts is paid once if the mount is found. When the mount point is not found, subsequent calls to xxx_mountpoint() scan /proc/mounts over and over again. There is no caching. This causes a scaling issue in perf record with hugeltbfs__mountpoint(). The function is called for each process found in synthesize__mmap_events(). If the machine has thousands of processes and if the /proc/mounts has many entries this could cause major overhead in perf record. We have observed multi-second slowdowns on some configurations. As an example on a laptop: Before: $ sudo umount /dev/hugepages $ strace -e trace=openat -o /tmp/tt perf record -a ls $ fgrep mounts /tmp/tt 285 After: $ sudo umount /dev/hugepages $ strace -e trace=openat -o /tmp/tt perf record -a ls $ fgrep mounts /tmp/tt 1 One could argue that the non-caching in case the moint point is not found is intentional. That way subsequent calls may discover a moint point if the sysadmin mounts the filesystem. But the same argument could be made against caching the mount point. It could be unmounted causing errors. It all depends on the intent of the interface. This patch assumes it is expected to scan /proc/mounts once. The patch documents the caching behavior in the fs.h header file. An alternative would be to just fix perf record. But it would solve the problem with hugetlbs__mountpoint() but there could be similar issues (possibly down the line) with other xxx_mountpoint() calls in perf or other tools. Signed-off-by: Stephane Eranian Reviewed-by: Ian Rogers Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andrey Zhizhikin Cc: Kan Liang Cc: Kefeng Wang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Petr Mladek Cc: Thomas Gleixner Link: http://lore.kernel.org/lkml/20200402154357.107873-3-irogers@google.com Signed-off-by: Ian Rogers Signed-off-by: Arnaldo Carvalho de Melo

tools lib api fs: Move cgroupsfs_find_mountpoint()

2020-03-04T13:34:09Z

Move it from tools/perf/util/cgroup.c as it can be used by other places. Note that cgroup filesystem is different from others since it's usually mounted separately (in v1) for each subsystem. I just copied the code with a little modification to pass a name of subsystem. Suggested-by: Jiri Olsa Signed-off-by: Namhyung Kim Cc: Jiri Olsa Link: http://lore.kernel.org/lkml/20200127100031.1368732-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools lib api fs: Fix gcc9 stringop-truncation compilation error

2020-01-06T14:46:09Z

GCC9 introduced string hardening mechanisms, which exhibits the error during fs api compilation: error: '__builtin_strncpy' specified bound 4096 equals destination size [-Werror=stringop-truncation] This comes when the length of copy passed to strncpy is is equal to destination size, which could potentially lead to buffer overflow. There is a need to mitigate this potential issue by limiting the size of destination by 1 and explicitly terminate the destination with NULL. Signed-off-by: Andrey Zhizhikin Reviewed-by: Petr Mladek Acked-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Kefeng Wang Cc: Martin KaFai Lau Cc: Petr Mladek Cc: Sergey Senozhatsky Cc: Song Liu Cc: Yonghong Song Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: http://lore.kernel.org/lkml/20191211080109.18765-1-andrey.zhizhikin@leica-geosystems.com Signed-off-by: Arnaldo Carvalho de Melo

tools lib api: Renaming pr_warning to pr_warn

2019-10-18T13:02:57Z

For kernel logging macro, pr_warning is completely removed and replaced by pr_warn, using pr_warn in tools lib api for symmetry to kernel logging macro, then we could drop pr_warning in the whole linux code. Changing __pr_warning to __pr_warn to be consistent. Link: http://lkml.kernel.org/r/20191018031850.48498-30-wangkefeng.wang@huawei.com To: linux-kernel@vger.kernel.org Cc: Arnaldo Carvalho de Melo Signed-off-by: Kefeng Wang Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 251

2019-06-05T15:30:26Z

Based on 1 normalized pattern(s): released under the gpl v2 and only v2 not any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 12 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Steve Winslow Reviewed-by: Alexios Zavras Reviewed-by: Kate Stewart Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141332.526460839@linutronix.de Signed-off-by: Greg Kroah-Hartman