talos-op-linux/tools/perf/arch/s390/util, branch master

perf tools: Avoid 'sample_reg_masks' being const + weak

2019-10-10T12:29:33+00:00

Being const + weak breaks with some compilers that constant-propagate from the weak symbol. This behavior is outside of the specification, but in LLVM is chosen to match GCC's behavior. LLVM's implementation was set in this patch: https://github.com/llvm/llvm-project/commit/f49573d1eedcf1e44893d5a062ac1b72c8419646 A const + weak symbol is set to be weak_odr: https://llvm.org/docs/LangRef.html ODR is one definition rule, and given there is one constant definition constant-propagation is possible. It is possible to get this code to miscompile with LLVM when applying link time optimization. As compilers become more aggressive, this is likely to break in more instances. Move the definition of sample_reg_masks to the conditional part of perf_regs.h and guard usage with HAVE_PERF_REGS_SUPPORT. This avoids the weak symbol. Fix an issue when HAVE_PERF_REGS_SUPPORT isn't defined from patch v1. In v3, add perf_regs.c for architectures that HAVE_PERF_REGS_SUPPORT but don't declare sample_regs_masks. Further notes: Jiri asked: "Is this just a precaution or you actualy saw some breakage?" Ian answered: "We saw a breakage with clang with thinlto enabled for linking. Our compiler team had recently seen, and were surprised by, a similar issue and were able to dig out the weak ODR issue." Signed-off-by: Ian Rogers Reviewed-by: Nick Desaulniers Acked-by: Jiri Olsa Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexey Budankov Cc: Andi Kleen Cc: clang-built-linux@googlegroups.com Cc: Guo Ren Cc: Kan Liang Cc: linux-riscv@lists.infradead.org Cc: Mao Han Cc: Mark Rutland Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20191001003623.255186-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Propagate get_cpuid() error

2019-09-30T20:29:54+00:00

For consistency, propagate the exact cause for get_cpuid() to have failed. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-9ig269f7ktnhh99g4l15vpu2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

libperf: Move 'page_size' global variable to libperf

2019-09-25T12:51:48+00:00

We need the 'page_size' variable in libperf, so move it there. Add a libperf_init() as a global libperf init function to obtain this value via sysconf() at tool start. Committer notes: Add internal/lib.h to tools/perf/ files using 'page_size', sometimes replacing util.h with it if that was the only reason for having util.h included. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20190913132355.21634-33-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Adopt backwards ring buffer state enum

2019-09-25T12:51:45+00:00

As this isn't used at all in mmap.h but in evlist.h, so to cut down the header dependency tree, move it to where it is used. Also add mmap.h to the places using it but previously getting it indirectly via evlist.h. Add missing pthread.h to evlist.h, as it has a pthread_t struct member and was getting the header via mmap.h. Noticed while processing a Jiri's libperf batch touching mmap.h, where almost everything gets rebuilt because evlist.h is so popular, so cut down't this rebuild the world party. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Cc: Song Liu Link: https://lkml.kernel.org/n/tip-he0uljeftl0xfveh3d6vtode@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove util.h from where it is not needed

2019-09-20T12:19:20+00:00

Check that it is not needed and remove, fixing up some fallout for places where it was only serving to get something else. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-9h6dg6lsqe2usyqjh5rrues4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

libperf: Rename the PERF_RECORD_ structs to have a "perf" prefix

2019-08-29T11:36:12+00:00

Even more, to have a "perf_record_" prefix, so that they match the PERF_RECORD_ enum they map to. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20190828135717.7245-23-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Move record_opts and other record decls out of perf.h

2019-08-26T14:58:22+00:00

And into a separate util/record.h, to better isolate things and make sure that those who use record_opts and the other moved declarations are explicitly including the necessary header. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-31q8mei1qkh74qvkl9nwidfq@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf kvm s390: Add missing string.h header

2019-08-22T20:16:56+00:00

It uses strstr(), needs to include string.h or its not going to build when we remove string.h from the place it is getting from indirectly, by luck. Cc: Adrian Hunter Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lkml.kernel.org/n/tip-72y0i0uiaqght5b83e3ae7p4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

Merge remote-tracking branch 'torvalds/master' into perf/core

2019-08-12T19:25:00+00:00

To get closer to upstream and check if we need to sync more UAPI headers, pick up fixes for libbpf that prevent perf's container tests from completing successfuly, etc. Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Fix s390 gap between kernel end and module start

2019-08-08T18:41:25+00:00

During execution of command 'perf top' the error message: Not enough memory for annotating '__irf_end' symbol!) is emitted from this call sequence: __cmd_top perf_top__mmap_read perf_top__mmap_read_idx perf_event__process_sample hist_entry_iter__add hist_iter__top_callback perf_top__record_precise_ip hist_entry__inc_addr_samples symbol__inc_addr_samples symbol__get_annotation symbol__alloc_hist In this function the size of symbol __irf_end is calculated. The size of a symbol is the difference between its start and end address. When the symbol was read the first time, its start and end was set to: symbol__new: __irf_end 0xe954d0-0xe954d0 which is correct and maps with /proc/kallsyms: root@s8360046:~/linux-4.15.0/tools/perf# fgrep _irf_end /proc/kallsyms 0000000000e954d0 t __irf_end root@s8360046:~/linux-4.15.0/tools/perf# In function symbol__alloc_hist() the end of symbol __irf_end is symbol__alloc_hist sym:__irf_end start:0xe954d0 end:0x3ff80045a8 which is identical with the first module entry in /proc/kallsyms This results in a symbol size of __irf_req for histogram analyses of 70334140059072 bytes and a malloc() for this requested size fails. The root cause of this is function __dso__load_kallsyms() +-> symbols__fixup_end() Function symbols__fixup_end() enlarges the last symbol in the kallsyms map: # fgrep __irf_end /proc/kallsyms 0000000000e954d0 t __irf_end # to the start address of the first module: # cat /proc/kallsyms | sort | egrep ' [tT] ' .... 0000000000e952d0 T __security_initcall_end 0000000000e954d0 T __initramfs_size 0000000000e954d0 t __irf_end 000003ff800045a8 T fc_get_event_number [scsi_transport_fc] 000003ff800045d0 t store_fc_vport_disable [scsi_transport_fc] 000003ff800046a8 T scsi_is_fc_rport [scsi_transport_fc] 000003ff800046d0 t fc_target_setup [scsi_transport_fc] On s390 the kernel is located around memory address 0x200, 0x10000 or 0x100000, depending on linux version. Modules however start some- where around 0x3ff xxxx xxxx. This is different than x86 and produces a large gap for which histogram allocation fails. Fix this by detecting the kernel's last symbol and do no adjustment for it. Introduce a weak function and handle s390 specifics. Reported-by: Klaus Theurich Signed-off-by: Thomas Richter Acked-by: Heiko Carstens Cc: Hendrik Brueckner Cc: Vasily Gorbik Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20190724122703.3996-2-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo