kernel/tools/perf, branch linux-4.3.y

perf tools: Fix build break on powerpc due to sample_reg_masks

2015-10-07T13:20:08Z

perf_regs.c does not get built on Powerpc as CONFIG_PERF_REGS is false. So the weak definition for 'sample_regs_masks' doesn't get picked up. Adding perf_regs.o to util/Build unconditionally, exposes a redefinition error for 'perf_reg_value()' function (due to the static inline version in util/perf_regs.h). So use #ifdef HAVE_PERF_REGS_SUPPORT' around that function. Signed-off-by: Sukadev Bhattiprolu Acked-by: Jiri Olsa Cc: Naveen N. Rao Cc: Stephane Eranian Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20150930182836.GA27858@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix copying of /proc/kcore

2015-09-25T13:45:50Z

A copy of /proc/kcore containing the kernel text can be made to the buildid cache. e.g. perf buildid-cache -v -k /proc/kcore To workaround objdump limitations, a copy is also made when annotating against /proc/kcore. The copying process stops working from libelf about v1.62 onwards (the problem was found with v1.63). The cause is that a call to gelf_getphdr() in kcore__add_phdr() fails because additional validation has been added to gelf_getphdr(). The use of gelf_getphdr() is a misguided attempt to get default initialization of the Gelf_Phdr structure. That should not be necessary because every member of the Gelf_Phdr structure is subsequently assigned. So just remove the call to gelf_getphdr(). Similarly, a call to gelf_getehdr() in gelf_kcore__init() can be removed also. Committer notes: Note to stable@kernel.org, from Adrian in the cover letter for this patchkit: The "Fix copying of /proc/kcore" problem goes back to v3.13 if you think it is important enough for stable. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@kernel.org Link: http://lkml.kernel.org/r/1443089122-19082-3-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf intel-pt: Remove no_force_psb from documentation

2015-09-25T13:42:38Z

no_force_psb was dropped as a late change to the kernel driver. Consequently, remove it from the documentation. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Link: http://lkml.kernel.org/r/1443089122-19082-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Use existing routine to look for a kernel module by dso->short_name

2015-09-25T13:41:31Z

We have map_groups__find_by_name() to look at the list of modules that are in place for a given machine, so use it instead of traversing the machine dso list, which also includes DSOs for userspace. When merging the user and kernel DSO lists a bug was introduced where 'perf probe' stopped being able to add probes to modules using its short name: # perf probe -m usbnet --add usbnet_start_xmit usbnet_start_xmit is out of .text, skip it. Error: Failed to add events. # With this fix it works again: # perf probe -m usbnet --add usbnet_start_xmit Added new event: probe:usbnet_start_xmit (on usbnet_start_xmit in usbnet) You can now use it in all perf tools, such as: perf record -e probe:usbnet_start_xmit -aR sleep 1 # Reported-by: Wang Nan Acked-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Fixes: 3d39ac538629 ("perf machine: No need to have two DSOs lists") Link: http://lkml.kernel.org/r/20150924015008.GE1897@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Avoid infinite loop at buildid processing with no samples

2015-09-18T15:31:40Z

If a session contains no events, we can get stuck in an infinite loop in __perf_session__process_events, with a non-zero file_size and data_offset, but a zero data_size. In this case, we can mmap the entirety of the file (consisting of the file and attribute headers), and fetch_mmaped_event will correctly refuse to read any (unmapped and non-existent) event headers. This causes __perf_session__process_events to unmap the file and retry with the exact same parameters, getting stuck in an infinite loop. This has been observed to result in an exit-time hang when counting rare/unschedulable events with perf record, and can be triggered artificially with the script below: ---- #!/bin/sh printf "REPRO: launching perf\n"; ./perf record -e software/config=9/ sleep 1 & PERF_PID=$!; sleep 0.002; kill -2 $PERF_PID; printf "REPRO: waiting for perf (%d) to exit...\n" "$PERF_PID"; wait $PERF_PID; printf "REPRO: perf exited\n"; ---- To avoid this, have __perf_session__process_events bail out early when the file has no data (i.e. it has no events). Commiter note: I only managed to reproduce this when setting /proc/sys/kernel/kptr_restrict to '1' and changing the code to purposefully not process any samples and no synthesized samples, i.e. kptr_restrict prevents 'record' from synthesizing the kernel mmaps for vmlinux + modules and since it is a workload started from perf, we don't synthesize mmap/comm records for existing threads. Adrian Hunter managed to reproduce it in his environment tho. Signed-off-by: Mark Rutland Tested-by: Arnaldo Carvalho de Melo Tested-by: Adrian Hunter Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1442423929-12253-1-git-send-email-mark.rutland@arm.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Bool functions shouldn't return -1

2015-09-17T18:31:52Z

Returning a negative value for a boolean function seem to have the undesired effect of returning true. Replace -1 by false in a bool-returning function. The diff of the .s file before and after the change (for x86_64): 3907c3907 < movl $1, %ebx --- > xorl %ebx, %ebx while if -1 is replaced by true, the diff is empty. This issue was found by the following Coccinelle semantic patch: @@ identifier f; constant C; typedef bool; @@ bool f (...){ <+... * return -C; ...+> } Signed-off-by: Peter Senna Tschudin Cc: Jiri Olsa Cc: Kan Liang Cc: Matt Fleming Cc: Milos Vyletel Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1442484533-19742-1-git-send-email-peter.senna@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add test for presence of __get_cpuid() gcc builtin

2015-09-17T16:14:35Z

The auxtrace code needed by Intel PT uses the __get_cpuid() gcc builtin, that is not present in old systems, breaking the build. Add a test to check for that builtin and disable AUXTRACE in those systems. [acme@rhel5 linux]$ make NO_LIBPERL=1 -C tools/perf O=/tmp/build/perf install-bin make: Entering directory `/home/acme/git/linux/tools/perf' BUILD: Doing 'make -j2' parallel build Auto-detecting system features: ... lzma: [ on ] ... get_cpuid: [ OFF ] config/Makefile:630: Your gcc lacks the __get_cpuid() builtin, disables support for auxtrace/Intel PT, please install a newer gcc MKDIR /tmp/build/perf/util/ This fixes the build on old systems such as RHEL/CentOS 5.11. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: "Naveen N. Rao" Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Stephane Eranian Cc: Victor Kamensky Cc: Vinson Lee Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-d4puslul0jltoodzpx9r4sje@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add test for presence of numa_num_possible_cpus() in libnuma

2015-09-17T16:14:35Z

The existing numa test checks only if numa.h and numa_available() are present, but that can be satisfied with an old libnuma that is not enough for the 'perf bench numa' entry, so add a test to check for that: [acme@rhel5 linux]$ make NO_AUXTRACE=1 NO_LIBPERL=1 -C tools/perf O=/tmp/build/perf install-bin make: Entering directory `/home/acme/git/linux/tools/perf' BUILD: Doing 'make -j2' parallel build Auto-detecting system features: ... libelf: [ on ] ... libnuma: [ on ] ... numa_num_possible_cpus: [ OFF ] ... libperl: [ on ] config/Makefile:577: Old numa library found, disables 'perf bench numa mem' benchmark, please install numactl-devel/libnuma-devel/libnuma-dev >= 2.0.8 INSTALL binaries This fixes the build on old systems such as RHEL/CentOS 5.11. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: "Naveen N. Rao" Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Stephane Eranian Cc: Victor Kamensky Cc: Vinson Lee Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-zqriqkezppi2de2iyjin1tnc@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

Revert "perf symbols: Fix mismatched declarations for elf_getphdrnum"

2015-09-17T16:10:05Z

This reverts commit f785f2357673d520a0b7b468973cdd197f336494. We have a test to check if elf_getphdrnum() is present, so, if it fails, we'll get: [acme@rhel5 linux]$ cat /tmp/build/perf/feature/test-libelf-getphdrnum.make.output cc1: warnings being treated as errors test-libelf-getphdrnum.c: In function ‘main’: test-libelf-getphdrnum.c:7: warning: implicit declaration of function ‘elf_getphdrnum’ [acme@rhel5 linux]$ And this block will not be compiled: #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT static int elf_getphdrnum(Elf *elf, size_t *dst) ... #endif So, if elf_getphdrnum() is being defined somewhere, there is a problem with the test that is not detecting that function, go fix it. Reported-by: Vinson Lee Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: "Naveen N. Rao" Cc: Peter Zijlstra Cc: Srikar Dronamraju Cc: Stephane Eranian Cc: Victor Kamensky Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-qn459fal6acvcvm50i8zxx9k@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Fix per-pkg event reporting bug

2015-09-16T21:01:03Z

Per-pkg events need to be captured once per processor socket. The code in check_per_pkg() ensures only one value per processor package is used. However there is a problem with this function in case the first CPU of the package does not measure anything for the per-pkg event, but other CPUs do. Consider the following: $ create cgroup FOO; echo $$ >FOO/tasks; taskset -c 1 noploop & $ perf stat -a -I 1000 -e intel_cqm/llc_occupancy/ -G FOO sleep 100 1.00000 Bytes intel_cqm/llc_occupancy/ FOO The reason for this is that CPU0 in the cgroup has nothing running on it. Yet check_per_plg() will mark socket0 as processed and no other event value will be considered for the socket. This patch fixes the problem by having check_per_pkg() only consider events which actually ran. Signed-off-by: Stephane Eranian Cc: Adrian Hunter Cc: Andi Kleen Cc: David Ahern Cc: Jiri Olsa Cc: Kan Liang Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1441286620-10117-1-git-send-email-eranian@google.com Signed-off-by: Arnaldo Carvalho de Melo