- 02 Apr, 2015 20 commits
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Yunlong Song authored
Enable perf kvm to use perf.data.guest when it is not owned by current user or root. Example: # perf kvm stat record ls # chown Yunlong.Song:Yunlong.Song perf.data.guest # ls -al perf.data.guest -rw------- 1 Yunlong.Song Yunlong.Song 4128937 Apr 2 11:05 perf.data.guest # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf kvm stat report File perf.data.guest not owned by current user or root (use -f to override) Initializing perf session failed # perf kvm stat report -f Error: unknown switch `f' usage: perf kvm stat report [<options>] --event <report event> event for reporting: vmexit, mmio (x86 only), ioport (x86 only) --vcpu <n> vcpu id to report -k, --key <sort-key> key for sorting: sample(sort by samples number) time (sort by avg time) -p, --pid <pid> analyze events only for given process id(s) As shown above, the -f option does not work at all. After this patch: # perf kvm stat report File perf.data.guest not owned by current user or root (use -f to override) Initializing perf session failed # perf kvm stat report -f Analyze events for all VMs, all VCPUs: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time Total Samples:0, Total events handled time:0.00us. As shown above, the -f option really works now. Since we have not launched any KVM related process, the result shows 0 sample here. Signed-off-by:Yunlong Song <yunlong.song@huawei.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1427982439-27388-5-git-send-email-yunlong.song@huawei.comSigned-off-by:
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Yunlong Song authored
Enable perf kmem to use perf.data when it is not owned by current user or root. Example: # perf kmem record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 5315665 Apr 2 10:54 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf kmem stat File perf.data not owned by current user or root (use -f to override) # perf kmem stat -f Error: unknown switch `f' usage: perf kmem [<options>] {record|stat} -i, --input <file> input file name -v, --verbose be more verbose (show symbol address, etc) --caller show per-callsite statistics --alloc show per-allocation statistics -s, --sort <key[,key2...]> sort by keys: ptr, call_site, bytes, hit, pingpong, frag -l, --line <num> show n lines --raw-ip show raw ip instead of symbol As shown above, the -f option does not work at all. After this patch: # perf kmem stat File perf.data not owned by current user or root (use -f to override) # perf kmem stat -f SUMMARY ======= Total bytes requested: 437599 Total bytes allocated: 615472 Total bytes wasted on internal fragmentation: 177873 Internal fragmentation: 28.900259% Cross CPU allocations: 6/1192 As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf inject to use perf.data when it is not owned by current user or root. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:37 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf inject -v -b -i perf.data -o perf.data.new File perf.data not owned by current user or root (use -f to override) # perf inject -v -b -i perf.data -o perf.data.new -f Error: unknown switch `f' usage: perf inject [<options>] -b, --build-ids Inject build-ids into the output stream -i, --input <file> input file name -o, --output <file> output file name -s, --sched-stat Merge sched-stat and sched-switch for getting events where and how long tasks slept -v, --verbose be more verbose (show build ids, etc) --kallsyms <file> kallsyms pathname As shown above, the -f option does not work at all. After this patch: # perf inject -v -b -i perf.data -o perf.data.new File perf.data not owned by current user or root (use -f to override) # perf inject -v -b -i perf.data -o perf.data.new -f build id event received for [kernel.kallsyms]: f6dcb66d8b98f1c0d9eb87bf043444b69f91d30c symsrc__init: cannot get elf header. Looking at the vmlinux_path (7 entries long) Using /proc/kcore for kernel object code Using /proc/kallsyms for symbols As shown above, the -f option really works now. Signed-off-by: -
Yunlong Song authored
Enable perf evlist to use perf.data when it is not owned by current user or root. Example: # perf record ls # chown Yunlong.Song:Yunlong.Song perf.data # ls -al perf.data -rw------- 1 Yunlong.Song Yunlong.Song 28260 Apr 2 10:18 perf.data # id uid=0(root) gid=0(root) groups=0(root),64(pkcs11) Before this patch: # perf evlist File perf.data not owned by current user or root (use -f to override) # perf evlist -f Error: unknown switch `f' usage: perf evlist [<options>] -i, --input <file> Input file name -F, --freq Show the sample frequency -v, --verbose Show all event attr details -g, --group Show event group information As shown above, the -f option does not work at all. After this patch: # perf evlist File perf.data not owned by current user or root (use -f to override) # perf evlist -f cycles As shown above, the -f option really works now. Signed-off-by: -
Masami Hiramatsu authored
Fix 'perf probe' to track down unnamed union/structure members. perf probe did not track down the tree of unnamed union/structure members, since it just failed to find given "name" in a parent structure/union. To solve this issue, I've introduced 2 changes. - Fix die_find_member() to track down the type-DIE if it is unnamed, and if it contains the specified member, returns the unnamed member. (note that we don't return found member, since unnamed member has the offset in the parent structure) - Fix convert_variable_fields() to track down the unnamed union/ structure (one-by-one). With this patch, perf probe can access unnamed fields: ----- #./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops' Added new event: probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops) You can now use it in all perf tools, such as: perf record -e probe_perf:lock__delete -aR sleep 1 ----- Reported-by:Arnaldo Carvalho de Melo <acme@kernel.org> Report-Link: https://lkml.org/lkml/2015/3/5/431Signed-off-by:
Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by:
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Arnaldo Carvalho de Melo authored
As it comes from address_location->thread, that is already stored as export_sample->al, where the thread can be obtained. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20150402141542.GA9630@kernel.org Link: http://lkml.kernel.org/n/tip-bzotbl4epoztw0jd6sm2stpf@git.kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
As it is available via another parameter, address_location->thread. Acked-by:
Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: lkml.kernel.org/r/551D08F8.3040706@intel.com Link: http://lkml.kernel.org/n/tip-6dbn0tcm9hyv92g7h3zj2dbt@git.kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
It is already in the addr_location, so remove the redundant 'thread' parameter from the callback signatures. Acked-by:
Jiri Olsa <jolsa@redhat.com> Acked-by:
Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1427906210-10519-3-git-send-email-acme@kernel.orgSigned-off-by:
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Arnaldo Carvalho de Melo authored
We get the thread when we call perf_event__preprocess_sample(), no need to do it before that. Acked-by:
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Ingo Molnar authored
So bpf_tracing.o depends on CONFIG_BPF_SYSCALL - but that's not its only dependency, it also depends on the tracing infrastructure and on kprobes, without which it will fail to build with: In file included from kernel/trace/bpf_trace.c:14:0: kernel/trace/trace.h: In function ‘trace_test_and_set_recursion’: kernel/trace/trace.h:491:28: error: ‘struct task_struct’ has no member named ‘trace_recursion’ unsigned int val = current->trace_recursion; [...] It took quite some time to trigger this build failure, because right now BPF_SYSCALL is very obscure, depends on CONFIG_EXPERT. So also make BPF_SYSCALL more configurable, not just under CONFIG_EXPERT. If BPF_SYSCALL, tracing and kprobes are enabled then enable the bpf_tracing gateway as well. We might want to make this an interactive option later on, although I'd not complicate it unnecessarily: enabling BPF_SYSCALL is enough of an indicator that the user wants BPF support. Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: linux-kernel@vger.kernel.org Signed-off-by:Ingo Molnar <mingo@kernel.org>
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Alexei Starovoitov authored
One BPF program attaches to kmem_cache_alloc_node() and remembers all allocated objects in the map. Another program attaches to kmem_cache_free() and deletes corresponding object from the map. User space walks the map every second and prints any objects which are older than 1 second. Usage: $ sudo tracex4 Then start few long living processes. The 'tracex4' will print something like this: obj 0xffff880465928000 is 13sec old was allocated at ip ffffffff8105dc32 obj 0xffff88043181c280 is 13sec old was allocated at ip ffffffff8105dc32 obj 0xffff880465848000 is 8sec old was allocated at ip ffffffff8105dc32 obj 0xffff8804338bc280 is 15sec old was allocated at ip ffffffff8105dc32 $ addr2line -fispe vmlinux ffffffff8105dc32 do_fork at fork.c:1665 As soon as processes exit the memory is reclaimed and 'tracex4' prints nothing. Similar experiment can be done with the __kmalloc()/kfree() pair. Signed-off-by:
Alexei Starovoitov <ast@plumgrid.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1427312966-8434-10-git-send-email-ast@plumgrid.comSigned-off-by:
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Alexei Starovoitov authored
BPF C program attaches to blk_mq_start_request()/blk_update_request() kprobe events to calculate IO latency. For every completed block IO event it computes the time delta in nsec and records in a histogram map: map[log10(delta)*10]++ User space reads this histogram map every 2 seconds and prints it as a 'heatmap' using gray shades of text terminal. Black spaces have many events and white spaces have very few events. Left most space is the smallest latency, right most space is the largest latency in the range. Usage: $ sudo ./tracex3 and do 'sudo dd if=/dev/sda of=/dev/null' in other terminal. Observe IO latencies and how different activity (like 'make kernel') affects it. Similar experiments can be done for network transmit latencies, syscalls, etc. '-t' flag prints the heatmap using normal ascii characters: $ sudo ./tracex3 -t heatmap of IO latency # - many events with this latency - few events |1us |10us |100us |1ms |10ms |100ms |1s |10s *ooo. *O.#. # 221 . *# . # 125 .. .o#*.. # 55 . . . . .#O # 37 .# # 175 .#*. # 37 # # 199 . . *#*. # 55 *#..* # 42 # # 266 ...***Oo#*OO**o#* . # 629 # # 271 . .#o* o.*o* # 221 . . o* *#O.. # 50 Signed-off-by: -
Alexei Starovoitov authored
this example has two probes in one C file that attach to different kprove events and use two different maps. 1st probe is x64 specific equivalent of dropmon. It attaches to kfree_skb, retrevies 'ip' address of kfree_skb() caller and counts number of packet drops at that 'ip' address. User space prints 'location - count' map every second. 2nd probe attaches to kprobe:sys_write and computes a histogram of different write sizes Usage: $ sudo tracex2 location 0xffffffff81695995 count 1 location 0xffffffff816d0da9 count 2 location 0xffffffff81695995 count 2 location 0xffffffff816d0da9 count 2 location 0xffffffff81695995 count 3 location 0xffffffff816d0da9 count 2 557145+0 records in 557145+0 records out 285258240 bytes (285 MB) copied, 1.02379 s, 279 MB/s syscall write() stats byte_size : count distribution 1 -> 1 : 3 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 2 | | 32 -> 63 : 3 | | 64 -> 127 : 1 | | 128 -> 255 : 1 | | 256 -> 511 : 0 | | 512 -> 1023 : 1118968 |************************************* | Ctrl-C at any time. Kernel will auto cleanup maps and programs $ addr2line -ape ./bld_x64/vmlinux 0xffffffff81695995 0xffffffff816d0da9 0xffffffff81695995: ./bld_x64/../net/ipv4/icmp.c:1038 0xffffffff816d0da9: ./bld_x64/../net/unix/af_unix.c:1231 Signed-off-by:
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Alexei Starovoitov authored
tracex1_kern.c - C program compiled into BPF. It attaches to kprobe:netif_receive_skb() When skb->dev->name == "lo", it prints sample debug message into trace_pipe via bpf_trace_printk() helper function. tracex1_user.c - corresponding user space component that: - loads BPF program via bpf() syscall - opens kprobes:netif_receive_skb event via perf_event_open() syscall - attaches the program to event via ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); - prints from trace_pipe Note, this BPF program is non-portable. It must be recompiled with current kernel headers. kprobe is not a stable ABI and BPF+kprobe scripts may no longer be meaningful when kernel internals change. No matter in what way the kernel changes, neither the kprobe, nor the BPF program can ever crash or corrupt the kernel, assuming the kprobes, perf and BPF subsystem has no bugs. The verifier will detect that the program is using bpf_trace_printk() and the kernel will print 'this is a DEBUG kernel' warning banner, which means that bpf_trace_printk() should be used for debugging of the BPF program only. Usage: $ sudo tracex1 ping-19826 [000] d.s2 63103.382648: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63103.382684: : skb ffff880466b1d300 len 84 ping-19826 [000] d.s2 63104.382533: : skb ffff880466b1ca00 len 84 ping-19826 [000] d.s2 63104.382594: : skb ffff880466b1d300 len 84 Signed-off-by: -
Alexei Starovoitov authored
Debugging of BPF programs needs some form of printk from the program, so let programs call limited trace_printk() with %d %u %x %p modifiers only. Similar to kernel modules, during program load verifier checks whether program is calling bpf_trace_printk() and if so, kernel allocates trace_printk buffers and emits big 'this is debug only' banner. Signed-off-by:
Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: David S. Miller <davem@davemloft.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1427312966-8434-6-git-send-email-ast@plumgrid.comSigned-off-by:
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Alexei Starovoitov authored
bpf_ktime_get_ns() is used by programs to compute time delta between events or as a timestamp Signed-off-by:
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Alexei Starovoitov authored
BPF programs, attached to kprobes, provide a safe way to execute user-defined BPF byte-code programs without being able to crash or hang the kernel in any way. The BPF engine makes sure that such programs have a finite execution time and that they cannot break out of their sandbox. The user interface is to attach to a kprobe via the perf syscall: struct perf_event_attr attr = { .type = PERF_TYPE_TRACEPOINT, .config = event_id, ... }; event_fd = perf_event_open(&attr,...); ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); 'prog_fd' is a file descriptor associated with BPF program previously loaded. 'event_id' is an ID of the kprobe created. Closing 'event_fd': close(event_fd); ... automatically detaches BPF program from it. BPF programs can call in-kernel helper functions to: - lookup/update/delete elements in maps - probe_read - wraper of probe_kernel_read() used to access any kernel data structures BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is architecture dependent) and return 0 to ignore the event and 1 to store kprobe event into the ring buffer. Note, kprobes are a fundamentally _not_ a stable kernel ABI, so BPF programs attached to kprobes must be recompiled for every kernel version and user must supply correct LINUX_VERSION_CODE in attr.kern_version during bpf_prog_load() call. Signed-off-by: -
Alexei Starovoitov authored
add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of tracepoints, since bpf programs can only be attached to kprobe type of PERF_TYPE_TRACEPOINT perf events. Signed-off-by:
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Daniel Borkmann authored
Socket filter code and other subsystems with upcoming eBPF support should not need to deal with the fact that we have CONFIG_BPF_SYSCALL defined or not. Having the bpf syscall as a config option is a nice thing and I'd expect it to stay that way for expert users (I presume one day the default setting of it might change, though), but code making use of it should not care if it's actually enabled or not. Instead, hide this via header files and let the rest deal with it. Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Ingo Molnar authored
This WIP branch is now ready to be merged. Signed-off-by:
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- 01 Apr, 2015 1 commit
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Ingo Molnar authored
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible changes: - Fix 'perf script' pipe mode segfault, by always initializing ordered_events in perf_session__new(). (Arnaldo Carvalho de Melo) - Fix ppid for synthesized fork events. (David Ahern) - Fix kernel symbol resolution of callchains in S/390 by remembering the cpumode. (David Hildenbrand) Infrastructure changes: - Disable libbabeltrace check by default in the build system. (Jiri Olsa) Signed-off-by:
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- 31 Mar, 2015 5 commits
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Arnaldo Carvalho de Melo authored
As these can be obtained from the ordered_events pointer, via container_of, reducing the cross section of ordered_samples. These were added to ordered_samples in: commit b7b61cbe Author: Arnaldo Carvalho de Melo <acme@redhat.com> Date: Tue Mar 3 11:58:45 2015 -0300 perf ordered_events: Shorten function signatures By keeping pointers to machines, evlist and tool in ordered_events. But that was more a transitional patch while moving stuff out from perf_session.c to ordered_events.c and possibly not even needed by then, as we could use the container_of() method and instead of having the nr_unordered_samples stats in events_stats, we can have it in ordered_samples. Based-on-a-patch-by:
Jiri Olsa <jolsa@kernel.org> Acked-by:
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Arnaldo Carvalho de Melo authored
Even when it is not used to actually reorder events, some of its fields are used, like session->ordered_events->tool, to shorten function signatures where tool, for instance, was being passed, as the tool is needed for the ordered_events code, we need it there and might as well use it for other perf_session needs. This fixes a problem where 'perf script' had some condition that made session->ordered_events not to be initialized even with its script->tool ordered_events related flags asking for it to be, which looks like another bug and needs to be investigated further. Always initializing session->ordered_events at least leaves the current assumptions in place, so do it now. Reported-by:
David Ahern <dsahern@gmail.com> Reviewed-by:
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David Ahern authored
363b785f added synthesized fork events and set a thread's parent id to itself. Since we are already processing /proc/<pid>/status the ppid can be determined properly. Make it so. Signed-off-by:
Don Zickus <dzickus@redhat.com> Acked-by:
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David Ahern authored
Rather than parsing /proc/pid/status file one line at a time, read it into a buffer in one shot and search for all strings in one pass. tgid conversion also simplified -- removing the isspace walk. As noted by Arnaldo those are not needed for atoi == strtol calls. Signed-off-by:
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David Hildenbrand authored
Commit 2e77784b ("perf callchain: Move cpumode resolve code to add_callchain_ip") promised "No change in behavior.". As this commit breaks callchains on s390x (symbols not getting resolved, observed when profiling the kernel), this statement is wrong. The cpumode must be kept when iterating over all ips, otherwise the default (PERF_RECORD_MISC_USER) will be used by error. Signed-off-by:
David Hildenbrand <dahi@linux.vnet.ibm.com> Acked-by:
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- 30 Mar, 2015 1 commit
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Jiri Olsa authored
Disabling libbabeltrace check by default and replacing the NO_LIBBABELTRACE make variable with LIBBABELTRACE. Users wanting the libbabeltrace feature need to build via: $ make LIBBABELTRACE=1 The reason for this is that the libababeltrace interface we use (version 1.3) hasn't been packaged/released yet, thus the failing feature check only slows down build and confuses other (non CTF) developers. Requested-by:
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- 27 Mar, 2015 13 commits
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Peter Zijlstra authored
While thinking on the whole clock discussion it occurred to me we have two distinct uses of time: 1) the tracking of event/ctx/cgroup enabled/running/stopped times which includes the self-monitoring support in struct perf_event_mmap_page. 2) the actual timestamps visible in the data records. And we've been conflating them. The first is all about tracking time deltas, nobody should really care in what time base that happens, its all relative information, as long as its internally consistent it works. The second however is what people are worried about when having to merge their data with external sources. And here we have the discussion on MONOTONIC vs MONOTONIC_RAW etc.. Where MONOTONIC is good for correlating between machines (static offset), MONOTNIC_RAW is required for correlating against a fixed rate hardware clock. This means configurability; now 1) makes that hard because it needs to be internally consistent across groups of unrelated events; which is why we had to have a global perf_clock(). However, for 2) it doesn't really matter, perf itself doesn't care what it writes into the buffer. The below patch makes the distinction between these two cases by adding perf_event_clock() which is used for the second case. It further makes this configurable on a per-event basis, but adds a few sanity checks such that we cannot combine events with different clocks in confusing ways. And since we then have per-event configurability we might as well retain the 'legacy' behaviour as a default. Signed-off-by:Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Ingo Molnar authored
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Ingo Molnar authored
An upcoming patch will depend on tai_ns() and NMI-safe ktime_get_raw_fast(), so merge timers/core here in a separate topic branch until it's all cooked and timers/core is merged upstream. Signed-off-by: -
Peter Zijlstra authored
While looking at some fuzzer output I noticed that we do not hold any locks on leader->ctx and therefore the sibling_list iteration is unsafe. Acquire the relevant ctx->mutex before calling into the pmu specific code. Signed-off-by:
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David Ahern authored
perf_pmu_disable() is called before pmu->add() and perf_pmu_enable() is called afterwards. No need to call these inside of x86_pmu_add() as well. Signed-off-by:
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Ingo Molnar authored
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Ingo Molnar authored
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Peter Zijlstra authored
Because it was the only clock for which we didn't have a _ns() accessor yet. Signed-off-by:
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Peter Zijlstra authored
Add the NMI safe CLOCK_MONOTONIC_RAW accessor.. Signed-off-by:
John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150319093400.562746929@infradead.orgSigned-off-by:
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Peter Zijlstra authored
In preparation for more tk_fast instances, remove all hard-coded tk_fast_mono references. Signed-off-by:
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Peter Zijlstra authored
Introduce tkr_raw and make use of it. base_raw -> tkr_raw.base clock->{mult,shift} -> tkr_raw.{mult.shift} Kill timekeeping_get_ns_raw() in favour of timekeeping_get_ns(&tkr_raw), this removes all mono_raw special casing. Duplicate the updates to tkr_mono.cycle_last into tkr_raw.cycle_last, both need the same value. Signed-off-by: -
Peter Zijlstra authored
In preparation of adding another tkr field, rename this one to tkr_mono. Also rename tk_read_base::base_mono to tk_read_base::base, since the structure is not specific to CLOCK_MONOTONIC and the mono name got added to the tk_read_base instance. Lots of trivial churn. Signed-off-by:
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Andi Kleen authored
On Broadwell INST_RETIRED.ALL cannot be used with any period that doesn't have the lowest 6 bits cleared. And the period should not be smaller than 128. This is erratum BDM11 and BDM55: http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/5th-gen-core-family-spec-update.pdf BDM11: When using a period < 100; we may get incorrect PEBS/PMI interrupts and/or an invalid counter state. BDM55: When bit0-5 of the period are !0 we may get redundant PEBS records on overflow. Add a new callback to enforce this, and set it for Broadwell. How does this handle the case when an app requests a specific period with some of the bottom bits set? Short answer: Any useful instruction sampling period needs to be 4-6 orders of magnitude larger than 128, as an PMI every 128 instructions would instantly overwhelm the system and be throttled. So the +-64 error from this is really small compared to the period, much smaller than normal system jitter. Long answer (by Peterz): IFF we guarantee perf_event_attr::sample_period >= 128. Suppose we start out with sample_period=192; then we'll set period_left to 192, we'll end up with left = 128 (we truncate the lower bits). We get an interrupt, find that period_left = 64 (>0 so we return 0 and don't get an overflow handler), up that to 128. Then we trigger again, at n=256. Then we find period_left = -64 (<=0 so we return 1 and do get an overflow). We increment with sample_period so we get left = 128. We fire again, at n=384, period_left = 0 (<=0 so we return 1 and get an overflow). And on and on. So while the individual interrupts are 'wrong' we get then with interval=256,128 in exactly the right ratio to average out at 192. And this works for everything >=128. So the num_samples*fixed_period thing is still entirely correct +- 127, which is good enough I'd say, as you already have that error anyhow. So no need to 'fix' the tools, al we need to do is refuse to create INST_RETIRED:ALL events with sample_period < 128. Signed-off-by:
Andi Kleen <ak@linux.intel.com> [ Updated comments and changelog a bit. ] Signed-off-by:
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