- 14 Jan, 2017 3 commits
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Jiri Olsa authored
It's possible to set up PEBS events to get only errors and not any data, like on SNB-X (model 45) and IVB-EP (model 62) via 2 perf commands running simultaneously: taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10 This leads to a soft lock up, because the error path of the intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt for error PEBS interrupts, so in case you're getting ONLY errors you don't have a way to stop the event when it's over the max_samples_per_tick limit: NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816] ... RIP: 0010:[<ffffffff81159232>] [<ffffffff81159232>] smp_call_function_single+0xe2/0x140 ... Call Trace: ? trace_hardirqs_on_caller+0xf5/0x1b0 ? perf_cgroup_attach+0x70/0x70 perf_install_in_context+0x199/0x1b0 ? ctx_resched+0x90/0x90 SYSC_perf_event_open+0x641/0xf90 SyS_perf_event_open+0x9/0x10 do_syscall_64+0x6c/0x1f0 entry_SYSCALL64_slow_path+0x25/0x25 Add perf_event_account_interrupt() which does the interrupt and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s error path. We keep the pending_kill and pending_wakeup logic only in the __perf_event_overflow() path, because they make sense only if there's any data to deliver. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> 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> Cc: Vince Weaver <vince@deater.net> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.orgSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
Di Shen reported a race between two concurrent sys_perf_event_open() calls where both try and move the same pre-existing software group into a hardware context. The problem is exactly that described in commit: f63a8daa ("perf: Fix event->ctx locking") ... where, while we wait for a ctx->mutex acquisition, the event->ctx relation can have changed under us. That very same commit failed to recognise sys_perf_event_context() as an external access vector to the events and thereby didn't apply the established locking rules correctly. So while one sys_perf_event_open() call is stuck waiting on mutex_lock_double(), the other (which owns said locks) moves the group about. So by the time the former sys_perf_event_open() acquires the locks, the context we've acquired is stale (and possibly dead). Apply the established locking rules as per perf_event_ctx_lock_nested() to the mutex_lock_double() for the 'move_group' case. This obviously means we need to validate state after we acquire the locks. Reported-by: Di Shen (Keen Lab) Tested-by: John Dias <joaodias@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Min Chong <mchong@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: f63a8daa ("perf: Fix event->ctx locking") Link: http://lkml.kernel.org/r/20170106131444.GZ3174@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Peter Zijlstra authored
There is problem with installing an event in a task that is 'stuck' on an offline CPU. Blocked tasks are not dis-assosciated from offlined CPUs, after all, a blocked task doesn't run and doesn't require a CPU etc.. Only on wakeup do we ammend the situation and place the task on a available CPU. If we hit such a task with perf_install_in_context() we'll loop until either that task wakes up or the CPU comes back online, if the task waking depends on the event being installed, we're stuck. While looking into this issue, I also spotted another problem, if we hit a task with perf_install_in_context() that is in the middle of being migrated, that is we observe the old CPU before sending the IPI, but run the IPI (on the old CPU) while the task is already running on the new CPU, things also go sideways. Rework things to rely on task_curr() -- outside of rq->lock -- which is rather tricky. Imagine the following scenario where we're trying to install the first event into our task 't': CPU0 CPU1 CPU2 (current == t) t->perf_event_ctxp[] = ctx; smp_mb(); cpu = task_cpu(t); switch(t, n); migrate(t, 2); switch(p, t); ctx = t->perf_event_ctxp[]; // must not be NULL smp_function_call(cpu, ..); generic_exec_single() func(); spin_lock(ctx->lock); if (task_curr(t)) // false add_event_to_ctx(); spin_unlock(ctx->lock); perf_event_context_sched_in(); spin_lock(ctx->lock); // sees event So its CPU0's store of t->perf_event_ctxp[] that must not go 'missing'. Because if CPU2's load of that variable were to observe NULL, it would not try to schedule the ctx and we'd have a task running without its counter, which would be 'bad'. As long as we observe !NULL, we'll acquire ctx->lock. If we acquire it first and not see the event yet, then CPU0 must observe task_curr() and retry. If the install happens first, then we must see the event on sched-in and all is well. I think we can translate the first part (until the 'must not be NULL') of the scenario to a litmus test like: C C-peterz { } P0(int *x, int *y) { int r1; WRITE_ONCE(*x, 1); smp_mb(); r1 = READ_ONCE(*y); } P1(int *y, int *z) { WRITE_ONCE(*y, 1); smp_store_release(z, 1); } P2(int *x, int *z) { int r1; int r2; r1 = smp_load_acquire(z); smp_mb(); r2 = READ_ONCE(*x); } exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0) Where: x is perf_event_ctxp[], y is our tasks's CPU, and z is our task being placed on the rq of CPU2. The P0 smp_mb() is the one added by this patch, ordering the store to perf_event_ctxp[] from find_get_context() and the load of task_cpu() in task_function_call(). The smp_store_release/smp_load_acquire model the RCpc locking of the rq->lock and the smp_mb() of P2 is the context switch switching from whatever CPU2 was running to our task 't'. This litmus test evaluates into: Test C-peterz Allowed States 7 0:r1=0; 2:r1=0; 2:r2=0; 0:r1=0; 2:r1=0; 2:r2=1; 0:r1=0; 2:r1=1; 2:r2=1; 0:r1=1; 2:r1=0; 2:r2=0; 0:r1=1; 2:r1=0; 2:r2=1; 0:r1=1; 2:r1=1; 2:r2=0; 0:r1=1; 2:r1=1; 2:r2=1; No Witnesses Positive: 0 Negative: 7 Condition exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0) Observation C-peterz Never 0 7 Hash=e427f41d9146b2a5445101d3e2fcaa34 And the strong and weak model agree. Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: jeremy.linton@arm.com Link: http://lkml.kernel.org/r/20161209135900.GU3174@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>
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- 11 Jan, 2017 2 commits
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Colin King authored
When x86_pmu.num_counters is 32 the shift of the integer constant 1 is exceeding 32bit and therefor undefined behaviour. Fix this by shifting 1ULL instead of 1. Reported-by: CoverityScan CID#1192105 ("Bad bit shift operation") Signed-off-by: Colin Ian King <colin.king@canonical.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kan Liang <kan.liang@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Link: http://lkml.kernel.org/r/20170111114310.17928-1-colin.king@canonical.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>
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Prarit Bhargava authored
hswep_uncore_cpu_init() uses a hardcoded physical package id 0 for the boot cpu. This works as long as the boot CPU is actually on the physical package 0, which is normaly the case after power on / reboot. But it fails with a NULL pointer dereference when a kdump kernel is started on a secondary socket which has a different physical package id because the locigal package translation for physical package 0 does not exist. Use the logical package id of the boot cpu instead of hard coded 0. [ tglx: Rewrote changelog once more ] Fixes: cf6d445f ("perf/x86/uncore: Track packages, not per CPU data") Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Harish Chegondi <harish.chegondi@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> 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> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1483628965-2890-1-git-send-email-prarit@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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- 05 Jan, 2017 2 commits
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David Carrillo-Cisneros authored
The conversion of Intel PMU drivers into modules did not include reference counting. The machine will crash when attempting to access deleted code if an event from a module PMU is started and the module removed before the event is destroyed. i.e. this crashes the machine: $ insmod intel-rapl-perf.ko $ perf stat -e power/energy-cores/ -C 0 & $ rmmod intel-rapl-perf.ko Set THIS_MODULE to pmu->module in Intel module PMUs so that generic code can handle reference counting and deny rmmod while an event still exists. Signed-off-by: David Carrillo-Cisneros <davidcc@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1482455860-116269-1-git-send-email-davidcc@google.comSigned-off-by: Ingo Molnar <mingo@kernel.org>
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Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo-4.10-20170104' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes and one improvement from Arnaldo Carvalho de Melo: Fixes: - Fix prev/next_prio formatting for deadline tasks in libtraceevent (Daniel Bristot de Oliveira) - Robustify reading of build-ids from /sys/kernel/note (Arnaldo Carvalho de Melo) - Fix building some sample/bpf in Alpine Linux 3.4 (Arnaldo Carvalho de Melo) - Fix 'make install-bin' to install libtraceevent plugins (Arnaldo Carvalho de Melo) - Fix 'perf record --switch-output' documentation and comment (Jiri Olsa) - Fix 'perf probe' for cross arch probing (Masami Hiramatsu) Improvement: - Show total scheduling time in 'perf sched timehist' (Namhyumg Kim) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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- 04 Jan, 2017 2 commits
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Masami Hiramatsu authored
Fix perf-probe to show probe definition on gcc generated symbols for offline kernel (including cross-arch kernel image). gcc sometimes optimizes functions and generate new symbols with suffixes such as ".constprop.N" or ".isra.N" etc. Since those symbol names are not recorded in DWARF, we have to find correct generated symbols from offline ELF binary to probe on it (kallsyms doesn't correct it). For online kernel or uprobes we don't need it because those are rebased on _text, or a section relative address. E.g. Without this: $ perf probe -k build-arm/vmlinux -F __slab_alloc* __slab_alloc.constprop.9 $ perf probe -k build-arm/vmlinux -D __slab_alloc p:probe/__slab_alloc __slab_alloc+0 If you put above definition on target machine, it should fail because there is no __slab_alloc in kallsyms. With this fix, perf probe shows correct probe definition on __slab_alloc.constprop.9: $ perf probe -k build-arm/vmlinux -D __slab_alloc p:probe/__slab_alloc __slab_alloc.constprop.9+0 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/148350060434.19001.11864836288580083501.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Masami Hiramatsu authored
Fix --funcs (-F) option to show correct symbols for offline module. Since previous perf-probe uses machine__findnew_module_map() for offline module, even if user passes a module file (with full path) which is for other architecture, perf-probe always tries to load symbol map for current kernel module. This fix uses dso__new_map() to load the map from given binary as same as a map for user applications. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/148350053478.19001.15435255244512631545.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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- 03 Jan, 2017 6 commits
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Arnaldo Carvalho de Melo authored
Markus reported that perf segfaults when reading /sys/kernel/notes from a kernel linked with GNU gold, due to what looks like a gold bug, so do some bounds checking to avoid crashing in that case. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Report-Link: http://lkml.kernel.org/r/20161219161821.GA294@x4 Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-ryhgs6a6jxvz207j2636w31c@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Arnaldo Carvalho de Melo authored
Those are binaries as well, so should be installed by: make -C tools/perf install-bin' too. Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/n/tip-3841b37u05evxrs1igkyu6ks@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Daniel Bristot de Oliveira authored
Currently, the sched:sched_switch tracepoint reports deadline tasks with priority -1. But when reading the trace via perf script I've got the following output: # ./d & # (d is a deadline task, see [1]) # perf record -e sched:sched_switch -a sleep 1 # perf script ... swapper 0 [000] 2146.962441: sched:sched_switch: swapper/0:0 [120] R ==> d:2593 [4294967295] d 2593 [000] 2146.972472: sched:sched_switch: d:2593 [4294967295] R ==> g:2590 [4294967295] The task d reports the wrong priority [4294967295]. This happens because the "int prio" is stored in an unsigned long long val. Although it is set as a %lld, as int is shorter than unsigned long long, trace_seq_printf prints it as a positive number. The fix is just to cast the val as an int, and print it as a %d, as in the sched:sched_switch tracepoint's "format". The output with the fix is: # ./d & # perf record -e sched:sched_switch -a sleep 1 # perf script ... swapper 0 [000] 4306.374037: sched:sched_switch: swapper/0:0 [120] R ==> d:10941 [-1] d 10941 [000] 4306.383823: sched:sched_switch: d:10941 [-1] R ==> swapper/0:0 [120] [1] d.c --- #include <stdio.h> #include <unistd.h> #include <sys/syscall.h> #include <linux/types.h> #include <linux/sched.h> struct sched_attr { __u32 size, sched_policy; __u64 sched_flags; __s32 sched_nice; __u32 sched_priority; __u64 sched_runtime, sched_deadline, sched_period; }; int sched_setattr(pid_t pid, const struct sched_attr *attr, unsigned int flags) { return syscall(__NR_sched_setattr, pid, attr, flags); } int main(void) { struct sched_attr attr = { .size = sizeof(attr), .sched_policy = SCHED_DEADLINE, /* This creates a 10ms/30ms reservation */ .sched_runtime = 10 * 1000 * 1000, .sched_period = attr.sched_deadline = 30 * 1000 * 1000, }; if (sched_setattr(0, &attr, 0) < 0) { perror("sched_setattr"); return -1; } for(;;); } --- Committer notes: Got the program from the provided URL, http://bristot.me/lkml/d.c, trimmed it and included in the cset log above, so that we have everything needed to test it in one place. Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/866ef75bcebf670ae91c6a96daa63597ba981f0d.1483443552.git.bristot@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Jiri Olsa authored
There's no --signal-trigger option, also adding the code comment into record man page. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1483431600-19887-4-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Jiri Olsa authored
There's no need for this one to be global. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Cc: David Ahern <dsahern@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1483431600-19887-3-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Jiri Olsa authored
To allow string options with a default argument and variable set when the option is used. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Wang Nan <wangnan0@huawei.com> Cc: David Ahern <dsahern@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1483431600-19887-2-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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- 02 Jan, 2017 1 commit
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Masami Hiramatsu authored
Since 'perf probe' supports cross-arch probes, it is possible to analyze different arch kernel image which has different bits-per-long. In that case, it fails to get the module name because it uses the MOD_NAME_OFFSET macro based on the host machine bits-per-long, instead of the target arch bits-per-long. This fixes above issue by changing modname-offset based on the target archs bit width. This is ok because linux kernel uses LP64 model on 64bit arch. E.g. without this (on x86_64, and target module is arm32): $ perf probe -m build-arm/fs/configfs/configfs.ko -D configfs_lookup p:probe/configfs_lookup :configfs_lookup+0 ^-Here is an empty module name. With this fix, you can see correct module name: $ perf probe -m build-arm/fs/configfs/configfs.ko -D configfs_lookup p:probe/configfs_lookup configfs:configfs_lookup+0 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/148337043836.6752.383495516397005695.stgit@devboxSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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- 01 Jan, 2017 2 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimmLinus Torvalds authored
Pull DAX updates from Dan Williams: "The completion of Jan's DAX work for 4.10. As I mentioned in the libnvdimm-for-4.10 pull request, these are some final fixes for the DAX dirty-cacheline-tracking invalidation work that was merged through the -mm, ext4, and xfs trees in -rc1. These patches were prepared prior to the merge window, but we waited for 4.10-rc1 to have a stable merge base after all the prerequisites were merged. Quoting Jan on the overall changes in these patches: "So I'd like all these 6 patches to go for rc2. The first three patches fix invalidation of exceptional DAX entries (a bug which is there for a long time) - without these patches data loss can occur on power failure even though user called fsync(2). The other three patches change locking of DAX faults so that ->iomap_begin() is called in a more relaxed locking context and we are safe to start a transaction there for ext4" These have received a build success notification from the kbuild robot, and pass the latest libnvdimm unit tests. There have not been any -next releases since -rc1, so they have not appeared there" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: ext4: Simplify DAX fault path dax: Call ->iomap_begin without entry lock during dax fault dax: Finish fault completely when loading holes dax: Avoid page invalidation races and unnecessary radix tree traversals mm: Invalidate DAX radix tree entries only if appropriate ext2: Return BH_New buffers for zeroed blocks
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- 30 Dec, 2016 2 commits
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git://git.lwn.net/linuxLinus Torvalds authored
Pull documentation fixes from Jonathan Corbet: "Two small fixes: - A merge error on my part broke the DocBook build. I've requisitioned one of tglx's frozen sharks for appropriate disciplinary action and resolved to be more careful about testing the DocBook stuff as long as it's still around. - Fix an error in unaligned-memory-access.txt" * tag 'docs-4.10-rc1-fix' of git://git.lwn.net/linux: Documentation/unaligned-memory-access.txt: fix incorrect comparison operator docs: Fix build failure
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
Pull crypto fix from Herbert Xu: "This fixes a boot failure on some platforms when crypto self test is enabled along with the new acomp interface" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: testmgr - Use heap buffer for acomp test input
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- 29 Dec, 2016 2 commits
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Olof Johansson authored
mm/filemap.c: In function 'clear_bit_unlock_is_negative_byte': mm/filemap.c:933:9: error: too few arguments to function 'test_bit' return test_bit(PG_waiters); ^~~~~~~~ Fixes: b91e1302 ('mm: optimize PageWaiters bit use for unlock_page()') Signed-off-by: Olof Johansson <olof@lixom.net> Brown-paper-bag-by: Linus Torvalds <dummy@duh.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
In commit 62906027 ("mm: add PageWaiters indicating tasks are waiting for a page bit") Nick Piggin made our page locking no longer unconditionally touch the hashed page waitqueue, which not only helps performance in general, but is particularly helpful on NUMA machines where the hashed wait queues can bounce around a lot. However, the "clear lock bit atomically and then test the waiters bit" sequence turns out to be much more expensive than it needs to be, because you get a nasty stall when trying to access the same word that just got updated atomically. On architectures where locking is done with LL/SC, this would be trivial to fix with a new primitive that clears one bit and tests another atomically, but that ends up not working on x86, where the only atomic operations that return the result end up being cmpxchg and xadd. The atomic bit operations return the old value of the same bit we changed, not the value of an unrelated bit. On x86, we could put the lock bit in the high bit of the byte, and use "xadd" with that bit (where the overflow ends up not touching other bits), and look at the other bits of the result. However, an even simpler model is to just use a regular atomic "and" to clear the lock bit, and then the sign bit in eflags will indicate the resulting state of the unrelated bit #7. So by moving the PageWaiters bit up to bit #7, we can atomically clear the lock bit and test the waiters bit on x86 too. And architectures with LL/SC (which is all the usual RISC suspects), the particular bit doesn't matter, so they are fine with this approach too. This avoids the extra access to the same atomic word, and thus avoids the costly stall at page unlock time. The only downside is that the interface ends up being a bit odd and specialized: clear a bit in a byte, and test the sign bit. Nick doesn't love the resulting name of the new primitive, but I'd rather make the name be descriptive and very clear about the limitation imposed by trying to work across all relevant architectures than make it be some generic thing that doesn't make the odd semantics explicit. So this introduces the new architecture primitive clear_bit_unlock_is_negative_byte(); and adds the trivial implementation for x86. We have a generic non-optimized fallback (that just does a "clear_bit()"+"test_bit(7)" combination) which can be overridden by any architecture that can do better. According to Nick, Power has the same hickup x86 has, for example, but some other architectures may not even care. All these optimizations mean that my page locking stress-test (which is just executing a lot of small short-lived shell scripts: "make test" in the git source tree) no longer makes our page locking look horribly bad. Before all these optimizations, just the unlock_page() costs were just over 3% of all CPU overhead on "make test". After this, it's down to 0.66%, so just a quarter of the cost it used to be. (The difference on NUMA is bigger, but there this micro-optimization is likely less noticeable, since the big issue on NUMA was not the accesses to 'struct page', but the waitqueue accesses that were already removed by Nick's earlier commit). Acked-by: Nick Piggin <npiggin@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Bob Peterson <rpeterso@redhat.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Andrew Lutomirski <luto@kernel.org> Cc: Andreas Gruenbacher <agruenba@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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- 28 Dec, 2016 5 commits
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Arnaldo Carvalho de Melo authored
Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Joe Stringer <joe@ovn.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-3awp0nv8tpnblatojmwjww7z@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
Pull crypto fix from Herbert Xu: "This fixes a hash corruption bug in the marvell driver" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: marvell - Copy IVDIG before launching partial DMA ahash requests
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Arnaldo Carvalho de Melo authored
To avoid the following build failure on Alpine Linux 3.4, that has clang-3.8 with the bpf target: HOSTCC samples/bpf/sock_example.o In file included from /usr/include/net/ethernet.h:10:0, from /git/linux/samples/bpf/sock_example.h:7, from /git/linux/samples/bpf/sock_example.c:30: /usr/include/netinet/if_ether.h:96:8: error: redefinition of 'struct ethhdr' struct ethhdr { ^ In file included from /git/linux/samples/bpf/sock_example.c:26:0: ./usr/include/linux/if_ether.h:144:8: note: originally defined here struct ethhdr { ^ scripts/Makefile.host:124: recipe for target 'samples/bpf/sock_example.o' failed make[2]: *** [samples/bpf/sock_example.o] Error 1 /git/linux/Makefile:1658: recipe for target 'samples/bpf/' failed So include net/if_ether.h for the needs of sock_example.h, using the same include that sock_example.c uses. Cc: Alexei Starovoitov <ast@fb.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Joe Stringer <joe@ovn.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-m9avekl1b651qe1r1zd5tzz9@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Namhyung Kim authored
Show length of analyzed sample time and rate of idle task running. This also takes care of time range given by --time option. $ perf sched timehist -sI | tail Samples do not have callchains. Idle stats: CPU 0 idle for 930.316 msec ( 92.93%) CPU 1 idle for 963.614 msec ( 96.25%) CPU 2 idle for 885.482 msec ( 88.45%) CPU 3 idle for 938.635 msec ( 93.76%) Total number of unique tasks: 118 Total number of context switches: 2337 Total run time (msec): 3718.048 Total scheduling time (msec): 1001.131 (x 4) Suggested-by: David Ahern <dsahern@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20161222060350.17655-3-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds authored
Pull networking fixes from David Miller: 1) Various ipvlan fixes from Eric Dumazet and Mahesh Bandewar. The most important is to not assume the packet is RX just because the destination address matches that of the device. Such an assumption causes problems when an interface is put into loopback mode. 2) If we retry when creating a new tc entry (because we dropped the RTNL mutex in order to load a module, for example) we end up with -EAGAIN and then loop trying to replay the request. But we didn't reset some state when looping back to the top like this, and if another thread meanwhile inserted the same tc entry we were trying to, we re-link it creating an enless loop in the tc chain. Fix from Daniel Borkmann. 3) There are two different WRITE bits in the MDIO address register for the stmmac chip, depending upon the chip variant. Due to a bug we could set them both, fix from Hock Leong Kweh. 4) Fix mlx4 bug in XDP_TX handling, from Tariq Toukan. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: net: stmmac: fix incorrect bit set in gmac4 mdio addr register r8169: add support for RTL8168 series add-on card. net: xdp: remove unused bfp_warn_invalid_xdp_buffer() openvswitch: upcall: Fix vlan handling. ipv4: Namespaceify tcp_tw_reuse knob net: korina: Fix NAPI versus resources freeing net, sched: fix soft lockup in tc_classify net/mlx4_en: Fix user prio field in XDP forward tipc: don't send FIN message from connectionless socket ipvlan: fix multicast processing ipvlan: fix various issues in ipvlan_process_multicast()
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- 27 Dec, 2016 13 commits
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Cihangir Akturk authored
In the actual implementation ether_addr_equal function tests for equality to 0 when returning. It seems in commit 0d74c4 it is somehow overlooked to change this operator to reflect the actual function. Signed-off-by: Cihangir Akturk <cakturk@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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John Brooks authored
The 80211.tmpl DocBook file was removed in commit 819bf593 ("docs-rst: sphinxify 802.11 documentation"), but the 80211.xml target was re-added to the Makefile by commit 7ddedebb ("ALSA: doc: ReSTize writing-an-alsa-driver document"), leading to a failure when building the documentation: *** No rule to make target 'Documentation/DocBook/80211.xml', needed by 'Documentation/DocBook/80211.aux.xml'. cc: stable@vger.kernel.org Signed-off-by: John Brooks <john@fastquake.com> Mea-culpa-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
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Jonathan Corbet authored
Linux 4.10-rc1
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Kweh, Hock Leong authored
Fixing the gmac4 mdio write access to use MII_GMAC4_WRITE only instead of OR together with MII_WRITE. Signed-off-by: Kweh, Hock Leong <hock.leong.kweh@intel.com> Acked-By: Joao Pinto <jpinto@synopsys.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Chun-Hao Lin authored
This chip is the same as RTL8168, but its device id is 0x8161. Signed-off-by: Chun-Hao Lin <hau@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Jason Wang authored
After commit 73b62bd0 ("virtio-net: remove the warning before XDP linearizing"), there's no users for bpf_warn_invalid_xdp_buffer(), so remove it. This is a revert for commit f23bc46c. Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
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pravin shelar authored
Networking stack accelerate vlan tag handling by keeping topmost vlan header in skb. This works as long as packet remains in OVS datapath. But during OVS upcall vlan header is pushed on to the packet. When such packet is sent back to OVS datapath, core networking stack might not handle it correctly. Following patch avoids this issue by accelerating the vlan tag during flow key extract. This simplifies datapath by bringing uniform packet processing for packets from all code paths. Fixes: 5108bbad ("openvswitch: add processing of L3 packets"). CC: Jarno Rajahalme <jarno@ovn.org> CC: Jiri Benc <jbenc@redhat.com> Signed-off-by: Pravin B Shelar <pshelar@ovn.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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Haishuang Yan authored
Different namespaces might have different requirements to reuse TIME-WAIT sockets for new connections. This might be required in cases where different namespace applications are in place which require TIME_WAIT socket connections to be reduced independently of the host. Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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Laura Abbott authored
Christopher Covington reported a crash on aarch64 on recent Fedora kernels: kernel BUG at ./include/linux/scatterlist.h:140! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 752 Comm: cryptomgr_test Not tainted 4.9.0-11815-ge93b1cc8 #162 Hardware name: linux,dummy-virt (DT) task: ffff80007c650080 task.stack: ffff800008910000 PC is at sg_init_one+0xa0/0xb8 LR is at sg_init_one+0x24/0xb8 ... [<ffff000008398db8>] sg_init_one+0xa0/0xb8 [<ffff000008350a44>] test_acomp+0x10c/0x438 [<ffff000008350e20>] alg_test_comp+0xb0/0x118 [<ffff00000834f28c>] alg_test+0x17c/0x2f0 [<ffff00000834c6a4>] cryptomgr_test+0x44/0x50 [<ffff0000080dac70>] kthread+0xf8/0x128 [<ffff000008082ec0>] ret_from_fork+0x10/0x50 The test vectors used for input are part of the kernel image. These inputs are passed as a buffer to sg_init_one which eventually blows up with BUG_ON(!virt_addr_valid(buf)). On arm64, virt_addr_valid returns false for the kernel image since virt_to_page will not return the correct page. Fix this by copying the input vectors to heap buffer before setting up the scatterlist. Reported-by: Christopher Covington <cov@codeaurora.org> Fixes: d7db7a88 ("crypto: acomp - update testmgr with support for acomp") Signed-off-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Jan Kara authored
Now that dax_iomap_fault() calls ->iomap_begin() without entry lock, we can use transaction starting in ext4_iomap_begin() and thus simplify ext4_dax_fault(). It also provides us proper retries in case of ENOSPC. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Jan Kara authored
Currently ->iomap_begin() handler is called with entry lock held. If the filesystem held any locks between ->iomap_begin() and ->iomap_end() (such as ext4 which will want to hold transaction open), this would cause lock inversion with the iomap_apply() from standard IO path which first calls ->iomap_begin() and only then calls ->actor() callback which grabs entry locks for DAX (if it faults when copying from/to user provided buffers). Fix the problem by nesting grabbing of entry lock inside ->iomap_begin() - ->iomap_end() pair. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Jan Kara authored
The only case when we do not finish the page fault completely is when we are loading hole pages into a radix tree. Avoid this special case and finish the fault in that case as well inside the DAX fault handler. It will allow us for easier iomap handling. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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Jan Kara authored
Currently dax_iomap_rw() takes care of invalidating page tables and evicting hole pages from the radix tree when write(2) to the file happens. This invalidation is only necessary when there is some block allocation resulting from write(2). Furthermore in current place the invalidation is racy wrt page fault instantiating a hole page just after we have invalidated it. So perform the page invalidation inside dax_iomap_actor() where we can do it only when really necessary and after blocks have been allocated so nobody will be instantiating new hole pages anymore. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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