1. 02 4月, 2015 14 次提交
    • A
      perf: Add wakeup watermark control to the AUX area · 1a594131
      Alexander Shishkin 提交于
      When AUX area gets a certain amount of new data, we want to wake up
      userspace to collect it. This adds a new control to specify how much
      data will cause a wakeup. This is then passed down to pmu drivers via
      output handle's "wakeup" field, so that the driver can find the nearest
      point where it can generate an interrupt.
      
      We repurpose __reserved_2 in the event attribute for this, even though
      it was never checked to be zero before, aux_watermark will only matter
      for new AUX-aware code, so the old code should still be fine.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-10-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1a594131
    • A
      perf: Support overwrite mode for the AUX area · 2023a0d2
      Alexander Shishkin 提交于
      This adds support for overwrite mode in the AUX area, which means "keep
      collecting data till you're stopped", turning AUX area into a circular
      buffer, where new data overwrites old data. It does not depend on data
      buffer's overwrite mode, so that it doesn't lose sideband data that is
      instrumental for processing AUX data.
      
      Overwrite mode is enabled at mapping AUX area read only. Even though
      aux_tail in the buffer's user page might be user writable, it will be
      ignored in this mode.
      
      A PERF_RECORD_AUX with PERF_AUX_FLAG_OVERWRITE set is written to the perf
      data stream every time an event writes new data to the AUX area. The pmu
      driver might not be able to infer the exact beginning of the new data in
      each snapshot, some drivers will only provide the tail, which is
      aux_offset + aux_size in the AUX record. Consumer has to be able to tell
      the new data from the old one, for example, by means of time stamps if
      such are provided in the trace.
      
      Consumer is also responsible for disabling any events that might write
      to the AUX area (thus potentially racing with the consumer) before
      collecting the data.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-9-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2023a0d2
    • A
      perf: Add API for PMUs to write to the AUX area · fdc26706
      Alexander Shishkin 提交于
      For pmus that wish to write data to ring buffer's AUX area, provide
      perf_aux_output_{begin,end}() calls to initiate/commit data writes,
      similarly to perf_output_{begin,end}. These also use the same output
      handle structure. Also, similarly to software counterparts, these
      will direct inherited events' output to parents' ring buffers.
      
      After the perf_aux_output_begin() returns successfully, handle->size
      is set to the maximum amount of data that can be written wrt aux_tail
      pointer, so that no data that the user hasn't seen will be overwritten,
      therefore this should always be called before hardware writing is
      enabled. On success, this will return the pointer to pmu driver's
      private structure allocated for this aux area by pmu::setup_aux. Same
      pointer can also be retrieved using perf_get_aux() while hardware
      writing is enabled.
      
      PMU driver should pass the actual amount of data written as a parameter
      to perf_aux_output_end(). All hardware writes should be completed and
      visible before this one is called.
      
      Additionally, perf_aux_output_skip() will adjust output handle and
      aux_head in case some part of the buffer has to be skipped over to
      maintain hardware's alignment constraints.
      
      Nested writers are forbidden and guards are in place to catch such
      attempts.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-8-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      fdc26706
    • A
      perf: Add AUX record · 68db7e98
      Alexander Shishkin 提交于
      When there's new data in the AUX space, output a record indicating its
      offset and size and a set of flags, such as PERF_AUX_FLAG_TRUNCATED, to
      mean the described data was truncated to fit in the ring buffer.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-7-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      68db7e98
    • A
      perf: Add a pmu capability for "exclusive" events · bed5b25a
      Alexander Shishkin 提交于
      Usually, pmus that do, for example, instruction tracing, would only ever
      be able to have one event per task per cpu (or per perf_event_context). For
      such pmus it makes sense to disallow creating conflicting events early on,
      so as to provide consistent behavior for the user.
      
      This patch adds a pmu capability that indicates such constraint on event
      creation.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1422613866-113186-1-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      bed5b25a
    • A
      perf: Add a capability for AUX_NO_SG pmus to do software double buffering · 6a279230
      Alexander Shishkin 提交于
      For pmus that don't support scatter-gather for AUX data in hardware, it
      might still make sense to implement software double buffering to avoid
      losing data while the user is reading data out. For this purpose, add
      a pmu capability that guarantees multiple high-order chunks for AUX buffer,
      so that the pmu driver can do switchover tricks.
      
      To make use of this feature, add PERF_PMU_CAP_AUX_SW_DOUBLEBUF to your
      pmu's capability mask. This will make the ring buffer AUX allocation code
      ensure that the biggest high order allocation for the aux buffer pages is
      no bigger than half of the total requested buffer size, thus making sure
      that the buffer has at least two high order allocations.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-5-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      6a279230
    • A
      perf: Support high-order allocations for AUX space · 0a4e38e6
      Alexander Shishkin 提交于
      Some pmus (such as BTS or Intel PT without multiple-entry ToPA capability)
      don't support scatter-gather and will prefer larger contiguous areas for
      their output regions.
      
      This patch adds a new pmu capability to request higher order allocations.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-4-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      0a4e38e6
    • P
      perf: Add AUX area to ring buffer for raw data streams · 45bfb2e5
      Peter Zijlstra 提交于
      This patch introduces "AUX space" in the perf mmap buffer, intended for
      exporting high bandwidth data streams to userspace, such as instruction
      flow traces.
      
      AUX space is a ring buffer, defined by aux_{offset,size} fields in the
      user_page structure, and read/write pointers aux_{head,tail}, which abide
      by the same rules as data_* counterparts of the main perf buffer.
      
      In order to allocate/mmap AUX, userspace needs to set up aux_offset to
      such an offset that will be greater than data_offset+data_size and
      aux_size to be the desired buffer size. Both need to be page aligned.
      Then, same aux_offset and aux_size should be passed to mmap() call and
      if everything adds up, you should have an AUX buffer as a result.
      
      Pages that are mapped into this buffer also come out of user's mlock
      rlimit plus perf_event_mlock_kb allowance.
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-3-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      45bfb2e5
    • A
      perf: Add data_{offset,size} to user_page · e8c6deac
      Alexander Shishkin 提交于
      Currently, the actual perf ring buffer is one page into the mmap area,
      following the user page and the userspace follows this convention. This
      patch adds data_{offset,size} fields to user_page that can be used by
      userspace instead for locating perf data in the mmap area. This is also
      helpful when mapping existing or shared buffers if their size is not
      known in advance.
      
      Right now, it is made to follow the existing convention that
      
      	data_offset == PAGE_SIZE and
      	data_offset + data_size == mmap_size.
      Signed-off-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
      Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Kaixu Xia <kaixu.xia@linaro.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: acme@infradead.org
      Cc: adrian.hunter@intel.com
      Cc: kan.liang@intel.com
      Cc: markus.t.metzger@intel.com
      Cc: mathieu.poirier@linaro.org
      Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e8c6deac
    • A
      tracing: Allow BPF programs to call bpf_trace_printk() · 9c959c86
      Alexei Starovoitov 提交于
      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: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NSteven 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: NIngo Molnar <mingo@kernel.org>
      9c959c86
    • A
      tracing: Allow BPF programs to call bpf_ktime_get_ns() · d9847d31
      Alexei Starovoitov 提交于
      bpf_ktime_get_ns() is used by programs to compute time delta
      between events or as a timestamp
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NSteven 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/1427312966-8434-5-git-send-email-ast@plumgrid.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      d9847d31
    • A
      tracing, perf: Implement BPF programs attached to kprobes · 2541517c
      Alexei Starovoitov 提交于
      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: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
      Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.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: 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/1427312966-8434-4-git-send-email-ast@plumgrid.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      2541517c
    • A
      tracing: Add kprobe flag · 72cbbc89
      Alexei Starovoitov 提交于
      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: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
      Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.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: 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/1427312966-8434-3-git-send-email-ast@plumgrid.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      72cbbc89
    • D
      bpf: Make internal bpf API independent of CONFIG_BPF_SYSCALL #ifdefs · 4e537f7f
      Daniel Borkmann 提交于
      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: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
      Reviewed-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Link: http://lkml.kernel.org/r/1427312966-8434-2-git-send-email-ast@plumgrid.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      4e537f7f
  2. 27 3月, 2015 5 次提交
  3. 26 3月, 2015 1 次提交
    • M
      mm: numa: slow PTE scan rate if migration failures occur · 074c2381
      Mel Gorman 提交于
      Dave Chinner reported the following on https://lkml.org/lkml/2015/3/1/226
      
        Across the board the 4.0-rc1 numbers are much slower, and the degradation
        is far worse when using the large memory footprint configs. Perf points
        straight at the cause - this is from 4.0-rc1 on the "-o bhash=101073" config:
      
         -   56.07%    56.07%  [kernel]            [k] default_send_IPI_mask_sequence_phys
            - default_send_IPI_mask_sequence_phys
               - 99.99% physflat_send_IPI_mask
                  - 99.37% native_send_call_func_ipi
                       smp_call_function_many
                     - native_flush_tlb_others
                        - 99.85% flush_tlb_page
                             ptep_clear_flush
                             try_to_unmap_one
                             rmap_walk
                             try_to_unmap
                             migrate_pages
                             migrate_misplaced_page
                           - handle_mm_fault
                              - 99.73% __do_page_fault
                                   trace_do_page_fault
                                   do_async_page_fault
                                 + async_page_fault
                    0.63% native_send_call_func_single_ipi
                       generic_exec_single
                       smp_call_function_single
      
      This is showing excessive migration activity even though excessive
      migrations are meant to get throttled.  Normally, the scan rate is tuned
      on a per-task basis depending on the locality of faults.  However, if
      migrations fail for any reason then the PTE scanner may scan faster if
      the faults continue to be remote.  This means there is higher system CPU
      overhead and fault trapping at exactly the time we know that migrations
      cannot happen.  This patch tracks when migration failures occur and
      slows the PTE scanner.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Reported-by: NDave Chinner <david@fromorbit.com>
      Tested-by: NDave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      074c2381
  4. 23 3月, 2015 1 次提交
  5. 20 3月, 2015 3 次提交
    • C
      target: do not reject FUA CDBs when write cache is enabled but emulate_write_cache is 0 · 9bc6548f
      Christophe Vu-Brugier 提交于
      A check that rejects a CDB with FUA bit set if no write cache is
      emulated was added by the following commit:
      
        fde9f50f target: Add sanity checks for DPO/FUA bit usage
      
      The condition is as follows:
      
        if (!dev->dev_attrib.emulate_fua_write ||
            !dev->dev_attrib.emulate_write_cache)
      
      However, this check is wrong if the backend device supports WCE but
      "emulate_write_cache" is disabled.
      
      This patch uses se_dev_check_wce() (previously named
      spc_check_dev_wce) to invoke transport->get_write_cache() if the
      device has a write cache or check the "emulate_write_cache" attribute
      otherwise.
      Reported-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NChristophe Vu-Brugier <cvubrugier@fastmail.fm>
      Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>
      9bc6548f
    • P
      regmap: introduce regmap_name to fix syscon regmap trace events · c6b570d9
      Philipp Zabel 提交于
      This patch fixes a NULL pointer dereference when enabling regmap event
      tracing in the presence of a syscon regmap, introduced by commit bdb0066d
      ("mfd: syscon: Decouple syscon interface from platform devices").
      That patch introduced syscon regmaps that have their dev field set to NULL.
      The regmap trace events expect it to point to a valid struct device and feed
      it to dev_name():
      
        $ echo 1 > /sys/kernel/debug/tracing/events/regmap/enable
      
        Unable to handle kernel NULL pointer dereference at virtual address 0000002c
        pgd = 80004000
        [0000002c] *pgd=00000000
        Internal error: Oops: 17 [#1] SMP ARM
        Modules linked in: coda videobuf2_vmalloc
        CPU: 0 PID: 304 Comm: kworker/0:2 Not tainted 4.0.0-rc2+ #9197
        Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
        Workqueue: events_freezable thermal_zone_device_check
        task: 9f25a200 ti: 9f1ee000 task.ti: 9f1ee000
        PC is at ftrace_raw_event_regmap_block+0x3c/0xe4
        LR is at _regmap_raw_read+0x1bc/0x1cc
        pc : [<803636e8>]    lr : [<80365f2c>]    psr: 600f0093
        sp : 9f1efd78  ip : 9f1efdb8  fp : 9f1efdb4
        r10: 00000004  r9 : 00000001  r8 : 00000001
        r7 : 00000180  r6 : 00000000  r5 : 9f00e3c0  r4 : 00000003
        r3 : 00000001  r2 : 00000180  r1 : 00000000  r0 : 9f00e3c0
        Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
        Control: 10c5387d  Table: 2d91004a  DAC: 00000015
        Process kworker/0:2 (pid: 304, stack limit = 0x9f1ee210)
        Stack: (0x9f1efd78 to 0x9f1f0000)
        fd60:                                                       9f1efda4 9f1efd88
        fd80: 800708c0 805f9510 80927140 800f0013 9f1fc800 9eb2f490 00000000 00000180
        fda0: 808e3840 00000001 9f1efdfc 9f1efdb8 80365f2c 803636b8 805f8958 800708e0
        fdc0: a00f0013 803636ac 9f16de00 00000180 80927140 9f1fc800 9f1fc800 9f1efe6c
        fde0: 9f1efe6c 9f732400 00000000 00000000 9f1efe1c 9f1efe00 80365f70 80365d7c
        fe00: 80365f3c 9f1fc800 9f1fc800 00000180 9f1efe44 9f1efe20 803656a4 80365f48
        fe20: 9f1fc800 00000180 9f1efe6c 9f1efe6c 9f732400 00000000 9f1efe64 9f1efe48
        fe40: 803657bc 80365634 00000001 9e95f910 9f1fc800 9f1efeb4 9f1efe8c 9f1efe68
        fe60: 80452ac0 80365778 9f1efe8c 9f1efe78 9e93d400 9e93d5e8 9f1efeb4 9f72ef40
        fe80: 9f1efeac 9f1efe90 8044e11c 80452998 8045298c 9e93d608 9e93d400 808e1978
        fea0: 9f1efecc 9f1efeb0 8044fd14 8044e0d0 ffffffff 9f25a200 9e93d608 9e481380
        fec0: 9f1efedc 9f1efed0 8044fde8 8044fcec 9f1eff1c 9f1efee0 80038d50 8044fdd8
        fee0: 9f1ee020 9f72ef40 9e481398 00000000 00000008 9f72ef54 9f1ee020 9f72ef40
        ff00: 9e481398 9e481380 00000008 9f72ef40 9f1eff5c 9f1eff20 80039754 80038bfc
        ff20: 00000000 9e481380 80894100 808e1662 00000000 9e4f2ec0 00000000 9e481380
        ff40: 800396f8 00000000 00000000 00000000 9f1effac 9f1eff60 8003e020 80039704
        ff60: ffffffff 00000000 ffffffff 9e481380 00000000 00000000 9f1eff78 9f1eff78
        ff80: 00000000 00000000 9f1eff88 9f1eff88 9e4f2ec0 8003df30 00000000 00000000
        ffa0: 00000000 9f1effb0 8000eb60 8003df3c 00000000 00000000 00000000 00000000
        ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
        ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
        Backtrace:
        [<803636ac>] (ftrace_raw_event_regmap_block) from [<80365f2c>] (_regmap_raw_read+0x1bc/0x1cc)
         r9:00000001 r8:808e3840 r7:00000180 r6:00000000 r5:9eb2f490 r4:9f1fc800
        [<80365d70>] (_regmap_raw_read) from [<80365f70>] (_regmap_bus_read+0x34/0x6c)
         r10:00000000 r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:9f1fc800
         r4:9f1fc800
        [<80365f3c>] (_regmap_bus_read) from [<803656a4>] (_regmap_read+0x7c/0x144)
         r6:00000180 r5:9f1fc800 r4:9f1fc800 r3:80365f3c
        [<80365628>] (_regmap_read) from [<803657bc>] (regmap_read+0x50/0x70)
         r9:00000000 r8:9f732400 r7:9f1efe6c r6:9f1efe6c r5:00000180 r4:9f1fc800
        [<8036576c>] (regmap_read) from [<80452ac0>] (imx_get_temp+0x134/0x1a4)
         r6:9f1efeb4 r5:9f1fc800 r4:9e95f910 r3:00000001
        [<8045298c>] (imx_get_temp) from [<8044e11c>] (thermal_zone_get_temp+0x58/0x74)
         r7:9f72ef40 r6:9f1efeb4 r5:9e93d5e8 r4:9e93d400
        [<8044e0c4>] (thermal_zone_get_temp) from [<8044fd14>] (thermal_zone_device_update+0x34/0xec)
         r6:808e1978 r5:9e93d400 r4:9e93d608 r3:8045298c
        [<8044fce0>] (thermal_zone_device_update) from [<8044fde8>] (thermal_zone_device_check+0x1c/0x20)
         r5:9e481380 r4:9e93d608
        [<8044fdcc>] (thermal_zone_device_check) from [<80038d50>] (process_one_work+0x160/0x3d4)
        [<80038bf0>] (process_one_work) from [<80039754>] (worker_thread+0x5c/0x4f4)
         r10:9f72ef40 r9:00000008 r8:9e481380 r7:9e481398 r6:9f72ef40 r5:9f1ee020
         r4:9f72ef54
        [<800396f8>] (worker_thread) from [<8003e020>] (kthread+0xf0/0x108)
         r10:00000000 r9:00000000 r8:00000000 r7:800396f8 r6:9e481380 r5:00000000
         r4:9e4f2ec0
        [<8003df30>] (kthread) from [<8000eb60>] (ret_from_fork+0x14/0x34)
         r7:00000000 r6:00000000 r5:8003df30 r4:9e4f2ec0
        Code: e3140040 1a00001a e3140020 1a000016 (e596002c)
        ---[ end trace 193c15c2494ec960 ]---
      
      Fixes: bdb0066d (mfd: syscon: Decouple syscon interface from platform devices)
      Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
      Signed-off-by: NMark Brown <broonie@kernel.org>
      Cc: stable@vger.kernel.org
      c6b570d9
    • S
      ata: Add a new flag to destinguish sas controller · 5067c046
      Shaohua Li 提交于
      SAS controller has its own tag allocation, which doesn't directly match to ATA
      tag, so SAS and SATA have different code path for ata tags. Originally we use
      port->scsi_host (98bd4be1) to destinguish SAS controller, but libsas set
      ->scsi_host too, so we can't use it for the destinguish, we add a new flag for
      this purpose.
      
      Without this patch, the following oops can happen because scsi-mq uses
      a host-wide tag map shared among all devices with some integer tag
      values >= ATA_MAX_QUEUE.  These unexpectedly high tag values cause
      __ata_qc_from_tag() to return NULL, which is then dereferenced in
      ata_qc_new_init().
      
        BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
        IP: [<ffffffff804fd46e>] ata_qc_new_init+0x3e/0x120
        PGD 32adf0067 PUD 32adf1067 PMD 0
        Oops: 0002 [#1] SMP DEBUG_PAGEALLOC
        Modules linked in: iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi igb
        i2c_algo_bit ptp pps_core pm80xx libsas scsi_transport_sas sg coretemp
        eeprom w83795 i2c_i801
        CPU: 4 PID: 1450 Comm: cydiskbench Not tainted 4.0.0-rc3 #1
        Hardware name: Supermicro X8DTH-i/6/iF/6F/X8DTH, BIOS 2.1b       05/04/12
        task: ffff8800ba86d500 ti: ffff88032a064000 task.ti: ffff88032a064000
        RIP: 0010:[<ffffffff804fd46e>]  [<ffffffff804fd46e>] ata_qc_new_init+0x3e/0x120
        RSP: 0018:ffff88032a067858  EFLAGS: 00010046
        RAX: 0000000000000000 RBX: ffff8800ba0d2230 RCX: 000000000000002a
        RDX: ffffffff80505ae0 RSI: 0000000000000020 RDI: ffff8800ba0d2230
        RBP: ffff88032a067868 R08: 0000000000000201 R09: 0000000000000001
        R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800ba0d0000
        R13: ffff8800ba0d2230 R14: ffffffff80505ae0 R15: ffff8800ba0d0000
        FS:  0000000041223950(0063) GS:ffff88033e480000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
        CR2: 0000000000000058 CR3: 000000032a0a3000 CR4: 00000000000006e0
        Stack:
         ffff880329eee758 ffff880329eee758 ffff88032a0678a8 ffffffff80502dad
         ffff8800ba167978 ffff880329eee758 ffff88032bf9c520 ffff8800ba167978
         ffff88032bf9c520 ffff88032bf9a290 ffff88032a0678b8 ffffffff80506909
        Call Trace:
         [<ffffffff80502dad>] ata_scsi_translate+0x3d/0x1b0
         [<ffffffff80506909>] ata_sas_queuecmd+0x149/0x2a0
         [<ffffffffa0046650>] sas_queuecommand+0xa0/0x1f0 [libsas]
         [<ffffffff804ea544>] scsi_dispatch_cmd+0xd4/0x1a0
         [<ffffffff804eb50f>] scsi_queue_rq+0x66f/0x7f0
         [<ffffffff803e5098>] __blk_mq_run_hw_queue+0x208/0x3f0
         [<ffffffff803e54b8>] blk_mq_run_hw_queue+0x88/0xc0
         [<ffffffff803e5c74>] blk_mq_insert_request+0xc4/0x130
         [<ffffffff803e0b63>] blk_execute_rq_nowait+0x73/0x160
         [<ffffffffa0023fca>] sg_common_write+0x3da/0x720 [sg]
         [<ffffffffa0025100>] sg_new_write+0x250/0x360 [sg]
         [<ffffffffa0025feb>] sg_write+0x13b/0x450 [sg]
         [<ffffffff8032ec91>] vfs_write+0xd1/0x1b0
         [<ffffffff8032ee54>] SyS_write+0x54/0xc0
         [<ffffffff80689932>] system_call_fastpath+0x12/0x17
      
      tj: updated description.
      
      Fixes: 12cb5ce1 ("libata: use blk taging")
      Reported-and-tested-by: NTony Battersby <tonyb@cybernetics.com>
      Signed-off-by: NShaohua Li <shli@fb.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      5067c046
  6. 19 3月, 2015 1 次提交
    • P
      netfilter: restore rule tracing via nfnetlink_log · 4017a7ee
      Pablo Neira Ayuso 提交于
      Since fab4085f ("netfilter: log: nf_log_packet() as real unified
      interface"), the loginfo structure that is passed to nf_log_packet() is
      used to explicitly indicate the logger type you want to use.
      
      This is a problem for people tracing rules through nfnetlink_log since
      packets are always routed to the NF_LOG_TYPE logger after the
      aforementioned patch.
      
      We can fix this by removing the trace loginfo structures, but that still
      changes the log level from 4 to 5 for tracing messages and there may be
      someone relying on this outthere. So let's just introduce a new
      nf_log_trace() function that restores the former behaviour.
      Reported-by: NMarkus Kötter <koetter@rrzn.uni-hannover.de>
      Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      4017a7ee
  7. 18 3月, 2015 2 次提交
  8. 17 3月, 2015 2 次提交
    • K
      regulator: palmas: Correct TPS659038 register definition for REGEN2 · e03826d5
      Keerthy 提交于
      The register offset for REGEN2_CTRL in different for TPS659038 chip as when
      compared with other Palmas family PMICs. In the case of TPS659038 the wrong
      offset pointed to PLLEN_CTRL and was causing a hang. Correcting the same.
      Signed-off-by: NKeerthy <j-keerthy@ti.com>
      Signed-off-by: NMark Brown <broonie@kernel.org>
      Cc: stable@vger.kernel.org
      e03826d5
    • P
      livepatch: Fix subtle race with coming and going modules · 8cb2c2dc
      Petr Mladek 提交于
      There is a notifier that handles live patches for coming and going modules.
      It takes klp_mutex lock to avoid races with coming and going patches but
      it does not keep the lock all the time. Therefore the following races are
      possible:
      
        1. The notifier is called sometime in STATE_MODULE_COMING. The module
           is visible by find_module() in this state all the time. It means that
           new patch can be registered and enabled even before the notifier is
           called. It might create wrong order of stacked patches, see below
           for an example.
      
         2. New patch could still see the module in the GOING state even after
            the notifier has been called. It will try to initialize the related
            object structures but the module could disappear at any time. There
            will stay mess in the structures. It might even cause an invalid
            memory access.
      
      This patch solves the problem by adding a boolean variable into struct module.
      The value is true after the coming and before the going handler is called.
      New patches need to be applied when the value is true and they need to ignore
      the module when the value is false.
      
      Note that we need to know state of all modules on the system. The races are
      related to new patches. Therefore we do not know what modules will get
      patched.
      
      Also note that we could not simply ignore going modules. The code from the
      module could be called even in the GOING state until mod->exit() finishes.
      If we start supporting patches with semantic changes between function
      calls, we need to apply new patches to any still usable code.
      See below for an example.
      
      Finally note that the patch solves only the situation when a new patch is
      registered. There are no such problems when the patch is being removed.
      It does not matter who disable the patch first, whether the normal
      disable_patch() or the module notifier. There is nothing to do
      once the patch is disabled.
      
      Alternative solutions:
      ======================
      
      + reject new patches when a patched module is coming or going; this is ugly
      
      + wait with adding new patch until the module leaves the COMING and GOING
        states; this might be dangerous and complicated; we would need to release
        kgr_lock in the middle of the patch registration to avoid a deadlock
        with the coming and going handlers; also we might need a waitqueue for
        each module which seems to be even bigger overhead than the boolean
      
      + stop modules from entering COMING and GOING states; wait until modules
        leave these states when they are already there; looks complicated; we would
        need to ignore the module that asked to stop the others to avoid a deadlock;
        also it is unclear what to do when two modules asked to stop others and
        both are in COMING state (situation when two new patches are applied)
      
      + always register/enable new patches and fix up the potential mess (registered
        patches order) in klp_module_init(); this is nasty and prone to regressions
        in the future development
      
      + add another MODULE_STATE where the kallsyms are visible but the module is not
        used yet; this looks too complex; the module states are checked on "many"
        locations
      
      Example of patch stacking breakage:
      ===================================
      
      The notifier could _not_ _simply_ ignore already initialized module objects.
      For example, let's have three patches (P1, P2, P3) for functions a() and b()
      where a() is from vmcore and b() is from a module M. Something like:
      
      	a()	b()
      P1	a1()	b1()
      P2	a2()	b2()
      P3	a3()	b3(3)
      
      If you load the module M after all patches are registered and enabled.
      The ftrace ops for function a() and b() has listed the functions in this
      order:
      
      	ops_a->func_stack -> list(a3,a2,a1)
      	ops_b->func_stack -> list(b3,b2,b1)
      
      , so the pointer to b3() is the first and will be used.
      
      Then you might have the following scenario. Let's start with state when patches
      P1 and P2 are registered and enabled but the module M is not loaded. Then ftrace
      ops for b() does not exist. Then we get into the following race:
      
      CPU0					CPU1
      
      load_module(M)
      
        complete_formation()
      
        mod->state = MODULE_STATE_COMING;
        mutex_unlock(&module_mutex);
      
      					klp_register_patch(P3);
      					klp_enable_patch(P3);
      
      					# STATE 1
      
        klp_module_notify(M)
          klp_module_notify_coming(P1);
          klp_module_notify_coming(P2);
          klp_module_notify_coming(P3);
      
      					# STATE 2
      
      The ftrace ops for a() and b() then looks:
      
        STATE1:
      
      	ops_a->func_stack -> list(a3,a2,a1);
      	ops_b->func_stack -> list(b3);
      
        STATE2:
      	ops_a->func_stack -> list(a3,a2,a1);
      	ops_b->func_stack -> list(b2,b1,b3);
      
      therefore, b2() is used for the module but a3() is used for vmcore
      because they were the last added.
      
      Example of the race with going modules:
      =======================================
      
      CPU0					CPU1
      
      delete_module()  #SYSCALL
      
         try_stop_module()
           mod->state = MODULE_STATE_GOING;
      
         mutex_unlock(&module_mutex);
      
      					klp_register_patch()
      					klp_enable_patch()
      
      					#save place to switch universe
      
      					b()     # from module that is going
      					  a()   # from core (patched)
      
         mod->exit();
      
      Note that the function b() can be called until we call mod->exit().
      
      If we do not apply patch against b() because it is in MODULE_STATE_GOING,
      it will call patched a() with modified semantic and things might get wrong.
      
      [jpoimboe@redhat.com: use one boolean instead of two]
      Signed-off-by: NPetr Mladek <pmladek@suse.cz>
      Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      8cb2c2dc
  9. 14 3月, 2015 2 次提交
  10. 13 3月, 2015 6 次提交
  11. 12 3月, 2015 3 次提交