1. 10 11月, 2009 1 次提交
    • P
      ksym_tracer: Support read accesses independent of read/write. · 676c0dbe
      Paul Mundt 提交于
      All of the infrastructure already exists to support read accesses
      for platforms that support a read access independently of read/write
      (such as in the case of the SuperH UBC). This just trivially hooks
      up the read case by itself.
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Prasad <prasad@linux.vnet.ibm.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Jan Kiszka <jan.kiszka@web.de>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Masami Hiramatsu <mhiramat@redhat.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      LKML-Reference: <20091109083733.GA25848@linux-sh.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      676c0dbe
  2. 08 11月, 2009 3 次提交
    • L
      ksym_tracer: Remove KSYM_SELFTEST_ENTRY · 30ff21e3
      Li Zefan 提交于
      The macro used to be used in both trace_selftest.c and
      trace_ksym.c, but no longer, so remove it from header file.
      Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Prasad <prasad@linux.vnet.ibm.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      30ff21e3
    • F
      hw-breakpoints: Arbitrate access to pmu following registers constraints · ba1c813a
      Frederic Weisbecker 提交于
      Allow or refuse to build a counter using the breakpoints pmu following
      given constraints.
      
      We keep track of the pmu users by using three per cpu variables:
      
      - nr_cpu_bp_pinned stores the number of pinned cpu breakpoints counters
        in the given cpu
      
      - nr_bp_flexible stores the number of non-pinned breakpoints counters
        in the given cpu.
      
      - task_bp_pinned stores the number of pinned task breakpoints in a cpu
      
      The latter is not a simple counter but gathers the number of tasks that
      have n pinned breakpoints.
      Considering HBP_NUM the number of available breakpoint address
      registers:
         task_bp_pinned[0] is the number of tasks having 1 breakpoint
         task_bp_pinned[1] is the number of tasks having 2 breakpoints
         [...]
         task_bp_pinned[HBP_NUM - 1] is the number of tasks having the
         maximum number of registers (HBP_NUM).
      
      When a breakpoint counter is created and wants an access to the pmu,
      we evaluate the following constraints:
      
      == Non-pinned counter ==
      
      - If attached to a single cpu, check:
      
          (per_cpu(nr_bp_flexible, cpu) || (per_cpu(nr_cpu_bp_pinned, cpu)
               + max(per_cpu(task_bp_pinned, cpu)))) < HBP_NUM
      
             -> If there are already non-pinned counters in this cpu, it
                means there is already a free slot for them.
                Otherwise, we check that the maximum number of per task
                breakpoints (for this cpu) plus the number of per cpu
                breakpoint (for this cpu) doesn't cover every registers.
      
      - If attached to every cpus, check:
      
          (per_cpu(nr_bp_flexible, *) || (max(per_cpu(nr_cpu_bp_pinned, *))
                 + max(per_cpu(task_bp_pinned, *)))) < HBP_NUM
      
             -> This is roughly the same, except we check the number of per
                cpu bp for every cpu and we keep the max one. Same for the
                per tasks breakpoints.
      
      == Pinned counter ==
      
      - If attached to a single cpu, check:
      
             ((per_cpu(nr_bp_flexible, cpu) > 1)
                  + per_cpu(nr_cpu_bp_pinned, cpu)
                  + max(per_cpu(task_bp_pinned, cpu))) < HBP_NUM
      
             -> Same checks as before. But now the nr_bp_flexible, if any,
                must keep one register at least (or flexible breakpoints will
                never be be fed).
      
      - If attached to every cpus, check:
      
            ((per_cpu(nr_bp_flexible, *) > 1)
                 + max(per_cpu(nr_cpu_bp_pinned, *))
                 + max(per_cpu(task_bp_pinned, *))) < HBP_NUM
      
      Changes in v2:
      
      - Counter -> event rename
      
      Changes in v5:
      
      - Fix unreleased non-pinned task-bound-only counters. We only released
        it in the first cpu. (Thanks to Paul Mackerras for reporting that)
      
      Changes in v6:
      
      - Currently, events scheduling are done in this order: cpu context
        pinned + cpu context non-pinned + task context pinned + task context
        non-pinned events. Then our current constraints are right theoretically
        but not in practice, because non-pinned counters may be scheduled
        before we can apply every possible pinned counters. So consider
        non-pinned counters as pinned for now.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Prasad <prasad@linux.vnet.ibm.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jan Kiszka <jan.kiszka@web.de>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Masami Hiramatsu <mhiramat@redhat.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      ba1c813a
    • F
      hw-breakpoints: Rewrite the hw-breakpoints layer on top of perf events · 24f1e32c
      Frederic Weisbecker 提交于
      This patch rebase the implementation of the breakpoints API on top of
      perf events instances.
      
      Each breakpoints are now perf events that handle the
      register scheduling, thread/cpu attachment, etc..
      
      The new layering is now made as follows:
      
             ptrace       kgdb      ftrace   perf syscall
                \          |          /         /
                 \         |         /         /
                                              /
                  Core breakpoint API        /
                                            /
                           |               /
                           |              /
      
                    Breakpoints perf events
      
                           |
                           |
      
                     Breakpoints PMU ---- Debug Register constraints handling
                                          (Part of core breakpoint API)
                           |
                           |
      
                   Hardware debug registers
      
      Reasons of this rewrite:
      
      - Use the centralized/optimized pmu registers scheduling,
        implying an easier arch integration
      - More powerful register handling: perf attributes (pinned/flexible
        events, exclusive/non-exclusive, tunable period, etc...)
      
      Impact:
      
      - New perf ABI: the hardware breakpoints counters
      - Ptrace breakpoints setting remains tricky and still needs some per
        thread breakpoints references.
      
      Todo (in the order):
      
      - Support breakpoints perf counter events for perf tools (ie: implement
        perf_bpcounter_event())
      - Support from perf tools
      
      Changes in v2:
      
      - Follow the perf "event " rename
      - The ptrace regression have been fixed (ptrace breakpoint perf events
        weren't released when a task ended)
      - Drop the struct hw_breakpoint and store generic fields in
        perf_event_attr.
      - Separate core and arch specific headers, drop
        asm-generic/hw_breakpoint.h and create linux/hw_breakpoint.h
      - Use new generic len/type for breakpoint
      - Handle off case: when breakpoints api is not supported by an arch
      
      Changes in v3:
      
      - Fix broken CONFIG_KVM, we need to propagate the breakpoint api
        changes to kvm when we exit the guest and restore the bp registers
        to the host.
      
      Changes in v4:
      
      - Drop the hw_breakpoint_restore() stub as it is only used by KVM
      - EXPORT_SYMBOL_GPL hw_breakpoint_restore() as KVM can be built as a
        module
      - Restore the breakpoints unconditionally on kvm guest exit:
        TIF_DEBUG_THREAD doesn't anymore cover every cases of running
        breakpoints and vcpu->arch.switch_db_regs might not always be
        set when the guest used debug registers.
        (Waiting for a reliable optimization)
      
      Changes in v5:
      
      - Split-up the asm-generic/hw-breakpoint.h moving to
        linux/hw_breakpoint.h into a separate patch
      - Optimize the breakpoints restoring while switching from kvm guest
        to host. We only want to restore the state if we have active
        breakpoints to the host, otherwise we don't care about messed-up
        address registers.
      - Add asm/hw_breakpoint.h to Kbuild
      - Fix bad breakpoint type in trace_selftest.c
      
      Changes in v6:
      
      - Fix wrong header inclusion in trace.h (triggered a build
        error with CONFIG_FTRACE_SELFTEST
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Prasad <prasad@linux.vnet.ibm.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jan Kiszka <jan.kiszka@web.de>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Masami Hiramatsu <mhiramat@redhat.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      24f1e32c
  3. 06 11月, 2009 1 次提交
  4. 04 11月, 2009 3 次提交
    • F
      perf/core: Add a callback to perf events · 97eaf530
      Frederic Weisbecker 提交于
      A simple callback in a perf event can be used for multiple purposes.
      For example it is useful for triggered based events like hardware
      breakpoints that need a callback to dispatch a triggered breakpoint
      event.
      
      v2: Simplify a bit the callback attribution as suggested by Paul
          Mackerras
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mundt <lethal@linux-sh.org>
      97eaf530
    • P
      x86/hw-breakpoints: Actually flush thread breakpoints in flush_thread(). · 41a48d14
      Paul Mundt 提交于
      flush_thread() tries to do a TIF_DEBUG check before calling in to
      flush_thread_hw_breakpoint() (which subsequently clears the thread flag),
      but for some reason, the x86 code is manually clearing TIF_DEBUG
      immediately before the test, so this path will never be taken.
      
      This kills off the erroneous clear_tsk_thread_flag() and lets
      flush_thread_hw_breakpoint() actually get invoked.
      
      Presumably folks were getting lucky with testing and the
      free_thread_info() -> free_thread_xstate() path was taking care of the
      flush there.
      Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
      Acked-by: N"K.Prasad" <prasad@linux.vnet.ibm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      LKML-Reference: <20091005102306.GA7889@linux-sh.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      41a48d14
    • A
      perf/core: Provide a kernel-internal interface to get to performance counters · fb0459d7
      Arjan van de Ven 提交于
      There are reasons for kernel code to ask for, and use, performance
      counters.
      For example, in CPU freq governors this tends to be a good idea, but
      there are other examples possible as well of course.
      
      This patch adds the needed bits to do enable this functionality; they
      have been tested in an experimental cpufreq driver that I'm working on,
      and the changes are all that I needed to access counters properly.
      
      [fweisbec@gmail.com: added pid to perf_event_create_kernel_counter so
      that we can profile a particular task too
      
      TODO: Have a better error reporting, don't just return NULL in fail
      case.]
      
      v2: Remove the wrong comment about the fact
          perf_event_create_kernel_counter must be called from a kernel
          thread.
      Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: "K.Prasad" <prasad@linux.vnet.ibm.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jan Kiszka <jan.kiszka@siemens.com>
      Cc: Jiri Slaby <jirislaby@gmail.com>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Masami Hiramatsu <mhiramat@redhat.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Jan Kiszka <jan.kiszka@web.de>
      Cc: Avi Kivity <avi@redhat.com>
      LKML-Reference: <20090925122556.2f8bd939@infradead.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      fb0459d7
  5. 18 10月, 2009 1 次提交
    • F
      Merge commit 'perf/core' into perf/hw-breakpoint · 0f8f86c7
      Frederic Weisbecker 提交于
      Conflicts:
      	kernel/Makefile
      	kernel/trace/Makefile
      	kernel/trace/trace.h
      	samples/Makefile
      
      Merge reason: We need to be uptodate with the perf events development
      branch because we plan to rewrite the breakpoints API on top of
      perf events.
      0f8f86c7
  6. 17 10月, 2009 1 次提交
  7. 15 10月, 2009 30 次提交