Skip to content

L
linux
Switch branch/tag
  1. 18 May, 2011 11 commits
    • Steven Rostedt's avatar
      ftrace: Allow dynamically allocated function tracers · cdbe61bf
      Steven Rostedt authored 
      Now that functions may be selected individually, it only makes sense
that we should allow dynamically allocated trace structures to
be traced. This will allow perf to allocate a ftrace_ops structure
at runtime and use it to pick and choose which functions that
structure will trace.

Note, a dynamically allocated ftrace_ops will always be called
indirectly instead of being called directly from the mcount in
entry.S. This is because there's no safe way to prevent mcount
from being preempted before calling the function, unless we
modify every entry.S to do so (not likely). Thus, dynamically allocated
functions will now be called by the ftrace_ops_list_func() that
loops through the ops that are allocated if there are more than
one op allocated at a time. This loop is protected with a
preempt_disable.

To determine if an ftrace_ops structure is allocated or not, a new
util function was added to the kernel/extable.c called
core_kernel_data(), which returns 1 if the address is between
_sdata and _edata.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      cdbe61bf
    • Steven Rostedt's avatar
      ftrace: Implement separate user function filtering · b848914c
      Steven Rostedt authored 
      ftrace_ops that are registered to trace functions can now be
agnostic to each other in respect to what functions they trace.
Each ops has their own hash of the functions they want to trace
and a hash to what they do not want to trace. A empty hash for
the functions they want to trace denotes all functions should
be traced that are not in the notrace hash.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      b848914c
    • Steven Rostedt's avatar
      ftrace: Free hash with call_rcu_sched() · 07fd5515
      Steven Rostedt authored 
      When a hash is modified and might be in use, we need to perform
a schedule RCU operation on it, as the hashes will soon be used
directly in the function tracer callback.

Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      07fd5515
    • Steven Rostedt's avatar
      ftrace: Have global_ops store the functions that are to be traced · 2b499381
      Steven Rostedt authored 
      This is a step towards each ops structure defining its own set
of functions to trace. As the current code with pid's and such
are specific to the global_ops, it is restructured to be used
with the global ops.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      2b499381
    • Steven Rostedt's avatar
      ftrace: Add ops parameter to ftrace_startup/shutdown functions · bd69c30b
      Steven Rostedt authored 
      In order to allow different ops to enable different functions,
the ftrace_startup() and ftrace_shutdown() functions need the
ops parameter passed to them.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      bd69c30b
    • Steven Rostedt's avatar
      ftrace: Add enabled_functions file · 647bcd03
      Steven Rostedt authored 
      Add the enabled_functions file that is used to show all the
functions that have been enabled for tracing as well as their
ref counts. This helps seeing if any function has been registered
and what functions are being traced.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      647bcd03
    • Steven Rostedt's avatar
      ftrace: Use counters to enable functions to trace · ed926f9b
      Steven Rostedt authored 
      Every function has its own record that stores the instruction
pointer and flags for the function to be traced. There are only
two flags: enabled and free. The enabled flag states that tracing
for the function has been enabled (actively traced), and the free
flag states that the record no longer points to a function and can
be used by new functions (loaded modules).

These flags are now moved to the MSB of the flags (actually just
the top 32bits). The rest of the bits (30 bits) are now used as
a ref counter. Everytime a tracer register functions to trace,
those functions will have its counter incremented.

When tracing is enabled, to determine if a function should be traced,
the counter is examined, and if it is non-zero it is set to trace.

When a ftrace_ops is registered to trace functions, its hashes
are examined. If the ftrace_ops filter_hash count is zero, then
all functions are set to be traced, otherwise only the functions
in the hash are to be traced. The exception to this is if a function
is also in the ftrace_ops notrace_hash. Then that function's counter
is not incremented for this ftrace_ops.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      ed926f9b
    • Steven Rostedt's avatar
      ftrace: Separate hash allocation and assignment · 33dc9b12
      Steven Rostedt authored 
      When filtering, allocate a hash to insert the function records.
After the filtering is complete, assign it to the ftrace_ops structure.

This allows the ftrace_ops structure to have a much smaller array of
hash buckets instead of wasting a lot of memory.

A read only empty_hash is created to be the minimum size that any ftrace_ops
can point to.

When a new hash is created, it has the following steps:

o Allocate a default hash.
o Walk the function records assigning the filtered records to the hash
o Allocate a new hash with the appropriate size buckets
o Move the entries from the default hash to the new hash.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      33dc9b12
    • Steven Rostedt's avatar
      ftrace: Create a global_ops to hold the filter and notrace hashes · f45948e8
      Steven Rostedt authored 
      Combine the filter and notrace hashes to be accessed by a single entity,
the global_ops. The global_ops is a ftrace_ops structure that is passed
to different functions that can read or modify the filtering of the
function tracer.

The ftrace_ops structure was modified to hold a filter and notrace
hashes so that later patches may allow each ftrace_ops to have its own
set of rules to what functions may be filtered.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      f45948e8
    • Steven Rostedt's avatar
      ftrace: Use hash instead for FTRACE_FL_FILTER · 1cf41dd7
      Steven Rostedt authored 
      When multiple users are allowed to have their own set of functions
to trace, having the FTRACE_FL_FILTER flag will not be enough to
handle the accounting of those users. Each user will need their own
set of functions.

Replace the FTRACE_FL_FILTER with a filter_hash instead. This is
temporary until the rest of the function filtering accounting
gets in.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      1cf41dd7
    • Steven Rostedt's avatar
      ftrace: Replace FTRACE_FL_NOTRACE flag with a hash of ignored functions · b448c4e3
      Steven Rostedt authored 
      To prepare for the accounting system that will allow multiple users of
the function tracer, having the FTRACE_FL_NOTRACE as a flag in the
dyn_trace record does not make sense.

All ftrace_ops will soon have a hash of functions they should trace
and not trace. By making a global hash of functions not to trace makes
this easier for the transition.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      b448c4e3
  3. 17 May, 2011 1 commit
    • Stephane Eranian's avatar
      perf: Fix multi-event parsing bug · 94692349
      Stephane Eranian authored 
      This patch fixes an issue with event parsing.
The following commit appears to have broken the
ability to specify a comma separated list of events:

   commit ceb53fbf
   Author: Ingo Molnar <mingo@elte.hu>
   Date:   Wed Apr 27 04:06:33 2011 +0200

       perf stat: Fail more clearly when an invalid modifier is specified

This patch fixes this while preserving the desired effect:

$ perf stat -e instructions:u,instructions:k ls /dev/null /dev/null

 Performance counter stats for 'ls /dev/null':

            365956 instructions:u           #    0.00  insns per cycle
            731806 instructions:k           #    0.00  insns per cycle

        0.001108862  seconds time elapsed

$ perf stat -e task-clock-msecs true
invalid event modifier: '-msecs'
Run 'perf list' for a list of valid events and modifiers
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Cc: acme@redhat.com
Cc: peterz@infradead.org
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/20110517133619.GA6999@quadSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
      94692349
  5. 12 May, 2011 1 commit
  7. 10 May, 2011 4 commits
  9. 09 May, 2011 23 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7