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This function is to search all global variables in the CU. We want to
have the list of global variables at once and match them later.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240502060011.1838090-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The die_find_func_rettype() is to find a debug entry for the given
function name and sets the type information of the return value. By
convention, it'd return the pointer to the type die (should be the
same as the given mem_die argument) if found, or NULL otherwise.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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We want to track type states as instructions are executed. Each
instruction can access compound types like struct or union and load/
store its members to a different location.
The die_deref_ptr_type() is to find a type of memory access with a
pointer variable. If it points to a compound type like struct, the
target memory is a member in the struct. The access will happen with an
offset indicating which member it refers. Let's follow the DWARF info
to figure out the type of the pointer target.
For example, say we have the following code.
struct foo {
int a;
int b;
};
struct foo *p = malloc(sizeof(*p));
p->b = 0;
The last pointer access should produce x86 asm like below:
mov 0x0, 4(%rbx)
And we know %rbx register has a pointer to struct foo. Then offset 4
should return the debug info of member 'b'.
Also variables of compound types can be accessed directly without a
pointer. The die_get_member_type() is to handle a such case.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-4-namhyung@kernel.org
[ Check if die_get_real_type() returned NULL ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The die_collect_vars() is to find all variable information in the scope
including function parameters. The struct die_var_type is to save the
type of the variable with the location (reg and offset) as well as where
it's defined in the code (addr).
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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It's not used, let's get rid of it.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20240319055115.4063940-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Local variables are allocated in the stack and the location list
should look like base register(s) and an offset. Extend the
die_find_variable_by_reg() to handle the following expressions
* DW_OP_breg{0..31}
* DW_OP_bregx
* DW_OP_fbreg
Ususally DWARF subprogram entries have frame base information and
use it to locate stack variable like below:
<2><43d1575>: Abbrev Number: 62 (DW_TAG_variable)
<43d1576> DW_AT_location : 2 byte block: 91 7c (DW_OP_fbreg: -4) <--- here
<43d1579> DW_AT_name : (indirect string, offset: 0x2c00c9): i
<43d157d> DW_AT_decl_file : 1
<43d157e> DW_AT_decl_line : 78
<43d157f> DW_AT_type : <0x43d19d7>
I found some differences on saving the frame base between gcc and clang.
The gcc uses the CFA to get the base so it needs to check the current
frame's CFI info. In this case, stack offset needs to be adjusted from
the start of the CFA.
<1><1bb8d>: Abbrev Number: 102 (DW_TAG_subprogram)
<1bb8e> DW_AT_name : (indirect string, offset: 0x74d41): kernel_init
<1bb92> DW_AT_decl_file : 2
<1bb92> DW_AT_decl_line : 1440
<1bb94> DW_AT_decl_column : 18
<1bb95> DW_AT_prototyped : 1
<1bb95> DW_AT_type : <0xcc>
<1bb99> DW_AT_low_pc : 0xffffffff81bab9e0
<1bba1> DW_AT_high_pc : 0x1b2
<1bba9> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa) <------ here
<1bbab> DW_AT_call_all_calls: 1
<1bbab> DW_AT_sibling : <0x1bf5a>
While clang sets it to a register directly and it can check the register
and offset in the instruction directly.
<1><43d1542>: Abbrev Number: 60 (DW_TAG_subprogram)
<43d1543> DW_AT_low_pc : 0xffffffff816a7c60
<43d154b> DW_AT_high_pc : 0x98
<43d154f> DW_AT_frame_base : 1 byte block: 56 (DW_OP_reg6 (rbp)) <---------- here
<43d1551> DW_AT_GNU_all_call_sites: 1
<43d1551> DW_AT_name : (indirect string, offset: 0x3bce91): foo
<43d1555> DW_AT_decl_file : 1
<43d1556> DW_AT_decl_line : 75
<43d1557> DW_AT_prototyped : 1
<43d1557> DW_AT_type : <0x43c7332>
<43d155b> DW_AT_external : 1
Also it needs to update the offset after finding the type like global
variables since the offset was from the frame base. Factor out
match_var_offset() to check global and local variables in the same way.
The type stats are improved too:
Annotate data type stats:
total 294, ok 160 (54.4%), bad 134 (45.6%)
-----------------------------------------------------------
30 : no_sym
32 : no_mem_ops
51 : no_var
14 : no_typeinfo
7 : bad_offset
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-9-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The die_get_cfa() is to get frame base register and offset at the given
instruction address (pc). This info will be used to locate stack
variables which have location expression using DW_OP_fbreg.
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240117062657.985479-8-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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The die_get_typename_from_type() is to get the name of the given DIE in
C-style type name.
The difference from die_get_typename() is that it does not retrieve the
DW_AT_type and use the given DIE directly. This will be used when users
know the type DIE already.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231213001323.718046-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The die_find_variable_by_addr() is to find a variables in the given DIE
using given (PC-relative) address. Global variables will have a
location expression with DW_OP_addr which has an address so can simply
compare it with the address.
<1><143a7>: Abbrev Number: 2 (DW_TAG_variable)
<143a8> DW_AT_name : loops_per_jiffy
<143ac> DW_AT_type : <0x1cca>
<143b0> DW_AT_external : 1
<143b0> DW_AT_decl_file : 193
<143b1> DW_AT_decl_line : 213
<143b2> DW_AT_location : 9 byte block: 3 b0 46 41 82 ff ff ff ff
(DW_OP_addr: ffffffff824146b0)
Note that the type-offset should be calculated from the base address of
the global variable.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231110000012.3538610-33-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The die_find_variable_by_reg() will search for a variable or a parameter
sub-DIE in the given scope DIE where the location matches to the given
register.
For the simplest and most common case, memory access usually happens
with a base register and an offset to the field so the register holds a
pointer in a variable or function parameter. Then we can find one if it
has a location expression at the (instruction) address. This function
only handles such a simple case for now.
In this case, the expression has a DW_OP_regN operation where N < 32.
If the register index (N) is greater than or equal to 32, DW_OP_regx
operation with an operand which saves the value for the N would be used.
It rejects expressions with more operations.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231110000012.3538610-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The die_get_scopes() returns the number of enclosing DIEs for the given
address and it fills an array of DIEs like dwarf_getscopes(). But it
doesn't follow the abstract origin of inlined functions as we want
information of the concrete instance. This is needed to check the
location of parameters and local variables properly. Users can check
the origin separately if needed.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231110000012.3538610-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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It's a usual convention that the conditional code is handled in a header
file. As I'm planning to add some more of them, let's move the current
code to the header first.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: linux-toolchains@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Link: https://lore.kernel.org/r/20231110000012.3538610-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix to get the declared file name even if it uses file index 0
in DWARF5, using custom die_get_decl_file() function.
Actually, the DWARF5 standard says file index 0 of the DW_AT_decl_file
is invalid(1), but there is a discussion and maybe this will be updated
[2].
Anyway, clang generates such DWARF5 file for the linux kernel. Thus it
must be handled.
Without this, 'perf probe' returns an error:
$ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
Debuginfo analysis failed.
Error: Failed to show lines.
With this, it can handle the case correctly:
$ ./perf probe -k $BIN_PATH/vmlinux -s $SRC_PATH -L vfs_read:10
<vfs_read@$SRC_PATH/fs/read_write.c:10>
11 ret = rw_verify_area(READ, file, pos, count);
12 if (ret)
return ret;
[1] DWARF5 specification 2.14 says "The value 0 indicates that no source file has been specified.")
[2] http://wiki.dwarfstd.org/index.php?title=DWARF5_Line_Table_File_Numbers)
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/166731052936.2100653.13380621874859467731.stgit@devnote3
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The "address" member of "struct probe_trace_point" uses long data type.
If kernel is 64-bit and perf program is 32-bit, size of "address"
variable is 32 bits.
As a result, upper 32 bits of address read from kernel are truncated, an
error occurs during address comparison in kprobe_warn_out_range().
Before:
# perf probe -a schedule
schedule is out of .text, skip it.
Error: Failed to add events.
Solution:
Change data type of "address" variable to u64 and change corresponding
address printing and value assignment.
After:
# perf.new.new probe -a schedule
Added new event:
probe:schedule (on schedule)
You can now use it in all perf tools, such as:
perf record -e probe:schedule -aR sleep 1
# perf probe -l
probe:schedule (on schedule@kernel/sched/core.c)
# perf record -e probe:schedule -aR sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.156 MB perf.data (1366 samples) ]
# perf report --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1K of event 'probe:schedule'
# Event count (approx.): 1366
#
# Overhead Command Shared Object Symbol
# ........ ............... ................. ............
#
6.22% migration/0 [kernel.kallsyms] [k] schedule
6.22% migration/1 [kernel.kallsyms] [k] schedule
6.22% migration/2 [kernel.kallsyms] [k] schedule
6.22% migration/3 [kernel.kallsyms] [k] schedule
6.15% migration/10 [kernel.kallsyms] [k] schedule
6.15% migration/11 [kernel.kallsyms] [k] schedule
6.15% migration/12 [kernel.kallsyms] [k] schedule
6.15% migration/13 [kernel.kallsyms] [k] schedule
6.15% migration/14 [kernel.kallsyms] [k] schedule
6.15% migration/15 [kernel.kallsyms] [k] schedule
6.15% migration/4 [kernel.kallsyms] [k] schedule
6.15% migration/5 [kernel.kallsyms] [k] schedule
6.15% migration/6 [kernel.kallsyms] [k] schedule
6.15% migration/7 [kernel.kallsyms] [k] schedule
6.15% migration/8 [kernel.kallsyms] [k] schedule
6.15% migration/9 [kernel.kallsyms] [k] schedule
0.22% rcu_sched [kernel.kallsyms] [k] schedule
...
#
# (Cannot load tips.txt file, please install perf!)
#
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jianlin Lv <jianlin.lv@arm.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Li Huafei <lihuafei1@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lore.kernel.org/lkml/20210715063723.11926-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix ~124 single-word typos and a few spelling errors in the perf tooling code,
accumulated over the years.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210321113734.GA248990@gmail.com
Link: http://lore.kernel.org/lkml/20210323160915.GA61903@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix die_walk_lines() to list the function entry line correctly. Since
the dwarf_entrypc() does not return the entry pc if the DIE has only
range attribute, __die_walk_funclines() fails to list the declaration
line (entry line) in that case.
To solve this issue, this introduces die_entrypc() which correctly
returns the entry PC (the first address range) even if the DIE has only
range attribute. With this fix die_walk_lines() shows the function entry
line is able to probe correctly.
Fixes: 4cc9cec636e7 ("perf probe: Introduce lines walker interface")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157190837419.1859.4619125803596816752.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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All we need there is a forward declaration for 'union perf_event', so
remove it from there and add missing header directives in places using
things from this indirect include.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-7ftk0ztstqub1tirjj8o8xbl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Match linkage name with mangled name if exists. The linkage_name is used
for storing mangled name of the object.
Thus, this allows 'perf probe' to find appropriate probe point from
mangled symbol as below.
E.g. without this fix:
----
$ perf probe -x /usr/lib64/libstdc++.so.6 \
-D _ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv
Probe point '_ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv'
not found.
Error: Failed to add events.
----
With this fix, perf probe can find the correct one.
----
$ perf probe -x /usr/lib64/libstdc++.so.6 \
-D _ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv
p:probe_libstdc/_ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv
/usr/lib64/libstdc++.so.6.0.22:0x8ca60
----
Committer notes:
After the fix, setting it for real (no -D/--definition, that amounts to
a --dry-run):
# perf probe -x /usr/lib64/libstdc++.so.6 _ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv
Added new event:
probe_libstdc:_ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv (on _ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv in /usr/lib64/libstdc++.so.6.0.22)
You can now use it in all perf tools, such as:
perf record -e probe_libstdc:_ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv -aR sleep 1
# perf probe -l probe_libstdc:*
probe_libstdc:_ZNKSt15basic_fstreamXXIwSt11char_traitsIwEE7is_openEv (on is_open@libstdc++-v3/include/fstream in /usr/lib64/libstdc++.so.6.0.22)
#
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/147464493162.29804.16715053505069382443.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Move generic dwarf related functions from util/probe-finder.c to
util/dwarf-aux.c. Functions name and their prototype are also changed
accordingly. No functionality changes.
Suggested-and-Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1472546377-25612-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Cc: Adrian Hunter <adrian.hunter@intel.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-w246stf7ponfamclsai6b9zo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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perf probe currently errors out if there are any tail calls to probed
functions:
[root@rhel71be]# perf probe do_fork
Failed to find probe point in any functions.
Error: Failed to add events.
Fix this by teaching perf to ignore tail calls.
Without patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Failed to find probe point in any functions.
An error occurred in debuginfo analysis (-2).
Error: Failed to add events. Reason: No such file or directory (Code: -2)
With patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Ignoring tail call from SyS_clone
Found 4 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
No kprobe blacklist support, ignored
Added new events:
Writing event: p:probe/do_fork _text+768432
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
[Ignore the error about failure to write event - this kernel is missing
a patch to resolve _text properly]
The reason to ignore tail calls is that the address does not belong to
any function frame. In the example above, the address in SyS_clone is
0xc0000000000bc27c, but looking at the debug-info:
<1><830081>: Abbrev Number: 133 (DW_TAG_subprogram)
<830083> DW_AT_external : 1
<830083> DW_AT_name : (indirect string, offset: 0x3cea3): SyS_clone
<830087> DW_AT_decl_file : 7
<830088> DW_AT_decl_line : 1689
<83008a> DW_AT_prototyped : 1
<83008a> DW_AT_type : <0x8110eb>
<83008e> DW_AT_low_pc : 0xc0000000000bc270
<830096> DW_AT_high_pc : 0xc
<83009e> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<8300a0> DW_AT_GNU_all_call_sites: 1
<8300a0> DW_AT_sibling : <0x830178>
<snip>
<3><830147>: Abbrev Number: 125 (DW_TAG_GNU_call_site)
<830148> DW_AT_low_pc : 0xc0000000000bc27c
<830150> DW_AT_GNU_tail_call: 1
<830150> DW_AT_abstract_origin: <0x82e7e1>
The frame ends at 0xc0000000000bc27c. I suppose this is why this
particular call is a "tail" call. FWIW, systemtap seems to ignore these
as well and requires users to explicitly place probes at these call
sites if necessary. I print out the caller so that users know.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1430394151-15928-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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It is not easy for users to get the accurate byte offset or the line
number where a local variable can be probed.
With '--range' option, local variables in the scope of the probe point
are showed with a byte offset range, and can be added according to this
range information.
For example, there are some variables in the function
generic_perform_write():
<generic_perform_write@mm/filemap.c:0>
0 ssize_t generic_perform_write(struct file *file,
1 struct iov_iter *i, loff_t pos)
2 {
3 struct address_space *mapping = file->f_mapping;
4 const struct address_space_operations *a_ops = mapping->a_ops;
...
42 status = a_ops->write_begin(file, mapping, pos, bytes, flags,
&page, &fsdata);
44 if (unlikely(status < 0))
But we fail when we try to probe the variable 'a_ops' at line 42 or 44.
$ perf probe --add 'generic_perform_write:42 a_ops'
Failed to find the location of a_ops at this address.
Perhaps, it has been optimized out.
This is because the source code do not match the assembly, so a variable
may not be available in the source code line where it appears.
After this patch, we can lookup the accurate byte offset range of a
variable, 'INV' indicates that this variable is not valid at the given
point, but available in the scope:
$ perf probe --vars 'generic_perform_write:42' --range
Available variables at generic_perform_write:42
@<generic_perform_write+141>
[INV] ssize_t written @<generic_perform_write+[324-331]>
[INV] struct address_space_operations* a_ops @<generic_perform_write+[55-61,170-176,223-246]>
[VAL] (unknown_type) fsdata @<generic_perform_write+[70-307,346-411]>
[VAL] loff_t pos @<generic_perform_write+[0-286,286-336,346-411]>
[VAL] long int status @<generic_perform_write+[83-342,346-411]>
[VAL] long unsigned int bytes @<generic_perform_write+[122-311,320-338,346-403,403-411]>
[VAL] struct address_space* mapping @<generic_perform_write+[35-344,346-411]>
[VAL] struct iov_iter* i @<generic_perform_write+[0-340,346-411]>
[VAL] struct page* page @<generic_perform_write+[70-307,346-411]>
Then it is more clear for us to add a probe with this variable:
$ perf probe --add 'generic_perform_write+170 a_ops'
Added new event:
probe:generic_perform_write (on generic_perform_write+170 with a_ops)
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Use struct strbuf instead of bare char[] to remove the length limitation
of variables in variable_list, so they will not disappear due to
overlength, and make preparation for adding more description for
variables.
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Support glob wildcards for function name when adding new probes. This
will allow us to build caches of function-entry level information with
$params.
e.g.
----
# perf probe --no-inlines --add 'kmalloc* $params'
Added new events:
probe:kmalloc_slab (on kmalloc* with $params)
probe:kmalloc_large_node (on kmalloc* with $params)
probe:kmalloc_order_trace (on kmalloc* with $params)
You can now use it in all perf tools, such as:
perf record -e probe:kmalloc_order_trace -aR sleep 1
# perf probe --list
probe:kmalloc_large_node (on kmalloc_large_node@mm/slub.c with size flags node)
probe:kmalloc_order_trace (on kmalloc_order_trace@mm/slub.c with size flags order)
probe:kmalloc_slab (on kmalloc_slab@mm/slab_common.c with size flags)
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix to handle optimized no-inline functions which have only function
definition but no actual instance at that point.
To fix this problem, we need to find actual instance of the function.
Without this patch:
----
# perf probe -a __up
Failed to get entry address of __up.
Error: Failed to add events.
# perf probe -L __up
Specified source line is not found.
Error: Failed to show lines.
----
With this patch:
----
# perf probe -a __up
Added new event:
probe:__up (on __up)
You can now use it in all perf tools, such as:
perf record -e probe:__up -aR sleep 1
# perf probe -L __up
<__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0>
0 static noinline void __sched __up(struct semaphore *sem)
{
struct semaphore_waiter *waiter = list_first_entry(&sem->wait_
struct semaphore_waite
4 list_del(&waiter->list);
5 waiter->up = true;
6 wake_up_process(waiter->task);
7 }
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150130093744.30575.43290.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix to find the correct (as much as possible) line information for
listing probes. Without this fix, perf probe --list action will show
incorrect line information as below;
probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c)
probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h)
probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h)
The minus line number is obviously wrong, and current.h is not related
to the probe point. Deeper investigation discovered that there were 2
issues related to this bug, and minor typos too.
The 1st issue is the rack of considering about nested inlined functions,
which causes the wrong (relative) line number.
The 2nd issue is that the dwarf line info is not correct at those
points. It points 14th line of current.h.
Since it seems that the line info includes somewhat unreliable
information, this fixes perf to try to find correct line information
from both of debuginfo and line info as below.
1) Probe address is the entry of a function instance
In this case, the line is set as the function declared line.
2) Probe address is the entry of an expanded inline function block
In this case, the line is set as the function call-site line.
This means that the line number is relative from the entry line
of caller function (which can be an inlined function if nested)
3) Probe address is inside a function instance or an expanded
inline function block
In this case, perf probe queries the line number from lineinfo
and verify the function declared file is same as the file name
queried from lineinfo.
If the file name is different, it is a failure case. The probe
address is shown as symbol+offset.
4) Probe address is not in the any function instance
This is a failure case, the probe address is shown as
symbol+offset.
With this fix, perf probe -l shows correct probe lines as below;
probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c)
probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c)
probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c)
Changes at v2:
- Fix typos in the function comments. (Thanks to Namhyung Kim)
- Use die_find_top_inlinefunc instead of die_find_inlinefunc_next.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The commit ba28c59bc9ed8fb7b9a753cd88ee54a2c4f6265b fixed a declaration
entry bug in probe_point_search_cb(). There are same bugs in line
finder and call_probe_finder(). This introduces a new dwarf utility
function to determine given DIE is a function definition, not
declaration.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120423032435.8737.80064.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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gcc 4.6 generates a concrete out-of-line instance when there is a
function which is implicitly inlined somewhere but also has its own
instance. The concrete out-of-line instance means that it has an
abstract origin of the function which is referred by not only
inlined-subroutines but also a concrete subprogram.
Since current dwarf_func_inline_instances() can find only instances of
inlined-subroutines, this introduces new die_walk_instances() to find
both of subprogram and inlined-subroutines.
e.g. without this,
Available variables at sched_group_rt_period
@<cpu_rt_period_read_uint+9>
struct task_group* tg
perf probe failed to find actual subprogram instance of
sched_group_rt_period().
With this,
Available variables at sched_group_rt_period
@<cpu_rt_period_read_uint+9>
struct task_group* tg
@<sched_group_rt_period+0>
struct task_group* tg
Now it found the sched_group_rt_period() itself.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Fix perf probe to search local variables in appropriate local inlined
function scope. For example, pre_schedule() has only 2 local variables,
as below;
$ perf probe -L pre_schedule
<pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0>
0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
{
2 if (prev->sched_class->pre_schedule)
3 prev->sched_class->pre_schedule(rq, prev);
}
However, current perf probe shows 4 local variables on pre_schedule(),
because it searches variables in the caller(schedule()) scope.
$ perf probe -V pre_schedule
Available variables at pre_schedule
@<schedule+445>
int cpu
long unsigned int* switch_count
struct rq* rq
struct task_struct* prev
This patch fixes this issue by searching variables in the local scope of
the instance of inlined function. Here is the result.
$ perf probe -V pre_schedule
Available variables at pre_schedule
@<schedule+445>
struct rq* rq
struct task_struct* prev
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
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Fix perf probe to walk through the lines of all nested inlined function
call sites and declared lines when a whole CU is passed to the line
walker.
The die_walk_lines() can have two different type of DIEs, subprogram (or
inlined-subroutine) DIE and CU DIE.
If a caller passes a subprogram DIE, this means that the walker walk on
lines of given subprogram. In this case, it just needs to search on
direct children of DIE tree for finding call-site information of inlined
function which directly called from given subprogram.
On the other hand, if a caller passes a CU DIE to the walker, this means
that the walker have to walk on all lines in the source files included
in given CU DIE. In this case, it has to search whole DIE trees of all
subprograms to find the call-site information of all nested inlined
functions.
Without this patch:
$ perf probe --line kernel/cpu.c:151-157
</home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151>
static int cpu_notify(unsigned long val, void *v)
{
154 return __cpu_notify(val, v, -1, NULL);
}
With this:
$ perf probe --line kernel/cpu.c:151-157
</home/mhiramat/ksrc/linux-2.6/kernel/cpu.c:151>
152 static int cpu_notify(unsigned long val, void *v)
{
154 return __cpu_notify(val, v, -1, NULL);
}
As you can see, --line option with source line range shows the declared
lines as probe-able.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110241.19900.34994.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Move dwarf library related routines to dwarf-aux.{c,h}.
This includes several minor changes.
- Add simple documents for each API.
- Rename die_find_real_subprogram() to die_find_realfunc()
- Rename line_walk_handler_t to line_walk_callback_t.
- Minor cleanups.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
|
Namhyung Kim
Masami Hiramatsu (Google)
Yang Jihong
Ingo Molnar
Arnaldo Carvalho de Melo
Thomas Gleixner
Ravi Bangoria
Naveen N. Rao
He Kuang
Masami Hiramatsu