26 Feb, 2010
4 commits
-
Introduce kprobes jump optimization arch-independent parts.
Kprobes uses breakpoint instruction for interrupting execution
flow, on some architectures, it can be replaced by a jump
instruction and interruption emulation code. This gains kprobs'
performance drastically.To enable this feature, set CONFIG_OPTPROBES=y (default y if the
arch supports OPTPROBE).Changes in v9:
- Fix a bug to optimize probe when enabling.
- Check nearby probes can be optimize/unoptimize when disarming/arming
kprobes, instead of registering/unregistering. This will help
kprobe-tracer because most of probes on it are usually disabled.Changes in v6:
- Cleanup coding style for readability.
- Add comments around get/put_online_cpus().Changes in v5:
- Use get_online_cpus()/put_online_cpus() for avoiding text_mutex
deadlock.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Srikar Dronamraju
Cc: Christoph Hellwig
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Anders Kaseorg
Cc: Tim Abbott
Cc: Andi Kleen
Cc: Jason Baron
Cc: Mathieu Desnoyers
Cc: Frederic Weisbecker
Cc: Ananth N Mavinakayanahalli
LKML-Reference:
Signed-off-by: Ingo Molnar -
Make insn_slot framework support various size slots.
Current insn_slot just supports one-size instruction buffer
slot. However, kprobes jump optimization needs larger size
buffers.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Srikar Dronamraju
Cc: Christoph Hellwig
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Anders Kaseorg
Cc: Tim Abbott
Cc: Andi Kleen
Cc: Jason Baron
Cc: Mathieu Desnoyers
Cc: Frederic Weisbecker
Cc: Ananth N Mavinakayanahalli
LKML-Reference:
Signed-off-by: Ingo Molnar
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Srikar Dronamraju
Cc: Christoph Hellwig
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: H. Peter Anvin
Cc: Anders Kaseorg
Cc: Tim Abbott
Cc: Andi Kleen
Cc: Jason Baron
Cc: Mathieu Desnoyers -
Change RELATIVEJUMP_INSTRUCTION macro to RELATIVEJUMP_OPCODE
since it represents just the opcode byte.Signed-off-by: Masami Hiramatsu
Acked-by: Mathieu Desnoyers
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Srikar Dronamraju
Cc: Christoph Hellwig
Cc: Steven Rostedt
Cc: Frederic Weisbecker
Cc: Anders Kaseorg
Cc: Tim Abbott
Cc: Andi Kleen
Cc: Jason Baron
Cc: Mathieu Desnoyers
Cc: Frederic Weisbecker
Cc: Ananth N Mavinakayanahalli
LKML-Reference:
Signed-off-by: Ingo Molnar -
Because symbol->end is not fixed up at symbol_filter time, only
after all symbols for a DSO are loaded, and that, for asm
symbols, may be bogus, causing segfaults when hits happen in
these symbols.Reported-by: David Miller
Reported-by: Anton Blanchard
Acked-by: David Miller
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: # for .33.x. Does not apply cleanly, needs backport.
LKML-Reference:
Signed-off-by: Ingo Molnar
25 Feb, 2010
8 commits
-
Be more clear about DSO long names and tell from which file
kernel symbols were obtained, all in --verbose mode:[root@mica ~]# perf report -v > /dev/null
Looking at the vmlinux_path (5 entries long)
Using /lib/modules/2.6.33-rc8-tip-00777-g0918527-dirty/build/vmlinux for symbols
[root@mica ~]# mv /lib/modules/2.6.33-rc8-tip-00777-g0918527-dirty/build/vmlinux /tmp/dd
[root@mica ~]# perf report -v > /dev/null
Looking at the vmlinux_path (5 entries long)
Using /proc/kallsyms for symbols
[root@mica ~]#Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
To overcome a silly gcc warning:
cc1: warnings being treated as errors
builtin-top.c: In function ‘lookup_sym_source’:
builtin-top.c:291: warning: not protecting local variables:
variable length buffer make: *** [builtin-top.o] Error 1
make: *** Waiting for unfinished jobs....That is emitted for this:
const size_t pattern_len = BITS_PER_LONG / 4 + 2;
char pattern[pattern_len + 1];Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
[ -v2: macroify the naming style ]
Signed-off-by: Ingo Molnar -
In function dso__split_kallsyms(), curr_map saves the return value
of map__new2. So check it instead of var map after the call returns.Signed-off-by: Zhang Yanmin
Acked-by: David S. Miller
Cc: # for .33.x
Cc: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
syscall_name() helper, which resolves a syscall arch number to
its name, is not yet available as we first need to implement
event injection for it to work.Remove it from the documentation or tag its references as
unavailable yet. Once it's implemented, we can just revert
the current patch.Signed-off-by: Frederic Weisbecker
Cc: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo -
Also small update to perf-trace-perl and perf-trace docs.
Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
If we know the size of a tuple in advance, there's no need to resize
it - start out with the known size in the first place.Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
Adds a set of scripts that aggregate system call totals and system
call errors. Most are Python scripts that also test basic
functionality of the new Python engine, but there's also one Perl
script added for comparison and for reference in some new
Documentation contained in a later patch.Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
Add base support for Python scripting to perf trace.
Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker
24 Feb, 2010
5 commits
-
The check-perf-trace script only checks Perl functionality, and
doesn't really need to be listed as as user script anyway.This only removes the '-report' shell script, so although it doesn't
appear in the listing, the '-record' shell script and the check perf
trace perl script itself is still available and can still be run
manually as such:$ libexec/perf-core/scripts/perl/bin/check-perf-trace-record
$ perf trace -s libexec/perf-core/scripts/perl/check-perf-trace.plSigned-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
Create a scripting-engines directory to contain scripting engine
implementation code, in anticipation of the addition of new scripting
support. Also removes trace-event-perl.h.Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
This stuff is needed by all scripting engines; move it from the Perl
engine source to a more common place.Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
Fix bogus calculation.
Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker -
'perf trace -s list' prints a list of the supported scripting
languages. One problem with it is that it falls through and prints
the trace as well. The use of 'list' for this also makes it easy to
confuse with 'perf trace -l', used for listing available scripts. So
change 'perf trace -s list' to 'perf trace -s lang' and fixes the
fall-through problem.Signed-off-by: Tom Zanussi
Cc: Ingo Molnar
Cc: Steven Rostedt
Cc: Keiichi KII
Cc: Peter Zijlstra
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
LKML-Reference:
Signed-off-by: Frederic Weisbecker
22 Feb, 2010
2 commits
-
As the parent comm then is worthless, confusing users about the
thread where the sample really happened, leading to think that
the sample happened in the parent, not where it really happened,
in the children of a thread for which a PERF_RECORD_COMM event
was not received.Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
In 2161db9 we stopped failing when not finding modules when
asked too, but then the kernel maps (just one, for vmlinux)
wasn't having its ->end field correctly set up, so symbols were
not being found for the vmlinux map because its range was 0-0.Reported-by: Ingo Molnar
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar
08 Feb, 2010
4 commits
-
When 'perf record -g' a existing process, even with debuginfo
packages, still cannnot get symbol from 'perf report'.try:
perf record -g -p `pidof xxx` -f
perf report68.26% :1181 b74870f2 [.] 0x000000b74870f2
|
|--32.09%-- 0xb73b5b44
| 0xb7487102
| 0xb748a4e2
| 0xb748633d
| 0xb73b41cd
| 0xb73b4467
| 0xb747d531The reason is: for existing process, in __cmd_record(),
the pid is 0 rather than the existing process id.Signed-off-by: Austin Zhang
Acked-by: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
Fixes these warnings:
arch/x86/kernel/alternative.c: In function 'alternatives_text_reserved':
arch/x86/kernel/alternative.c:402: warning: comparison of distinct pointer types lacks a cast
arch/x86/kernel/alternative.c:402: warning: comparison of distinct pointer types lacks a cast
arch/x86/kernel/alternative.c:405: warning: comparison of distinct pointer types lacks a cast
arch/x86/kernel/alternative.c:405: warning: comparison of distinct pointer types lacks a castCaused by:
2cfa197: ftrace/alternatives: Introducing *_text_reserved functions
Changes in v2:
- Use local variables to compare, instead of type casts.Reported-by: Ingo Molnar
Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
LKML-Reference:
Signed-off-by: Ingo Molnar -
Because we may have aliases, like __GI___strcoll_l in
/lib64/libc-2.10.2.so that appears in objdump as:$ objdump --start-address=0x0000003715a86420 \
--stop-address=0x0000003715a872dc -dS /lib64/libc-2.10.2.so0000003715a86420 :
3715a86420: 55 push %rbp
3715a86421: 48 89 e5 mov %rsp,%rbp
3715a86424: 41 57 push %r15
[root@doppio linux-2.6-tip]#So look for the address exactly at the start of the line instead
so that annotation can work for in these cases.Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Kirill Smelkov
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
First, for programs and prelinked libraries, annotate code was
fooled by objdump output IPs (src->eip in the code) being
wrongly converted to absolute IPs. In such case there were no
conversion needed, but insrc->eip = strtoull(src->line, NULL, 16);
src->eip = map->unmap_ip(map, src->eip); // = eip + map->start - map->pgoffwe were reading absolute address from objdump (e.g. 8048604) and
then almost doubling it, because eip & map->start are
approximately close for small programs.Needless to say, that later, in record_precise_ip() there was no
matching with real runtime IPs.And second, like with `perf annotate` the problem with
non-prelinked *.so was that we were doing rip -> objdump address
conversion wrong.Also, because unlike `perf annotate`, `perf top` code does
annotation based on absolute IPs for performance reasons(*), new
helper for mapping objdump addresse to IP is introduced.(*) we get samples info in absolute IPs, and since we do lots of
hit-testing on absolute IPs at runtime in record_precise_ip(), it's
better to convert objdump addresses to IPs once and do no conversion
at runtime.I also had to fix how objdump output is parsed (with hardcoded
8/16 characters format, which was inappropriate for ET_DYN dsos
with small addresses like '4ac')Also note, that not all objdump output lines has associtated
IPs, e.g. look at source lines here:000004ac :
extern "C"
int my_strlen(const char *s)
4ac: 55 push %ebp
4ad: 89 e5 mov %esp,%ebp
4af: 83 ec 10 sub $0x10,%esp
{
int len = 0;
4b2: c7 45 fc 00 00 00 00 movl $0x0,-0x4(%ebp)
4b9: eb 08 jmp 4c3while (*s) {
++len;
4bb: 83 45 fc 01 addl $0x1,-0x4(%ebp)
++s;
4bf: 83 45 08 01 addl $0x1,0x8(%ebp)So we mark them with eip=0, and ignore such lines in annotate
lookup code.Signed-off-by: Kirill Smelkov
[ Note: one hunk of this patch was applied by Mike in 57d8188 ]
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Mike Galbraith
LKML-Reference:
Signed-off-by: Ingo Molnar
05 Feb, 2010
1 commit
-
Since mcount function can be called from everywhere,
it should be blacklisted. Moreover, the "mcount" symbol
is a special symbol name. So, it is better to put it in
the generic blacklist.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar
04 Feb, 2010
16 commits
-
perf top and perf record refuses to initialize on non-modular kernels:
refuse to initialize:$ perf top -v
map_groups__set_modules_path_dir: cannot open /lib/modules/2.6.33-rc6-tip-00586-g398dde3-dirty/Cc: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
Setting _FILE_OFFSET_BITS and using O_LARGEFILE, lseek64, etc,
is redundant. Thanks H. Peter Anvin for pointing it out.So, this patch removes O_LARGEFILE, lseek64, etc.
Suggested-by: "H. Peter Anvin"
Signed-off-by: Xiao Guangrong
Cc: Frederic Weisbecker
Cc: Steven Rostedt
Cc: Paul Mackerras
Cc: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
We cannot assume that because hwc->idx == assign[i], we can avoid
reprogramming the counter in hw_perf_enable().The event may have been scheduled out and another event may have been
programmed into this counter. Thus, we need a more robust way of
verifying if the counter still contains config/data related to an event.This patch adds a generation number to each counter on each cpu. Using
this mechanism we can verify reliabilty whether the content of a counter
corresponds to an event.Signed-off-by: Stephane Eranian
Signed-off-by: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
Avoid accidental misuse by failing to compile things
Suggested-by: Andrew Morton
Signed-off-by: Peter Zijlstra
Cc: Linus Torvalds
LKML-Reference:
Signed-off-by: Ingo Molnar -
Implement Intel Core Solo/Duo, aka.
Intel Architectural Performance Monitoring Version 1.Signed-off-by: Peter Zijlstra
Cc: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Arjan van de Ven
LKML-Reference:
Signed-off-by: Ingo Molnar -
Pretty much all of the calls do perf_disable/perf_enable cycles, pull
that out to cut back on hardware programming.Signed-off-by: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
Remove record freezing. Because kprobes never puts probe on
ftrace's mcount call anymore, it doesn't need ftrace to check
whether kprobes on it.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Steven Rostedt
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
Check whether the address of new probe is already reserved by
ftrace or alternatives (on x86) when registering new probe.
If reserved, it returns an error and not register the probe.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Steven Rostedt
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Mathieu Desnoyers
Cc: Jason Baron
LKML-Reference:
Signed-off-by: Ingo Molnar -
Introducing *_text_reserved functions for checking the text
address range is partially reserved or not. This patch provides
checking routines for x86 smp alternatives and dynamic ftrace.
Since both functions modify fixed pieces of kernel text, they
should reserve and protect those from other dynamic text
modifier, like kprobes.This will also be extended when introducing other subsystems
which modify fixed pieces of kernel text. Dynamic text modifiers
should avoid those.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Steven Rostedt
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker
Cc: Ananth N Mavinakayanahalli
Cc: Jim Keniston
Cc: Mathieu Desnoyers
Cc: Jason Baron
LKML-Reference:
Signed-off-by: Ingo Molnar -
Disable kprobe booster when CONFIG_PREEMPT=y at this time,
because it can't ensure that all kernel threads preempted on
kprobe's boosted slot run out from the slot even using
freeze_processes().The booster on preemptive kernel will be resumed if
synchronize_tasks() or something like that is introduced.Signed-off-by: Masami Hiramatsu
Cc: systemtap
Cc: DLE
Cc: Ananth N Mavinakayanahalli
Cc: Frederic Weisbecker
Cc: Jim Keniston
Cc: Mathieu Desnoyers
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
Signed-off-by: Mike Galbraith
Cc: Kirill Smelkov
Cc: Arnaldo Carvalho de Melo
Cc: Arnaldo Carvalho de Melo
Cc: Peter Zijlstra
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
By relying on logic in dso__load_kernel_sym(), we can
automatically load vmlinux.The only thing which needs to be adjusted, is how --sym-annotate
option is handled - now we can't rely on vmlinux been loaded
until full successful pass of dso__load_vmlinux(), but that's
not the case if we'll do sym_filter_entry setup in
symbol_filter().So move this step right after event__process_sample() where we
know the whole dso__load_kernel_sym() pass is done.By the way, though conceptually similar `perf top` still can't
annotate userspace - see next patches with fixes.Signed-off-by: Kirill Smelkov
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Mike Galbraith
LKML-Reference:
Signed-off-by: Ingo Molnar -
The problem was we were incorrectly calculating objdump
addresses for sym->start and sym->end, look:For simple ET_DYN type DSO (*.so) with one function, objdump -dS
output is something like this:000004ac :
int my_strlen(const char *s)
4ac: 55 push %ebp
4ad: 89 e5 mov %esp,%ebp
4af: 83 ec 10 sub $0x10,%esp
{i.e. we have relative-to-dso-mapping IPs (=RIP) there.
For ET_EXEC type and probably for prelinked libs as well (sorry
can't test - I don't use prelink) objdump outputs absolute IPs,
e.g.08048604 :
extern "C"
int zz_strlen(const char *s)
8048604: 55 push %ebp
8048605: 89 e5 mov %esp,%ebp
8048607: 83 ec 10 sub $0x10,%esp
{So, if sym->start is always relative to dso mapping(*), we'll
have to unmap it for ET_EXEC like cases, and leave as is for
ET_DYN cases.(*) and it is - we've explicitely made it relative. Look for
adjust_symbols handling in dso__load_sym()Previously we were always unmapping sym->start and for ET_DYN
dsos resulting addresses were wrong, and so objdump output was
empty.The end result was that perf annotate output for symbols from
non-prelinked *.so had always 0.00% percents only, which is
wrong.To fix it, let's introduce a helper for converting rip to
objdump address, and also let's document what map_ip() and
unmap_ip() do -- I had to study sources for several hours to
understand it.Signed-off-by: Kirill Smelkov
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Mike Galbraith
LKML-Reference:
Signed-off-by: Ingo Molnar -
Not to pollute too much 'perf annotate' debugging sessions.
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
We want to stream events as fast as possible to perf.data, and
also in the future we want to have splice working, when no
interception will be possible.Using build_id__mark_dso_hit_ops to create the list of DSOs that
back MMAPs we also optimize disk usage in the build-id cache by
only caching DSOs that had hits.Suggested-by: Peter Zijlstra
Signed-off-by: Arnaldo Carvalho de Melo
Cc: Xiao Guangrong
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar -
Because 'perf record' will have to find the build-ids in after
we stop recording, so as to reduce even more the impact in the
workload while we do the measurement.Signed-off-by: Arnaldo Carvalho de Melo
Cc: Frédéric Weisbecker
Cc: Mike Galbraith
Cc: Peter Zijlstra
Cc: Paul Mackerras
LKML-Reference:
Signed-off-by: Ingo Molnar
