Messages in this thread Patch in this message | | | Date | Sat, 10 Mar 2018 17:50:56 +0800 | From | Leo Yan <> | Subject | Re: [PATCH v2] perf machine: Fix load kernel symbol with '-k' option |
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Hi Jiri,
On Fri, Mar 09, 2018 at 09:56:00PM +0100, Jiri Olsa wrote: > On Fri, Mar 09, 2018 at 02:05:23PM +0800, Leo Yan wrote: > > On Hikey arm64 octa A53 platform, when use command './perf report -v > > -k vmlinux --stdio' it outputs below error info, and it skips to load > > kernel symbol and doesn't print symbol for event: > > Failed to open [kernel.kallsyms]_text, continuing without symbols. > > > > The regression is introduced by commit ("8c7f1bb37b29 perf machine: Move > > kernel mmap name into struct machine"), which changes the logic for > > machine mmap_name by removing function machine__mmap_name() and always > > use 'machine->mmap_name'. Comparing difference between > > machine__mmap_name() and 'machine->mmap_name', the later one includes > > the string for specified kernel vmlinux string with option '-k' in > > command, but the old function machine__mmap_name() ignores vmlinux > > path string. As result, event's mmap file name doesn't match with > > machine mmap file name anymore and it skips to load kernel symbol from > > vmlinux file. > > > > To resolve this issue, this patch adds extra checking for > > 'symbol_conf.vmlinux_name', when it has been set string so we can know > > it includes vmlinux path string specified for option '-k'. For this > > case it sets 'is_kernel_mmap' to true and run into flow to load kernel > > symbol from vmlinux. > > > > This patch has been verified with two commands: './perf report -v > > -k vmlinux --stdio' and './perf script -v -F cpu,event,ip,sym,symoff > > -k vmlinux'. > > > > Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org> > > Signed-off-by: Leo Yan <leo.yan@linaro.org> > > --- > > tools/perf/util/machine.c | 15 ++++++++++++--- > > 1 file changed, 12 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > > index 12b7427..3125871 100644 > > --- a/tools/perf/util/machine.c > > +++ b/tools/perf/util/machine.c > > @@ -1299,9 +1299,18 @@ static int machine__process_kernel_mmap_event(struct machine *machine, > > else > > kernel_type = DSO_TYPE_GUEST_KERNEL; > > > > - is_kernel_mmap = memcmp(event->mmap.filename, > > - machine->mmap_name, > > - strlen(machine->mmap_name) - 1) == 0; > > + /* > > + * When symbol_conf.vmlinux_name is not NULL, it includes the specified > > + * kernel vmlinux path with option '-k'. So set 'is_kernel_mmap' to > > + * true for creating machine symbol map. > > + */ > > + if (symbol_conf.vmlinux_name) > > + is_kernel_mmap = true; > > + else > > + is_kernel_mmap = memcmp(event->mmap.filename, > > + machine->mmap_name, > > + strlen(machine->mmap_name) - 1) == 0; > > + > > if (event->mmap.filename[0] == '/' || > > (!is_kernel_mmap && event->mmap.filename[0] == '[')) { > > map = machine__findnew_module_map(machine, event->mmap.start, > > right, the mmap gets confused with the vmlinux path, but I wonder > the fix should be not to include symbol_conf.vmlinux_name in the > mmap_name like below.. untested
I tested below fixing at my side, and confirm your fixing also can resolve this issue. After reviewing the change, it's more neat than my own change . So you could add my test tag :)
Tested-by: Leo Yan <leo.yan@linaro.org>
BTW, I have a minor comment for code refactoring, it's up to you if need or not and if need use a new patch for refactoring, please see below inline comment.
Thanks, Leo Yan
> --- > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 43fbbee409ec..f0cb72022177 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -51,15 +51,9 @@ static void machine__threads_init(struct machine *machine) > static int machine__set_mmap_name(struct machine *machine) > { > if (machine__is_host(machine)) { > - if (symbol_conf.vmlinux_name) > - machine->mmap_name = strdup(symbol_conf.vmlinux_name); > - else > - machine->mmap_name = strdup("[kernel.kallsyms]"); > + machine->mmap_name = strdup("[kernel.kallsyms]"); > } else if (machine__is_default_guest(machine)) { > - if (symbol_conf.default_guest_vmlinux_name) > - machine->mmap_name = strdup(symbol_conf.default_guest_vmlinux_name); > - else > - machine->mmap_name = strdup("[guest.kernel.kallsyms]"); > + machine->mmap_name = strdup("[guest.kernel.kallsyms]"); > } else { > if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]", > machine->pid) < 0)
Do you think below format is better or not?
static int machine__set_mmap_name(struct machine *machine) { - if (machine__is_host(machine)) { - if (symbol_conf.vmlinux_name) - machine->mmap_name = strdup(symbol_conf.vmlinux_name); - else - machine->mmap_name = strdup("[kernel.kallsyms]"); - } else if (machine__is_default_guest(machine)) { - if (symbol_conf.default_guest_vmlinux_name) - machine->mmap_name = strdup(symbol_conf.default_guest_vmlinux_name); - else - machine->mmap_name = strdup("[guest.kernel.kallsyms]"); - } else { - if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]", - machine->pid) < 0) - machine->mmap_name = NULL; - } + if (machine__is_host(machine)) + machine->mmap_name = strdup("[kernel.kallsyms]"); + else if (machine__is_default_guest(machine)) + machine->mmap_name = strdup("[guest.kernel.kallsyms]"); + else if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]", + machine->pid) < 0) + machine->mmap_name = NULL; return machine->mmap_name ? 0 : -ENOMEM; }
> @@ -794,9 +788,15 @@ static struct dso *machine__get_kernel(struct machine *machine) > struct dso *kernel; > > if (machine__is_host(machine)) { > + if (symbol_conf.vmlinux_name) > + vmlinux_name = symbol_conf.vmlinux_name; > + > kernel = machine__findnew_kernel(machine, vmlinux_name, > "[kernel]", DSO_TYPE_KERNEL); > } else { > + if (symbol_conf.default_guest_vmlinux_name) > + vmlinux_name = symbol_conf.default_guest_vmlinux_name; > + > kernel = machine__findnew_kernel(machine, vmlinux_name, > "[guest.kernel]", > DSO_TYPE_GUEST_KERNEL);
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