| Message ID | 20130924174318.GE3080@krava.brq.redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Jiri, On 24 September 2013 19:43, Jiri Olsa <jolsa@redhat.com> wrote: > On Tue, Sep 24, 2013 at 02:03:47PM +0200, Jean Pihet wrote: >> Hi Jiri, Will, >> >> On 24 September 2013 12:06, Will Deacon <will.deacon@arm.com> wrote: >> > On Tue, Sep 24, 2013 at 10:34:50AM +0100, Jiri Olsa wrote: >> >> On Tue, Sep 24, 2013 at 10:55:32AM +0200, Jean Pihet wrote: >> >> > Ping on the series. The two patches above (3/4 and 4/4) are generic >> >> > while the two others are impacting ARM only. >> >> > Is it possible to get an Ack for the generic ones? >> >> >> >> I'm fine with those changes.. still I'm sort of worried about >> >> current DWARF unwind users (but not sure if there're any), >> >> who depends on packaged libunwind compiled without >> >> --enable-debug-frame option. >> > >> > Since x86 is the only architecture using libunwind with perf at the moment, >> > and I'd expect it to use .eh_frame for unwinding, I'm also not sure there >> > are any existing users to worry about. >> Right >> >> > >> >> I've seen your libunwind patch to make it default, but >> >> not sure if it was accepted.. if not, maybe we should >> >> detect this and build that code conditionaly. >> > >> > It certainly defaults to "on" for ARM, but other architectures have to >> > enable it explicitly afaict. >> Yes that is correct. >> This patch (3/4) detects if the debug frame code is enabled in >> libunwind and uses the lib only if it is the case. > > My concern is about users (again, not sure if there are any ;-) ) > that use this with packaged libunwind compiled without > --enable-debug-frame option. > > For them perf will consider libunwind as 'not available' with > your changes: > > ... > CHK libunwind > config/Makefile:223: No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1 > ... > > and they'll need to compile their own libunwind > (thats the case on Fedora). > > This could be solved by detecting this and make your > code conditional as attached below (not much tested). Ok that makes sense. Let me integrate this in the patch series, test it (on ARM and x86) and re-submit. Is that OK? Regards, Jean > > thanks, > jirka > > > --- > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile > index 134b36e..d40cf0a 100644 > --- a/tools/perf/config/Makefile > +++ b/tools/perf/config/Makefile > @@ -223,6 +223,10 @@ ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y) > msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1); > NO_LIBUNWIND := 1 > endif # Libunwind support > +ifneq ($(call try-cc,$(SOURCE_LIBUNWIND_DEBUG_FRAME),$(FLAGS_UNWIND),libunwind debug_frame),y) > + msg := $(warning No debug_frame support found in libunwind); > +CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME > +endif > endif # NO_LIBUNWIND > > ifndef NO_LIBUNWIND > diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak > index 87124d0..645141c 100644 > --- a/tools/perf/config/feature-tests.mak > +++ b/tools/perf/config/feature-tests.mak > @@ -178,6 +178,28 @@ extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, > > #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) > > +int main(void) > +{ > + unw_addr_space_t addr_space; > + addr_space = unw_create_addr_space(NULL, 0); > + unw_init_remote(NULL, addr_space, NULL); > + dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL); > + return 0; > +} > +endef > + > +define SOURCE_LIBUNWIND_DEBUG_FRAME > +#include <libunwind.h> > +#include <stdlib.h> > + > +extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, > + unw_word_t ip, > + unw_dyn_info_t *di, > + unw_proc_info_t *pi, > + int need_unwind_info, void *arg); > + > +#define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) > + > extern int > UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, > unw_word_t ip, > @@ -189,11 +211,7 @@ UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, > > int main(void) > { > - unw_addr_space_t addr_space; > - addr_space = unw_create_addr_space(NULL, 0); > - unw_init_remote(NULL, addr_space, NULL); > dwarf_find_debug_frame(0, NULL, 0, 0, NULL, 0, 0); > - dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL); > return 0; > } > endef > diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c > index 429a99c..231c941 100644 > --- a/tools/perf/util/unwind.c > +++ b/tools/perf/util/unwind.c > @@ -277,6 +277,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, > return ret; > } > > +#ifndef NO_LIBUNWIND_DEBUG_FRAME > static int read_unwind_spec_debug_frame(struct dso *dso, > struct machine *machine, u64 *offset) > { > @@ -294,6 +295,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso, > > return -EINVAL; > } > +#endif > > static struct map *find_map(unw_word_t ip, struct unwind_info *ui) > { > @@ -334,6 +336,7 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, > need_unwind_info, arg); > } > > +#ifndef NO_LIBUNWIND_DEBUG_FRAME > /* Check the .debug_frame section for unwinding info */ > if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { > memset(&di, 0, sizeof(di)); > @@ -342,7 +345,7 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, > return dwarf_search_unwind_table(as, ip, &di, pi, > need_unwind_info, arg); > } > - > +#endif > return -EINVAL; > } >
On Wed, Sep 25, 2013 at 08:53:44AM +0200, Jean Pihet wrote: > Hi Jiri, > > On 24 September 2013 19:43, Jiri Olsa <jolsa@redhat.com> wrote: > > On Tue, Sep 24, 2013 at 02:03:47PM +0200, Jean Pihet wrote: > >> Hi Jiri, Will, > >> > >> On 24 September 2013 12:06, Will Deacon <will.deacon@arm.com> wrote: > >> > On Tue, Sep 24, 2013 at 10:34:50AM +0100, Jiri Olsa wrote: > >> >> On Tue, Sep 24, 2013 at 10:55:32AM +0200, Jean Pihet wrote: > >> >> > Ping on the series. The two patches above (3/4 and 4/4) are generic > >> >> > while the two others are impacting ARM only. > >> >> > Is it possible to get an Ack for the generic ones? > >> >> > >> >> I'm fine with those changes.. still I'm sort of worried about > >> >> current DWARF unwind users (but not sure if there're any), > >> >> who depends on packaged libunwind compiled without > >> >> --enable-debug-frame option. > >> > > >> > Since x86 is the only architecture using libunwind with perf at the moment, > >> > and I'd expect it to use .eh_frame for unwinding, I'm also not sure there > >> > are any existing users to worry about. > >> Right > >> > >> > > >> >> I've seen your libunwind patch to make it default, but > >> >> not sure if it was accepted.. if not, maybe we should > >> >> detect this and build that code conditionaly. > >> > > >> > It certainly defaults to "on" for ARM, but other architectures have to > >> > enable it explicitly afaict. > >> Yes that is correct. > >> This patch (3/4) detects if the debug frame code is enabled in > >> libunwind and uses the lib only if it is the case. > > > > My concern is about users (again, not sure if there are any ;-) ) > > that use this with packaged libunwind compiled without > > --enable-debug-frame option. > > > > For them perf will consider libunwind as 'not available' with > > your changes: > > > > ... > > CHK libunwind > > config/Makefile:223: No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1 > > ... > > > > and they'll need to compile their own libunwind > > (thats the case on Fedora). > > > > This could be solved by detecting this and make your > > code conditional as attached below (not much tested). > Ok that makes sense. > Let me integrate this in the patch series, test it (on ARM and x86) > and re-submit. Is that OK? that'd be great thanks, jirka
Hi Jiri, Will, I just sent the reworked series as '[PATCH v3 0/4] perf: parse the dwarf backtrace info from .debug_frame section'. Tested on x86 and ARMv7. Regards, Jean On 25 September 2013 09:31, Jiri Olsa <jolsa@redhat.com> wrote: > On Wed, Sep 25, 2013 at 08:53:44AM +0200, Jean Pihet wrote: >> Hi Jiri, >> >> On 24 September 2013 19:43, Jiri Olsa <jolsa@redhat.com> wrote: >> > On Tue, Sep 24, 2013 at 02:03:47PM +0200, Jean Pihet wrote: >> >> Hi Jiri, Will, >> >> >> >> On 24 September 2013 12:06, Will Deacon <will.deacon@arm.com> wrote: >> >> > On Tue, Sep 24, 2013 at 10:34:50AM +0100, Jiri Olsa wrote: >> >> >> On Tue, Sep 24, 2013 at 10:55:32AM +0200, Jean Pihet wrote: >> >> >> > Ping on the series. The two patches above (3/4 and 4/4) are generic >> >> >> > while the two others are impacting ARM only. >> >> >> > Is it possible to get an Ack for the generic ones? >> >> >> >> >> >> I'm fine with those changes.. still I'm sort of worried about >> >> >> current DWARF unwind users (but not sure if there're any), >> >> >> who depends on packaged libunwind compiled without >> >> >> --enable-debug-frame option. >> >> > >> >> > Since x86 is the only architecture using libunwind with perf at the moment, >> >> > and I'd expect it to use .eh_frame for unwinding, I'm also not sure there >> >> > are any existing users to worry about. >> >> Right >> >> >> >> > >> >> >> I've seen your libunwind patch to make it default, but >> >> >> not sure if it was accepted.. if not, maybe we should >> >> >> detect this and build that code conditionaly. >> >> > >> >> > It certainly defaults to "on" for ARM, but other architectures have to >> >> > enable it explicitly afaict. >> >> Yes that is correct. >> >> This patch (3/4) detects if the debug frame code is enabled in >> >> libunwind and uses the lib only if it is the case. >> > >> > My concern is about users (again, not sure if there are any ;-) ) >> > that use this with packaged libunwind compiled without >> > --enable-debug-frame option. >> > >> > For them perf will consider libunwind as 'not available' with >> > your changes: >> > >> > ... >> > CHK libunwind >> > config/Makefile:223: No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1 >> > ... >> > >> > and they'll need to compile their own libunwind >> > (thats the case on Fedora). >> > >> > This could be solved by detecting this and make your >> > code conditional as attached below (not much tested). >> Ok that makes sense. >> Let me integrate this in the patch series, test it (on ARM and x86) >> and re-submit. Is that OK? > > that'd be great > > thanks, > jirka
diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile index 134b36e..d40cf0a 100644 --- a/tools/perf/config/Makefile +++ b/tools/perf/config/Makefile @@ -223,6 +223,10 @@ ifneq ($(call try-cc,$(SOURCE_LIBUNWIND),$(FLAGS_UNWIND),libunwind),y) msg := $(warning No libunwind found, disabling post unwind support. Please install libunwind-dev[el] >= 1.1); NO_LIBUNWIND := 1 endif # Libunwind support +ifneq ($(call try-cc,$(SOURCE_LIBUNWIND_DEBUG_FRAME),$(FLAGS_UNWIND),libunwind debug_frame),y) + msg := $(warning No debug_frame support found in libunwind); +CFLAGS += -DNO_LIBUNWIND_DEBUG_FRAME +endif endif # NO_LIBUNWIND ifndef NO_LIBUNWIND diff --git a/tools/perf/config/feature-tests.mak b/tools/perf/config/feature-tests.mak index 87124d0..645141c 100644 --- a/tools/perf/config/feature-tests.mak +++ b/tools/perf/config/feature-tests.mak @@ -178,6 +178,28 @@ extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, #define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) +int main(void) +{ + unw_addr_space_t addr_space; + addr_space = unw_create_addr_space(NULL, 0); + unw_init_remote(NULL, addr_space, NULL); + dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL); + return 0; +} +endef + +define SOURCE_LIBUNWIND_DEBUG_FRAME +#include <libunwind.h> +#include <stdlib.h> + +extern int UNW_OBJ(dwarf_search_unwind_table) (unw_addr_space_t as, + unw_word_t ip, + unw_dyn_info_t *di, + unw_proc_info_t *pi, + int need_unwind_info, void *arg); + +#define dwarf_search_unwind_table UNW_OBJ(dwarf_search_unwind_table) + extern int UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, unw_word_t ip, @@ -189,11 +211,7 @@ UNW_OBJ(dwarf_find_debug_frame) (int found, unw_dyn_info_t *di_debug, int main(void) { - unw_addr_space_t addr_space; - addr_space = unw_create_addr_space(NULL, 0); - unw_init_remote(NULL, addr_space, NULL); dwarf_find_debug_frame(0, NULL, 0, 0, NULL, 0, 0); - dwarf_search_unwind_table(addr_space, 0, NULL, NULL, 0, NULL); return 0; } endef diff --git a/tools/perf/util/unwind.c b/tools/perf/util/unwind.c index 429a99c..231c941 100644 --- a/tools/perf/util/unwind.c +++ b/tools/perf/util/unwind.c @@ -277,6 +277,7 @@ static int read_unwind_spec_eh_frame(struct dso *dso, struct machine *machine, return ret; } +#ifndef NO_LIBUNWIND_DEBUG_FRAME static int read_unwind_spec_debug_frame(struct dso *dso, struct machine *machine, u64 *offset) { @@ -294,6 +295,7 @@ static int read_unwind_spec_debug_frame(struct dso *dso, return -EINVAL; } +#endif static struct map *find_map(unw_word_t ip, struct unwind_info *ui) { @@ -334,6 +336,7 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, need_unwind_info, arg); } +#ifndef NO_LIBUNWIND_DEBUG_FRAME /* Check the .debug_frame section for unwinding info */ if (!read_unwind_spec_debug_frame(map->dso, ui->machine, &segbase)) { memset(&di, 0, sizeof(di)); @@ -342,7 +345,7 @@ find_proc_info(unw_addr_space_t as, unw_word_t ip, unw_proc_info_t *pi, return dwarf_search_unwind_table(as, ip, &di, pi, need_unwind_info, arg); } - +#endif return -EINVAL; }