Re: [PATCH 11/12] perf tools: Reuse shared eBPF dso objects

Jiri Olsa
2019-04-17T06:51:35Z

On Wed, Apr 17, 2019 at 09:35:32AM +0300, Adrian Hunter wrote:
> On 16/04/19 7:01 PM, Jiri Olsa wrote:
> > The eBPF program can be loaded multiple times
> > with the same name (tag). We can share dso
> > objects for those programs.
>
> Doesn't a eBPF program get recompiled differently every time it is loaded?

yes, but those with same tag are identical

jirka

>
> >
> > Link: http://lkml.kernel.org/n/tip-3damf8vq1dryhtpbk5b06jpt@git.kernel.org
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> > tools/perf/util/machine.c | 14 +++++++++++---
> > 1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> > index d4aa44489011..a60653827891 100644
> > --- a/tools/perf/util/machine.c
> > +++ b/tools/perf/util/machine.c
> > @@ -23,6 +23,7 @@
> > #include "linux/hash.h"
> > #include "asm/bug.h"
> > #include "bpf-event.h"
> > +#include "dso.h"
> >
> > #include "sane_ctype.h"
> > #include <symbol/kallsyms.h>
> > @@ -699,11 +700,18 @@ static int machine__process_ksymbol_register(struct machine *machine,
> >
> > map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
> > if (!map) {
> > - map = dso__new_map(event->ksymbol_event.name);
> > - if (!map)
> > + struct dso *dso;
> > +
> > + dso = dsos__findnew(&machine->dsos, event->ksymbol_event.name);
> > + if (!dso)
> > return -ENOMEM;
> >
> > - map->start = event->ksymbol_event.addr;
> > + map = map__new2(event->ksymbol_event.addr, dso);
> > + if (!map) {
> > + dso__put(dso);
> > + return -ENOMEM;
> > + }
> > +
> > map->end = map->start + event->ksymbol_event.len;
> > map_groups__insert(&machine->kmaps, map);
> > }
> >
>