Em Mon, May 18, 2020 at 09:03:45AM -0700, Ian Rogers escreveu: > On Mon, May 18, 2020 at 8:45 AM Arnaldo Carvalho de Melo > <arnaldo.melo@xxxxxxxxx> wrote: > > > > Em Fri, May 15, 2020 at 03:17:32PM -0700, Ian Rogers escreveu: > > > Use a hashmap between a char* string and a double* value. While bpf's > > > hashmap entries are size_t in size, we can't guarantee sizeof(size_t) >= > > > sizeof(double). Avoid a memory allocation when gathering ids by making 0.0 > > > a special value encoded as NULL. > > > > > > Original map suggestion by Andi Kleen: > > > https://lore.kernel.org/lkml/20200224210308.GQ160988@xxxxxxxxxxxxxxxxxxxx/ > > > and seconded by Jiri Olsa: > > > https://lore.kernel.org/lkml/20200423112915.GH1136647@krava/ > > > > I'm having trouble here when building it with: > > > > make -C tools/perf O=/tmp/build/perf > > > > CC /tmp/build/perf/tests/expr.o > > INSTALL trace_plugins > > CC /tmp/build/perf/util/metricgroup.o > > In file included from /home/acme/git/perf/tools/lib/bpf/hashmap.h:18, > > from /home/acme/git/perf/tools/perf/util/expr.h:6, > > from tests/expr.c:3: > > /home/acme/git/perf/tools/lib/bpf/libbpf_internal.h:63: error: "pr_info" redefined [-Werror] > > 63 | #define pr_info(fmt, ...) __pr(LIBBPF_INFO, fmt, ##__VA_ARGS__) > > | > > In file included from tests/expr.c:2: > > /home/acme/git/perf/tools/perf/util/debug.h:24: note: this is the location of the previous definition > > > > It looks like libbpf's hashmap.h is being used instead of the one in > > tools/perf/util/, yeah, as intended, but then since I don't have the > > fixes you added to the BPF tree, the build fails, if I instead > > unconditionally use > > > > #include "util/hashmap.h" > > > > It works. Please ack. > > > > I.e. with the patch below, further tests: > > > > [acme@five perf]$ perf -vv | grep -i bpf > > bpf: [ on ] # HAVE_LIBBPF_SUPPORT > > [acme@five perf]$ nm ~/bin/perf | grep -i libbpf_ | wc -l > > 39 > > [acme@five perf]$ nm ~/bin/perf | grep -i hashmap_ | wc -l > > 17 > > [acme@five perf]$ > > > > Explicitely building without LIBBPF: > > > > [acme@five perf]$ perf -vv | grep -i bpf > > bpf: [ OFF ] # HAVE_LIBBPF_SUPPORT > > [acme@five perf]$ > > [acme@five perf]$ nm ~/bin/perf | grep -i libbpf_ | wc -l > > 0 > > [acme@five perf]$ nm ~/bin/perf | grep -i hashmap_ | wc -l > > 9 > > [acme@five perf]$ > > > > Works, > > > > - Arnaldo > > Hi Arnaldo, > > this build issue sounds like this patch is missing: > https://lore.kernel.org/lkml/20200515221732.44078-3-irogers@xxxxxxxxxx/ > The commit message there could have explicitly said having this > #include causes the conflicting definitions between perf's debug.h and > libbpf_internal.h's definitions of pr_info, etc. yeah, understood, but I'm not processing patches for tools/lib/bpf/, Daniel is, I'll only get that one later, then we can go back to the way you structured it. Just an extra bit of confusion in this process ;-) > Let me know how else to help and sorry for the confusion. Thanks, > Ian > > > > diff --git a/tools/perf/util/expr.h b/tools/perf/util/expr.h > > index d60a8feaf50b..8a2c1074f90f 100644 > > --- a/tools/perf/util/expr.h > > +++ b/tools/perf/util/expr.h > > @@ -2,11 +2,14 @@ > > #ifndef PARSE_CTX_H > > #define PARSE_CTX_H 1 > > > > -#ifdef HAVE_LIBBPF_SUPPORT > > -#include <bpf/hashmap.h> > > -#else > > -#include "hashmap.h" > > -#endif > > +// There are fixes that need to land upstream before we can use libbpf's headers, > > +// for now use our copy unconditionally, since the data structures at this point > > +// are exactly the same, no problem. > > +//#ifdef HAVE_LIBBPF_SUPPORT > > +//#include <bpf/hashmap.h> > > +//#else > > +#include "util/hashmap.h" > > +//#endif > > > > struct expr_parse_ctx { > > struct hashmap ids; -- - Arnaldo
