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 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;
