Re: [PATCH 1/3 (fix commit message)] perf tools: Recognize hugetlb mapping as anon mapping

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sun, Sep 04, 2016 at 05:04:38AM +0000, Wang Nan escreveu:
> Hugetlbfs mapping should be recognized as anon mapping so user has
> a chance to create /tmp/perf-<pid>.map file for symbol resolving. This
> patch utilizes MAP_HUGETLB to identify hugetlb mapping.
> 
> After this patch, if perf is started before the program starts using
> huge pages (so perf gets MMAP2 events from kernel), perf is able to
> recognize hugetlb mapping as anon mapping.

Fixing build on older distros (Centos5, Ubuntu 12.04.5, etc)


  CC       /tmp/build/perf/arch/x86/util/perf_regs.o
util/event.c: In function 'perf_event__synthesize_mmap_events':
util/event.c:350: error: 'MAP_HUGETLB' undeclared (first use in this function)
util/event.c:350: error: (Each undeclared identifier is reported only once
util/event.c:350: error: for each function it appears in.)

 
> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
> Cc: He Kuang <hekuang@huawei.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Nilay Vaish <nilayvaish@gmail.com>
> ---
>  tools/perf/util/map.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index 728129a..a42010d 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -6,6 +6,7 @@
>  #include <string.h>
>  #include <stdio.h>
>  #include <unistd.h>
> +#include <sys/mman.h>
>  #include "map.h"
>  #include "thread.h"
>  #include "strlist.h"
> @@ -24,9 +25,10 @@ const char *map_type__name[MAP__NR_TYPES] = {
>  	[MAP__VARIABLE] = "Variables",
>  };
>  
> -static inline int is_anon_memory(const char *filename)
> +static inline int is_anon_memory(const char *filename, u32 flags)
>  {
> -	return !strcmp(filename, "//anon") ||
> +	return flags & MAP_HUGETLB ||
> +	       !strcmp(filename, "//anon") ||
>  	       !strncmp(filename, "/dev/zero", sizeof("/dev/zero") - 1) ||
>  	       !strncmp(filename, "/anon_hugepage", sizeof("/anon_hugepage") - 1);
>  }
> @@ -155,7 +157,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
>  		int anon, no_dso, vdso, android;
>  
>  		android = is_android_lib(filename);
> -		anon = is_anon_memory(filename);
> +		anon = is_anon_memory(filename, flags);
>  		vdso = is_vdso_map(filename);
>  		no_dso = is_no_dso_memory(filename);
>  
> -- 
> 1.8.3.4