Re: "perf record" if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)

[Alexey Brodkin <Alexey.Brodkin@synopsys.com>]

Hi Adrian,

On Tue, 2015-07-14 at 15:36 +0300, Adrian Hunter wrote:
> On 14/07/15 15:12, Alexey Brodkin wrote:
> How about this:
> 
> From: Adrian Hunter <adrian.hunter@intel.com>
> Date: Tue, 14 Jul 2015 15:32:41 +0300
> Subject: [PATCH] perf tools: Fix misplaced check for
>  HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT
> 
> Move the checking for HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT
> for AUX area mmaps until after checking if such mmaps are
> used anyway.
> 
> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>  tools/perf/util/auxtrace.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
> index 7e7405c9b936..83d9dd96fe08 100644
> --- a/tools/perf/util/auxtrace.c
> +++ b/tools/perf/util/auxtrace.c
> @@ -53,11 +53,6 @@ int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
>  {
>  	struct perf_event_mmap_page *pc = userpg;
>  
> -#if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)
> -	pr_err("Cannot use AUX area tracing mmaps\n");
> -	return -1;
> -#endif
> -
>  	WARN_ONCE(mm->base, "Uninitialized auxtrace_mmap\n");
>  
>  	mm->userpg = userpg;
> @@ -73,6 +68,11 @@ int auxtrace_mmap__mmap(struct auxtrace_mmap *mm,
>  		return 0;
>  	}
>  
> +#if BITS_PER_LONG != 64 && !defined(HAVE_SYNC_COMPARE_AND_SWAP_SUPPORT)
> +	pr_err("Cannot use AUX area tracing mmaps\n");
> +	return -1;
> +#endif
> +
>  	pc->aux_offset = mp->offset;
>  	pc->aux_size = mp->len;

That was really fast!

And indeed fixes reported problem with "record".
 --------------------------->8-------------------------
# perf record ls -la
total 32
drwx------    2 root     root           140 Jan  1 00:00 .
drwxrwxr-x   18 root     root           420 Jul 14  2015 ..
-rw-------    1 root     root            19 Jan  1 00:00 .ash_history
-rw-rw-r--    1 root     root             0 Jul 14  2015 .bash_history
-rw-rw-r--    1 root     root           175 Jul 14  2015 .bash_logout
-rw-rw-r--    1 root     root            78 Jul 14  2015 .bash_profile
-rw-------    1 root     root           312 Jan  1 00:00 perf.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.059 MB perf.data (1528 samples) ]

# perf report
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 1K of event 'cycles'
# Event count (approx.): 2902149
#
# Overhead  Command  Shared Object            Symbol                                
# ........  .......  .......................  ......................................
#
     7.37%  ls       libuClibc-0.9.34-git.so  [.] _ppfs_parsespec                   
     4.40%  ls       [kernel.kallsyms]        [k] memset                            
     3.96%  ls       [kernel.kallsyms]        [k] aligndestination                  
     3.74%  ls       ld-uClibc-0.9.34-git.so  [.] _dl_find_hash                     
     2.34%  ls       [kernel.kallsyms]        [k] perf_event_exec                   
     2.28%  ls       [kernel.kallsyms]        [k] flush_signal_handlers             
     2.28%  ls       [kernel.kallsyms]        [k] _raw_spin_unlock_irqrestore       
     1.77%  ls       libuClibc-0.9.34-git.so  [.] __stdio_fwrite                    
     1.43%  ls       [kernel.kallsyms]        [k] copy_page_to_iter                 
     1.36%  ls       libuClibc-0.9.34-git.so  [.] _ppfs_init                        
     1.22%  ls       [kernel.kallsyms]        [k] filemap_map_pages 
 --------------------------->8-------------------------

Thanks a lot for your prompt response.
Feel free to add my Tested-by then.

-Alexey