[PATCH] perf lzma: Quieten lzma warning

[PATCH] perf lzma: Quieten lzma warning

[Andi Kleen]

On my Fedora system which is missing some modules I always get a long flood
of

lzma: fopen failed on /usr/lib/modules/5.3.9-300.fc31.x86_64/kernel/sound/pci/hda/snd-hda-codec.ko.xz: 'No such file or directory'
lzma: fopen failed on /usr/lib/modules/5.16.7-200.fc35.x86_64/kernel/sound/pci/hda/snd-hda-intel.ko.xz: 'No such file or directory'
lzma: fopen failed on /usr/lib/modules/5.1.11-200.fc29.x86_64/kernel/drivers/vhost/vhost_net.ko.xz: 'No such file or directory'

for each use of "perf list".

Disable the message.

Also I'm not sure why it's looking at the modules of each kernel, not
just the running one, but that's a different problem.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
 tools/perf/util/lzma.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
index 51424cdc3b68..ef0520c82245 100644
--- a/tools/perf/util/lzma.c
+++ b/tools/perf/util/lzma.c
@@ -44,11 +44,8 @@ int lzma_decompress_to_file(const char *input, int output_fd)
 	FILE *infile;
 
 	infile = fopen(input, "rb");
-	if (!infile) {
-		pr_err("lzma: fopen failed on %s: '%s'\n",
-		       input, strerror(errno));
+	if (!infile)
 		return -1;
-	}
 
 	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
 	if (ret != LZMA_OK) {
-- 
2.37.2

Re: [PATCH] perf lzma: Quieten lzma warning

[Arnaldo Carvalho de Melo]

Em Tue, Oct 04, 2022 at 12:06:15PM -0700, Andi Kleen escreveu:
> On my Fedora system which is missing some modules I always get a long flood
> of
> 
> lzma: fopen failed on /usr/lib/modules/5.3.9-300.fc31.x86_64/kernel/sound/pci/hda/snd-hda-codec.ko.xz: 'No such file or directory'
> lzma: fopen failed on /usr/lib/modules/5.16.7-200.fc35.x86_64/kernel/sound/pci/hda/snd-hda-intel.ko.xz: 'No such file or directory'
> lzma: fopen failed on /usr/lib/modules/5.1.11-200.fc29.x86_64/kernel/drivers/vhost/vhost_net.ko.xz: 'No such file or directory'
> 
> for each use of "perf list".
> 
> Disable the message.
> 
> Also I'm not sure why it's looking at the modules of each kernel, not
> just the running one, but that's a different problem.

Yeah, I see this from time to time, would be interesting to find the
root cause for looking at te modules for each kernel :-\

I'll try to take a look if Jiri doesn't have any idea about this.

- Arnaldo
 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  tools/perf/util/lzma.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
> index 51424cdc3b68..ef0520c82245 100644
> --- a/tools/perf/util/lzma.c
> +++ b/tools/perf/util/lzma.c
> @@ -44,11 +44,8 @@ int lzma_decompress_to_file(const char *input, int output_fd)
>  	FILE *infile;
>  
>  	infile = fopen(input, "rb");
> -	if (!infile) {
> -		pr_err("lzma: fopen failed on %s: '%s'\n",
> -		       input, strerror(errno));
> +	if (!infile)
>  		return -1;
> -	}
>  
>  	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
>  	if (ret != LZMA_OK) {
> -- 
> 2.37.2

-- 

- Arnaldo

Re: [PATCH] perf lzma: Quieten lzma warning

[Arnaldo Carvalho de Melo]

Em Tue, Oct 04, 2022 at 12:06:15PM -0700, Andi Kleen escreveu:
> On my Fedora system which is missing some modules I always get a long flood
> of
> 
> lzma: fopen failed on /usr/lib/modules/5.3.9-300.fc31.x86_64/kernel/sound/pci/hda/snd-hda-codec.ko.xz: 'No such file or directory'
> lzma: fopen failed on /usr/lib/modules/5.16.7-200.fc35.x86_64/kernel/sound/pci/hda/snd-hda-intel.ko.xz: 'No such file or directory'
> lzma: fopen failed on /usr/lib/modules/5.1.11-200.fc29.x86_64/kernel/drivers/vhost/vhost_net.ko.xz: 'No such file or directory'
> 
> for each use of "perf list".
> 
> Disable the message.
> 
> Also I'm not sure why it's looking at the modules of each kernel, not
> just the running one, but that's a different problem.

So using:

[root@five ~]# perf probe -x ~/bin/perf -L lzma_decompress_to_file | head -20
<lzma_decompress_to_file@/var/home/acme/git/perf/tools/perf/util/lzma.c:0>
      0  int lzma_decompress_to_file(const char *input, int output_fd)
         {
      2  	lzma_action action = LZMA_RUN;
         	lzma_stream strm   = LZMA_STREAM_INIT;
      4  	lzma_ret ret;
         	int err = -1;
         
         	u8 buf_in[BUFSIZE];
         	u8 buf_out[BUFSIZE];
         	FILE *infile;
         
         	infile = fopen(input, "rb");
     12  	if (!infile) {
     13  		pr_err("lzma: fopen failed on %s: '%s'\n",
         		       input, strerror(errno));
     15  		return -1;
         	}
         
     18  	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
[root@five ~]#

And:

[root@five ~]# perf probe -x ~/bin/perf lzma_decompress_to_file
Added new event:
  probe_perf:lzma_decompress_to_file (on lzma_decompress_to_file in /var/home/acme/bin/perf)

You can now use it in all perf tools, such as:

	perf record -e probe_perf:lzma_decompress_to_file -aR sleep 1

[root@five ~]#
[root@five ~]# perf record -e probe_perf:lzma_decompress_to_file/max-stack=16/ perf list syscalls:sys_enter_open*
[ perf record: Woken up 1 times to write data ]

[ perf record: Captured and wrote 0.119 MB perf.data (625 samples) ]

[root@five ~]#
[root@five ~]#
[root@five ~]# perf report --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 625  of event 'probe_perf:lzma_decompress_to_file'
# Event count (approx.): 625
#
# Children      Self  Trace output
# ........  ........  ............
#
   100.00%   100.00%  (5c53b0)
            |
            ---__libc_start_call_main
               main
               run_builtin
               cmd_list
               print_sdt_events
               build_id_cache__list_all
               filename__read_build_id
               lzma_decompress_to_file



#
# (Tip: Limit to show entries above 5% only: perf report --percent-limit 5)
#
[root@five ~]#


Seems like it is trying to find SDT events in everything that is in
~/.debug :-\ I'll try to continue this later, sidetracked now.

- Arnaldo
 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  tools/perf/util/lzma.c | 5 +----
>  1 file changed, 1 insertion(+), 4 deletions(-)
> 
> diff --git a/tools/perf/util/lzma.c b/tools/perf/util/lzma.c
> index 51424cdc3b68..ef0520c82245 100644
> --- a/tools/perf/util/lzma.c
> +++ b/tools/perf/util/lzma.c
> @@ -44,11 +44,8 @@ int lzma_decompress_to_file(const char *input, int output_fd)
>  	FILE *infile;
>  
>  	infile = fopen(input, "rb");
> -	if (!infile) {
> -		pr_err("lzma: fopen failed on %s: '%s'\n",
> -		       input, strerror(errno));
> +	if (!infile)
>  		return -1;
> -	}
>  
>  	ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED);
>  	if (ret != LZMA_OK) {
> -- 
> 2.37.2

-- 

- Arnaldo