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Date:   Thu, 14 Feb 2019 13:26:38 +0100
From:   Jiri Olsa <jolsa@redhat.com>
To:     Song Liu <songliubraving@fb.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        ast@kernel.org, daniel@iogearbox.net, kernel-team@fb.com,
        peterz@infradead.org, acme@redhat.com
Subject: Re: [PATCH 5/9] perf, bpf: save bpf_prog_info in a rbtree in perf_env
Message-ID: <20190214122638.GD26714@krava>
References: <20190209011705.2160185-1-songliubraving@fb.com>
 <20190209011705.2160185-6-songliubraving@fb.com>
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On Fri, Feb 08, 2019 at 05:17:01PM -0800, Song Liu wrote:

SNIP

> diff --git a/tools/perf/util/env.h b/tools/perf/util/env.h
> index d01b8355f4ca..5894a177b7cf 100644
> --- a/tools/perf/util/env.h
> +++ b/tools/perf/util/env.h
> @@ -3,7 +3,10 @@
>  #define __PERF_ENV_H
>  
>  #include <linux/types.h>
> +#include <linux/rbtree.h>
>  #include "cpumap.h"
> +#include "rwsem.h"
> +#include "bpf-event.h"
>  
>  struct cpu_topology_map {
>  	int	socket_id;
> @@ -64,6 +67,8 @@ struct perf_env {
>  	struct memory_node	*memory_nodes;
>  	unsigned long long	 memory_bsize;
>  	u64                     clockid_res_ns;
> +	struct rw_semaphore	bpf_info_lock;

why's the lock needed?

jirka