Date: Tue, 8 Oct 2013 11:36:38 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Stephane Eranian <eranian@google.com>
Cc: Kees Cook <keescook@chromium.org>, Ingo Molnar <mingo@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>, "mingo@elte.hu" <mingo@elte.hu>,
        "ak@linux.intel.com" <ak@linux.intel.com>,
        Arnaldo Carvalho de Melo <acme@redhat.com>,
        David Ahern <dsahern@gmail.com>, Jiri Olsa <jolsa@redhat.com>,
        Hugh Dickins <hughd@google.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC] perf: mmap2 not covering VM_CLONE regions
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On Tue, Oct 08, 2013 at 09:15:30AM +0200, Stephane Eranian wrote:
> Yes, it is but I am trying to see whether or not we could unify that and
> use a single u64 number to uniquely identify each mapping.

No you cannot; two unrelated executables which have distinct mm_ids can
easily mmap() the same shared file.
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