[tip:perf/core] perf mmap: Fix perf backward recording

Commit-ID: 71f566a34986f4a86a8c546c7a36f70f0132b8a9 Gitweb: https://git.kernel.org/tip/71f566a34986f4a86a8c546c7a36f70f0132b8a9 Author: Wang Nan AuthorDate: Mon, 4 Dec 2017 16:51:05 + Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 5 Dec

[tip:perf/core] perf mmap: Fix perf backward recording

Commit-ID: 71f566a34986f4a86a8c546c7a36f70f0132b8a9 Gitweb: https://git.kernel.org/tip/71f566a34986f4a86a8c546c7a36f70f0132b8a9 Author: Wang Nan AuthorDate: Mon, 4 Dec 2017 16:51:05 + Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 5 Dec 2017 15:45:36 -0300 perf mmap: Fix