diff options
Diffstat (limited to 'include/linux/perf_counter.h')
-rw-r--r-- | include/linux/perf_counter.h | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index f2b914de3f0c..e22ab47a2f41 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h | |||
@@ -170,22 +170,18 @@ struct perf_counter_mmap_page { | |||
170 | * u32 seq; | 170 | * u32 seq; |
171 | * s64 count; | 171 | * s64 count; |
172 | * | 172 | * |
173 | * again: | 173 | * do { |
174 | * seq = pc->lock; | 174 | * seq = pc->lock; |
175 | * if (unlikely(seq & 1)) { | ||
176 | * cpu_relax(); | ||
177 | * goto again; | ||
178 | * } | ||
179 | * | 175 | * |
180 | * if (pc->index) { | 176 | * barrier() |
181 | * count = pmc_read(pc->index - 1); | 177 | * if (pc->index) { |
182 | * count += pc->offset; | 178 | * count = pmc_read(pc->index - 1); |
183 | * } else | 179 | * count += pc->offset; |
184 | * goto regular_read; | 180 | * } else |
181 | * goto regular_read; | ||
185 | * | 182 | * |
186 | * barrier(); | 183 | * barrier(); |
187 | * if (pc->lock != seq) | 184 | * } while (pc->lock != seq); |
188 | * goto again; | ||
189 | * | 185 | * |
190 | * NOTE: for obvious reason this only works on self-monitoring | 186 | * NOTE: for obvious reason this only works on self-monitoring |
191 | * processes. | 187 | * processes. |