Change the callchain context entries to u16, so as to gain some space. Signed-off-by: Peter Zijlstra --- include/linux/perf_counter.h | 4 ++-- kernel/perf_counter.c | 6 ++---- 2 files changed, 4 insertions(+), 6 deletions(-) Index: linux-2.6/include/linux/perf_counter.h =================================================================== --- linux-2.6.orig/include/linux/perf_counter.h +++ linux-2.6/include/linux/perf_counter.h @@ -507,10 +507,10 @@ extern void perf_counter_mmap(unsigned l extern void perf_counter_munmap(unsigned long addr, unsigned long len, unsigned long pgoff, struct file *file); -#define MAX_STACK_DEPTH 254 +#define MAX_STACK_DEPTH 255 struct perf_callchain_entry { - u32 nr, hv, kernel, user; + u16 nr, hv, kernel, user; u64 ip[MAX_STACK_DEPTH]; }; Index: linux-2.6/kernel/perf_counter.c =================================================================== --- linux-2.6.orig/kernel/perf_counter.c +++ linux-2.6/kernel/perf_counter.c @@ -1657,9 +1657,7 @@ void perf_counter_do_pending(void) * Callchain support -- arch specific */ -struct perf_callchain_entry * -__attribute__((weak)) -perf_callchain(struct pt_regs *regs) +__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs) { return NULL; } @@ -1819,7 +1817,7 @@ void perf_counter_output(struct perf_cou callchain = perf_callchain(regs); if (callchain) { - callchain_size = (2 + callchain->nr) * sizeof(u64); + callchain_size = (1 + callchain->nr) * sizeof(u64); header.type |= __PERF_EVENT_CALLCHAIN; header.size += callchain_size; -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/