The following commit has been merged into the perf/core branch of tip: Commit-ID: 539f7c26b41d4ed7d88dd9756de3966ae7ca07b4 Gitweb: https://git.kernel.org/tip/539f7c26b41d4ed7d88dd9756de3966ae7ca07b4 Author: Alexander Shishkin <[email protected]> AuthorDate: Wed, 21 Aug 2019 15:47:24 +03:00 Committer: Ingo Molnar <[email protected]> CommitterDate: Mon, 26 Aug 2019 12:00:13 +02:00
perf/x86/intel/pt: Use pointer arithmetics instead in ToPA entry calculation Currently, pt_buffer_reset_offsets() calculates the current ToPA entry by casting pointers to addresses and performing ungainly subtractions and divisions instead of a simpler pointer arithmetic, which would be perfectly applicable in that case. Fix that. Signed-off-by: Alexander Shishkin <[email protected]> Cc: Arnaldo Carvalho de Melo <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vince Weaver <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/events/intel/pt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c index f269875..188d45f 100644 --- a/arch/x86/events/intel/pt.c +++ b/arch/x86/events/intel/pt.c @@ -1030,8 +1030,7 @@ static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head) pg = pt_topa_next_entry(buf, pg); buf->cur = (struct topa *)((unsigned long)buf->topa_index[pg] & PAGE_MASK); - buf->cur_idx = ((unsigned long)buf->topa_index[pg] - - (unsigned long)buf->cur) / sizeof(struct topa_entry); + buf->cur_idx = buf->topa_index[pg] - TOPA_ENTRY(buf->cur, 0); buf->output_off = head & (pt_buffer_region_size(buf) - 1); local64_set(&buf->head, head);
