From: Steven Rostedt Date: Thu, 11 Jun 2009 13:29:58 +0000 (-0400) Subject: ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=22f470f8daea64bc03be1fe30c8c5df382295386;p=deliverable%2Flinux.git ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index The index of the event is found by masking PAGE_MASK to it and subtracting the header size. Currently the header size is calculate by PAGE_SIZE - BUF_PAGE_SIZE, when we already have a macro BUF_PAGE_HDR_SIZE to define it. If we want to change BUF_PAGE_SIZE to something less than filling the rest of the page (this is done for debugging), then we break the algorithm to find the index. Signed-off-by: Steven Rostedt --- diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index ed3559944fcf..6b17a11e42a2 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1013,7 +1013,7 @@ rb_event_index(struct ring_buffer_event *event) { unsigned long addr = (unsigned long)event; - return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); + return (addr & ~PAGE_MASK) - BUF_PAGE_HDR_SIZE; } static inline int