From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757040AbZEFEZq (ORCPT ); Wed, 6 May 2009 00:25:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752471AbZEFEXk (ORCPT ); Wed, 6 May 2009 00:23:40 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:56422 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751005AbZEFEXe (ORCPT ); Wed, 6 May 2009 00:23:34 -0400 Message-Id: <20090506042334.036756181@goodmis.org> References: <20090506042101.231470089@goodmis.org> User-Agent: quilt/0.46-1 Date: Wed, 06 May 2009 00:21:07 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker Subject: [PATCH 06/11] ring-buffer: have read page swap increment counter with page entries Content-Disposition: inline; filename=0006-ring-buffer-have-read-page-swap-increment-counter-w.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Steven Rostedt In the swap page ring buffer code that is used by the ftrace splice code, we scan the page to increment the counter of entries read. With the number of entries already in the page we simply need to add it. [ Impact: speed up reading page from ring buffer ] Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 28 +++------------------------- 1 files changed, 3 insertions(+), 25 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 342eacc..9e42a74 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2785,28 +2785,6 @@ out: } EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu); -static void rb_remove_entries(struct ring_buffer_per_cpu *cpu_buffer, - struct buffer_data_page *bpage, - unsigned int offset) -{ - struct ring_buffer_event *event; - unsigned long head; - - __raw_spin_lock(&cpu_buffer->lock); - for (head = offset; head < local_read(&bpage->commit); - head += rb_event_length(event)) { - - event = __rb_data_page_index(bpage, head); - if (RB_WARN_ON(cpu_buffer, rb_null_event(event))) - return; - /* Only count data entries */ - if (event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX) - continue; - cpu_buffer->read++; - } - __raw_spin_unlock(&cpu_buffer->lock); -} - /** * ring_buffer_alloc_read_page - allocate a page to read from buffer * @buffer: the buffer to allocate for. @@ -2977,6 +2955,9 @@ int ring_buffer_read_page(struct ring_buffer *buffer, /* we copied everything to the beginning */ read = 0; } else { + /* update the entry counter */ + cpu_buffer->read += local_read(&reader->entries); + /* swap the pages */ rb_init_page(bpage); bpage = reader->page; @@ -2985,9 +2966,6 @@ int ring_buffer_read_page(struct ring_buffer *buffer, local_set(&reader->entries, 0); reader->read = 0; *data_page = bpage; - - /* update the entry counter */ - rb_remove_entries(cpu_buffer, bpage, read); } ret = read; -- 1.6.2.4 --