From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from toip3.srvr.bell.ca ([209.226.175.86]) by tomts22-srv.bellnexxia.net (InterMail vM.5.01.06.13 201-253-122-130-113-20050324) with ESMTP id <20080716143720.BRAN1527.tomts22-srv.bellnexxia.net@toip3.srvr.bell.ca> for ; Wed, 16 Jul 2008 10:37:20 -0400 Date: Wed, 16 Jul 2008 10:37:19 -0400 From: Mathieu Desnoyers Subject: Re: [patch 09/17] LTTng instrumentation - filemap Message-ID: <20080716143719.GF24546@Krystal> References: <20080715222604.331269462@polymtl.ca> <20080715222748.002421557@polymtl.ca> <1216197334.5232.24.camel@twins> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <1216197334.5232.24.camel@twins> Sender: owner-linux-mm@kvack.org Return-Path: To: Peter Zijlstra Cc: akpm@linux-foundation.org, Ingo Molnar , linux-kernel@vger.kernel.org, Masami Hiramatsu , linux-mm@kvack.org, Dave Hansen , "Frank Ch. Eigler" , Hideo AOKI , Takashi Nishiie , Steven Rostedt , Eduard - Gabriel Munteanu List-ID: * Peter Zijlstra (peterz@infradead.org) wrote: > On Tue, 2008-07-15 at 18:26 -0400, Mathieu Desnoyers wrote: > > plain text document attachment (lttng-instrumentation-filemap.patch) > > Instrumentation of waits caused by memory accesses on mmap regions. > > > > Those tracepoints are used by LTTng. > > > > About the performance impact of tracepoints (which is comparable to markers), > > even without immediate values optimizations, tests done by Hideo Aoki on ia64 > > show no regression. His test case was using hackbench on a kernel where > > scheduler instrumentation (about 5 events in code scheduler code) was added. > > See the "Tracepoints" patch header for performance result detail. > > > > Signed-off-by: Mathieu Desnoyers > > CC: linux-mm@kvack.org > > CC: Dave Hansen > > CC: Masami Hiramatsu > > CC: 'Peter Zijlstra' > > CC: "Frank Ch. Eigler" > > CC: 'Ingo Molnar' > > CC: 'Hideo AOKI' > > CC: Takashi Nishiie > > CC: 'Steven Rostedt' > > CC: Eduard - Gabriel Munteanu > > --- > > include/trace/filemap.h | 13 +++++++++++++ > > mm/filemap.c | 3 +++ > > 2 files changed, 16 insertions(+) > > > > Index: linux-2.6-lttng/mm/filemap.c > > =================================================================== > > --- linux-2.6-lttng.orig/mm/filemap.c 2008-07-15 14:51:50.000000000 -0400 > > +++ linux-2.6-lttng/mm/filemap.c 2008-07-15 15:14:46.000000000 -0400 > > @@ -33,6 +33,7 @@ > > #include > > #include /* for BUG_ON(!in_atomic()) only */ > > #include > > +#include > > #include "internal.h" > > > > /* > > @@ -541,9 +542,11 @@ void wait_on_page_bit(struct page *page, > > { > > DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); > > > > + trace_filemap_wait_start(page, bit_nr); > > if (test_bit(bit_nr, &page->flags)) > > __wait_on_bit(page_waitqueue(page), &wait, sync_page, > > TASK_UNINTERRUPTIBLE); > > + trace_filemap_wait_end(page, bit_nr); > > } > > EXPORT_SYMBOL(wait_on_page_bit); > > I don't like the trace_filemap_wait_* naming.. > Me neither :) > trace_wait_on_page_* might make more sense > Yep, agreed, Mathieu > > Index: linux-2.6-lttng/include/trace/filemap.h > > =================================================================== > > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > > +++ linux-2.6-lttng/include/trace/filemap.h 2008-07-15 15:14:46.000000000 -0400 > > @@ -0,0 +1,13 @@ > > +#ifndef _TRACE_FILEMAP_H > > +#define _TRACE_FILEMAP_H > > + > > +#include > > + > > +DEFINE_TRACE(filemap_wait_start, > > + TPPROTO(struct page *page, int bit_nr), > > + TPARGS(page, bit_nr)); > > +DEFINE_TRACE(filemap_wait_end, > > + TPPROTO(struct page *page, int bit_nr), > > + TPARGS(page, bit_nr)); > > + > > +#endif > > > -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org