From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755947Ab1K2PWe (ORCPT ); Tue, 29 Nov 2011 10:22:34 -0500 Received: from cantor2.suse.de ([195.135.220.15]:40474 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754796Ab1K2PWa (ORCPT ); Tue, 29 Nov 2011 10:22:30 -0500 Date: Tue, 29 Nov 2011 16:22:28 +0100 From: Jan Kara To: Wu Fengguang Cc: Andrew Morton , Andi Kleen , Ingo Molnar , Jens Axboe , Steven Rostedt , Peter Zijlstra , Rik van Riel , Linux Memory Management List , linux-fsdevel@vger.kernel.org, LKML Subject: Re: [PATCH 7/9] readahead: add vfs/readahead tracing event Message-ID: <20111129152228.GO5635@quack.suse.cz> References: <20111129130900.628549879@intel.com> <20111129131456.797240894@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20111129131456.797240894@intel.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 29-11-11 21:09:07, Wu Fengguang wrote: > This is very useful for verifying whether the readahead algorithms are > working to the expectation. > > Example output: > > # echo 1 > /debug/tracing/events/vfs/readahead/enable > # cp test-file /dev/null > # cat /debug/tracing/trace # trimmed output > readahead-initial(dev=0:15, ino=100177, req=0+2, ra=0+4-2, async=0) = 4 > readahead-subsequent(dev=0:15, ino=100177, req=2+2, ra=4+8-8, async=1) = 8 > readahead-subsequent(dev=0:15, ino=100177, req=4+2, ra=12+16-16, async=1) = 16 > readahead-subsequent(dev=0:15, ino=100177, req=12+2, ra=28+32-32, async=1) = 32 > readahead-subsequent(dev=0:15, ino=100177, req=28+2, ra=60+60-60, async=1) = 24 > readahead-subsequent(dev=0:15, ino=100177, req=60+2, ra=120+60-60, async=1) = 0 > > CC: Ingo Molnar > CC: Jens Axboe > CC: Steven Rostedt > CC: Peter Zijlstra > Acked-by: Rik van Riel > Signed-off-by: Wu Fengguang Looks OK. Acked-by: Jan Kara Honza > --- > include/trace/events/vfs.h | 64 +++++++++++++++++++++++++++++++++++ > mm/readahead.c | 5 ++ > 2 files changed, 69 insertions(+) > > --- /dev/null 1970-01-01 00:00:00.000000000 +0000 > +++ linux-next/include/trace/events/vfs.h 2011-11-29 20:58:59.000000000 +0800 > @@ -0,0 +1,64 @@ > +#undef TRACE_SYSTEM > +#define TRACE_SYSTEM vfs > + > +#if !defined(_TRACE_VFS_H) || defined(TRACE_HEADER_MULTI_READ) > +#define _TRACE_VFS_H > + > +#include > + > +TRACE_EVENT(readahead, > + TP_PROTO(struct address_space *mapping, > + pgoff_t offset, > + unsigned long req_size, > + enum readahead_pattern pattern, > + pgoff_t start, > + unsigned long size, > + unsigned long async_size, > + unsigned int actual), > + > + TP_ARGS(mapping, offset, req_size, pattern, start, size, async_size, > + actual), > + > + TP_STRUCT__entry( > + __field( dev_t, dev ) > + __field( ino_t, ino ) > + __field( pgoff_t, offset ) > + __field( unsigned long, req_size ) > + __field( unsigned int, pattern ) > + __field( pgoff_t, start ) > + __field( unsigned int, size ) > + __field( unsigned int, async_size ) > + __field( unsigned int, actual ) > + ), > + > + TP_fast_assign( > + __entry->dev = mapping->host->i_sb->s_dev; > + __entry->ino = mapping->host->i_ino; > + __entry->offset = offset; > + __entry->req_size = req_size; > + __entry->pattern = pattern; > + __entry->start = start; > + __entry->size = size; > + __entry->async_size = async_size; > + __entry->actual = actual; > + ), > + > + TP_printk("readahead-%s(dev=%d:%d, ino=%lu, " > + "req=%lu+%lu, ra=%lu+%d-%d, async=%d) = %d", > + ra_pattern_names[__entry->pattern], > + MAJOR(__entry->dev), > + MINOR(__entry->dev), > + __entry->ino, > + __entry->offset, > + __entry->req_size, > + __entry->start, > + __entry->size, > + __entry->async_size, > + __entry->start > __entry->offset, > + __entry->actual) > +); > + > +#endif /* _TRACE_VFS_H */ > + > +/* This part must be outside protection */ > +#include > --- linux-next.orig/mm/readahead.c 2011-11-29 20:58:53.000000000 +0800 > +++ linux-next/mm/readahead.c 2011-11-29 20:59:20.000000000 +0800 > @@ -29,6 +29,9 @@ static const char * const ra_pattern_nam > [RA_PATTERN_ALL] = "all", > }; > > +#define CREATE_TRACE_POINTS > +#include > + > /* > * Initialise a struct file's readahead state. Assumes that the caller has > * memset *ra to zero. > @@ -215,6 +218,8 @@ static inline void readahead_event(struc > for_mmap, for_metadata, > pattern, start, size, async_size, actual); > #endif > + trace_readahead(mapping, offset, req_size, > + pattern, start, size, async_size, actual); > } > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Jan Kara SUSE Labs, CR