From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755463Ab3BAPiJ (ORCPT ); Fri, 1 Feb 2013 10:38:09 -0500 Received: from mail-pa0-f54.google.com ([209.85.220.54]:36430 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751444Ab3BAPiH (ORCPT ); Fri, 1 Feb 2013 10:38:07 -0500 From: chenggang.qin@gmail.com To: linux-kernel@vger.kernel.org Cc: chenggang , Steven Rostedt , Frederic Weisbecker , Ingo Molnar Subject: [PATCH] Tracepoint: Add 'file name' as a parameter of tracepoint events ext4:ext4_direct_IO_enter&ext4:ext4_direct_IO_exit Date: Fri, 1 Feb 2013 23:37:38 +0800 Message-Id: <510be15d.29bf440a.56c6.ffffb82e@mx.google.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: chenggang Yesterday, I implemented these tracepoint events in VFS subsystem. It is not a good idea. Now, I modified two existing tracepoint events in ext4 subsystem to implement the same function. Many database systems use their own page cache subsystems and use the direct IO to access the disks. Sometimes, the system engineers want to know the misses rate of the database system's page cache. They also require to know what files are accessed by the target processes with the direct IO method. These requirements can be satisfied by recording the database's file access behavior through the way of direct IO. So, we add 'file name' as a parameter of tracepoint events: ext4:ext4_direct_IO_enter & ext4:ext4_direct_IO_exit. Then, we will extend the perf or blktrace's function to use these tracepoint events. Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Ingo Molnar Signed-off-by: Chenggang Qin --- fs/ext4/inode.c | 7 +++++-- include/trace/events/ext4.h | 22 ++++++++++++++-------- 2 files changed, 19 insertions(+), 10 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index cbfe13b..92a379f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3202,6 +3202,7 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; ssize_t ret; + const unsigned char *fname; /* * If we are doing data journalling we don't support O_DIRECT @@ -3213,13 +3214,15 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, if (ext4_has_inline_data(inode)) return 0; - trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw); + fname = file->f_path.dentry->d_name.name; + trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw, + fname); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs); else ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs); trace_ext4_direct_IO_exit(inode, offset, - iov_length(iov, nr_segs), rw, ret); + iov_length(iov, nr_segs), rw, ret, fname); return ret; } diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h index 7e8c36b..532bbb4 100644 --- a/include/trace/events/ext4.h +++ b/include/trace/events/ext4.h @@ -1211,9 +1211,10 @@ DEFINE_EVENT(ext4__bitmap_load, ext4_load_inode_bitmap, ); TRACE_EVENT(ext4_direct_IO_enter, - TP_PROTO(struct inode *inode, loff_t offset, unsigned long len, int rw), + TP_PROTO(struct inode *inode, loff_t offset, unsigned long len, int rw, + const unsigned char *fname), - TP_ARGS(inode, offset, len, rw), + TP_ARGS(inode, offset, len, rw, fname), TP_STRUCT__entry( __field( dev_t, dev ) @@ -1221,6 +1222,7 @@ TRACE_EVENT(ext4_direct_IO_enter, __field( loff_t, pos ) __field( unsigned long, len ) __field( int, rw ) + __string( fname, fname ) ), TP_fast_assign( @@ -1229,19 +1231,20 @@ TRACE_EVENT(ext4_direct_IO_enter, __entry->pos = offset; __entry->len = len; __entry->rw = rw; + __assign_str(fname, fname); ), - TP_printk("dev %d,%d ino %lu pos %lld len %lu rw %d", + TP_printk("dev %d,%d ino %lu pos %lld len %lu rw %d fname %s", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long) __entry->ino, - __entry->pos, __entry->len, __entry->rw) + __entry->pos, __entry->len, __entry->rw, __get_str(fname)) ); TRACE_EVENT(ext4_direct_IO_exit, TP_PROTO(struct inode *inode, loff_t offset, unsigned long len, - int rw, int ret), + int rw, int ret, const unsigned char *fname), - TP_ARGS(inode, offset, len, rw, ret), + TP_ARGS(inode, offset, len, rw, ret, fname), TP_STRUCT__entry( __field( dev_t, dev ) @@ -1250,6 +1253,7 @@ TRACE_EVENT(ext4_direct_IO_exit, __field( unsigned long, len ) __field( int, rw ) __field( int, ret ) + __string( fname, fname ) ), TP_fast_assign( @@ -1259,13 +1263,15 @@ TRACE_EVENT(ext4_direct_IO_exit, __entry->len = len; __entry->rw = rw; __entry->ret = ret; + __assign_str(fname, fname); ), - TP_printk("dev %d,%d ino %lu pos %lld len %lu rw %d ret %d", + TP_printk("dev %d,%d ino %lu pos %lld len %lu rw %d ret %d fname %s", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long) __entry->ino, __entry->pos, __entry->len, - __entry->rw, __entry->ret) + __entry->rw, __entry->ret, + __get_str(fname)) ); TRACE_EVENT(ext4_fallocate_enter, -- 1.7.9.5