From: Andrew Morton <akpm@osdl.org>
To: busterbcook@yahoo.com, linux-kernel@vger.kernel.org
Subject: Re: pdflush eating a lot of CPU on heavy NFS I/O
Date: Wed, 28 Apr 2004 21:03:02 -0700 [thread overview]
Message-ID: <20040428210302.4431c9c3.akpm@osdl.org> (raw)
In-Reply-To: <20040428210214.31efe911.akpm@osdl.org>
Andrew Morton <akpm@osdl.org> wrote:
>
> Does this fix it?
If not, please try this new debug patch, against -rc3.
diff -puN include/linux/kernel.h~proc-sys-debug include/linux/kernel.h
--- 25/include/linux/kernel.h~proc-sys-debug Tue Apr 27 17:11:39 2004
+++ 25-akpm/include/linux/kernel.h Tue Apr 27 17:11:39 2004
@@ -220,6 +220,8 @@ extern void dump_stack(void);
1; \
})
+extern int proc_sys_debug[8];
+
#endif /* __KERNEL__ */
#define SI_LOAD_SHIFT 16
diff -puN kernel/sysctl.c~proc-sys-debug kernel/sysctl.c
--- 25/kernel/sysctl.c~proc-sys-debug Tue Apr 27 17:11:39 2004
+++ 25-akpm/kernel/sysctl.c Tue Apr 27 17:11:39 2004
@@ -888,7 +888,26 @@ static ctl_table fs_table[] = {
{ .ctl_name = 0 }
};
+int proc_sys_debug[8];
+EXPORT_SYMBOL(proc_sys_debug);
+
static ctl_table debug_table[] = {
+ {1, "0", &proc_sys_debug[0], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {2, "1", &proc_sys_debug[1], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {3, "2", &proc_sys_debug[2], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {4, "3", &proc_sys_debug[3], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {5, "4", &proc_sys_debug[4], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {6, "5", &proc_sys_debug[5], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {7, "6", &proc_sys_debug[6], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
+ {8, "7", &proc_sys_debug[7], sizeof(int), 0644, NULL,
+ &proc_dointvec_minmax, &sysctl_intvec, NULL, NULL, NULL},
{ .ctl_name = 0 }
};
_
---
25-akpm/fs/fs-writeback.c | 32 ++++++++++++++++++++++++++++++++
25-akpm/fs/mpage.c | 6 ++++++
2 files changed, 38 insertions(+)
diff -puN fs/fs-writeback.c~pdflush-debug fs/fs-writeback.c
--- 25/fs/fs-writeback.c~pdflush-debug 2004-04-28 20:52:05.820437744 -0700
+++ 25-akpm/fs/fs-writeback.c 2004-04-28 21:01:05.062460496 -0700
@@ -152,7 +152,23 @@ __sync_single_inode(struct inode *inode,
spin_unlock(&inode_lock);
+ if (proc_sys_debug[0]) {
+ printk("%s: writepages in nr_pages:%lu nr_to_write:%ld"
+ " pages_skipped:%ld en:%d\n",
+ __FUNCTION__,
+ mapping->nrpages, wbc->nr_to_write,
+ wbc->pages_skipped,
+ wbc->encountered_congestion);
+ }
ret = do_writepages(mapping, wbc);
+ if (proc_sys_debug[0]) {
+ printk("%s: writepages out nr_pages:%lu nr_to_write:%ld"
+ " pages_skipped:%ld en:%d\n",
+ __FUNCTION__,
+ mapping->nrpages, wbc->nr_to_write,
+ wbc->pages_skipped,
+ wbc->encountered_congestion);
+ }
/* Don't write the inode if only I_DIRTY_PAGES was set */
if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC))
@@ -180,6 +196,8 @@ __sync_single_inode(struct inode *inode,
* writeout as soon as the queue becomes
* uncongested.
*/
+ if (proc_sys_debug[0])
+ printk("%s:%d\n", __FILE__, __LINE__);
inode->i_state |= I_DIRTY_PAGES;
} else {
/*
@@ -192,22 +210,30 @@ __sync_single_inode(struct inode *inode,
inode->i_state |= I_DIRTY_PAGES;
inode->dirtied_when = jiffies;
list_move(&inode->i_list, &sb->s_dirty);
+ if (proc_sys_debug[0])
+ printk("%s:%d\n", __FILE__, __LINE__);
}
} else if (inode->i_state & I_DIRTY) {
/*
* Someone redirtied the inode while were writing back
* the pages: nothing to do.
*/
+ if (proc_sys_debug[0])
+ printk("%s:%d\n", __FILE__, __LINE__);
} else if (atomic_read(&inode->i_count)) {
/*
* The inode is clean, inuse
*/
list_move(&inode->i_list, &inode_in_use);
+ if (proc_sys_debug[0])
+ printk("%s:%d\n", __FILE__, __LINE__);
} else {
/*
* The inode is clean, unused
*/
list_move(&inode->i_list, &inode_unused);
+ if (proc_sys_debug[0])
+ printk("%s:%d\n", __FILE__, __LINE__);
}
}
wake_up_inode(inode);
@@ -328,6 +354,9 @@ sync_sb_inodes(struct super_block *sb, s
if (current_is_pdflush() && !writeback_acquire(bdi))
break;
+ if (proc_sys_debug[0]) {
+ printk("%s: write inode %p\n", __FUNCTION__, inode);
+ }
BUG_ON(inode->i_state & I_FREEING);
__iget(inode);
pages_skipped = wbc->pages_skipped;
@@ -384,6 +413,9 @@ writeback_inodes(struct writeback_contro
for (; sb != sb_entry(&super_blocks); sb = sb_entry(sb->s_list.prev)) {
if (!list_empty(&sb->s_dirty) || !list_empty(&sb->s_io)) {
spin_unlock(&sb_lock);
+ if (proc_sys_debug[0]) {
+ printk("%s: sync sb %p\n", __FUNCTION__, sb);
+ }
sync_sb_inodes(sb, wbc);
spin_lock(&sb_lock);
}
diff -puN fs/mpage.c~pdflush-debug fs/mpage.c
--- 25/fs/mpage.c~pdflush-debug 2004-04-28 20:52:05.821437592 -0700
+++ 25-akpm/fs/mpage.c 2004-04-28 20:52:05.825436984 -0700
@@ -658,6 +658,12 @@ retry:
if (writepage) {
ret = (*writepage)(page, wbc);
if (ret) {
+ if (proc_sys_debug[0]) {
+ printk("%s: writepage "
+ "returned %d\n",
+ __FUNCTION__,
+ ret);
+ }
if (ret == -ENOSPC)
set_bit(AS_ENOSPC,
&mapping->flags);
_
next prev parent reply other threads:[~2004-04-29 4:04 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-04-28 5:18 pdflush eating a lot of CPU on heavy NFS I/O Brent Cook
2004-04-28 6:02 ` Andrew Morton
2004-04-28 7:29 ` Phy Prabab
2004-04-28 10:18 ` Sven Geggus
2004-04-28 13:50 ` Brent Cook
2004-04-28 19:48 ` Andrew Morton
2004-04-28 20:12 ` Brent Cook
2004-04-28 20:39 ` Brent Cook
2004-04-28 21:19 ` Trond Myklebust
2004-04-29 3:55 ` Brent Cook
2004-04-29 4:21 ` Trond Myklebust
2004-04-29 4:42 ` Andrew Morton
2004-04-29 1:24 ` Andrew Morton
2004-04-29 3:53 ` Brent Cook
2004-04-29 4:02 ` Andrew Morton
2004-04-29 4:03 ` Andrew Morton [this message]
2004-04-29 4:37 ` Brent Cook
2004-04-29 4:47 ` Andrew Morton
2004-04-29 5:29 ` Andrew Morton
2004-04-29 13:19 ` Brent Cook
2004-04-29 3:54 ` Andrew Morton
2004-04-28 6:06 ` Brett E.
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