From 9a8ff578fb430a8816dfbc73c77e5e09c6d9c343 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Tue, 29 Jul 2008 18:29:18 -0700 Subject: [PATCH] ocfs2: track local alloc state via debugfs A per-mount debugfs file, "local_alloc" is created which when read will expose live state of the nodes local alloc file. Performance impact is minimal, only a bit of memory overhead per mount point. Still, the code is hidden behind CONFIG_OCFS2_FS_STATS. This feature will help us debug local alloc performance problems on a live system. Signed-off-by: Mark Fasheh --- fs/ocfs2/localalloc.c | 87 +++++++++++++++++++++++++++++++++++++++++++ fs/ocfs2/ocfs2.h | 5 +++ 2 files changed, 92 insertions(+) diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c index f71658adddb5..b889f10d8090 100644 --- a/fs/ocfs2/localalloc.c +++ b/fs/ocfs2/localalloc.c @@ -28,6 +28,7 @@ #include #include #include +#include #define MLOG_MASK_PREFIX ML_DISK_ALLOC #include @@ -73,6 +74,85 @@ static int ocfs2_local_alloc_new_window(struct ocfs2_super *osb, static int ocfs2_local_alloc_slide_window(struct ocfs2_super *osb, struct inode *local_alloc_inode); +#ifdef CONFIG_OCFS2_FS_STATS + +DEFINE_MUTEX(la_debug_mutex); + +static int ocfs2_la_debug_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +#define LA_DEBUG_BUF_SZ PAGE_CACHE_SIZE +#define LA_DEBUG_VER 1 +static ssize_t ocfs2_la_debug_read(struct file *file, char __user *userbuf, + size_t count, loff_t *ppos) +{ + struct ocfs2_super *osb = file->private_data; + int written, ret; + char *buf = osb->local_alloc_debug_buf; + + mutex_lock(&la_debug_mutex); + memset(buf, 0, LA_DEBUG_BUF_SZ); + + written = snprintf(buf, LA_DEBUG_BUF_SZ, + "0x%x\t0x%llx\t%u\t%u\t0x%x\n", + LA_DEBUG_VER, + (unsigned long long)osb->la_last_gd, + osb->local_alloc_default_bits, + osb->local_alloc_bits, osb->local_alloc_state); + + ret = simple_read_from_buffer(userbuf, count, ppos, buf, written); + + mutex_unlock(&la_debug_mutex); + return ret; +} + +static const struct file_operations ocfs2_la_debug_fops = { + .open = ocfs2_la_debug_open, + .read = ocfs2_la_debug_read, +}; + +static void ocfs2_init_la_debug(struct ocfs2_super *osb) +{ + osb->local_alloc_debug_buf = kmalloc(LA_DEBUG_BUF_SZ, GFP_NOFS); + if (!osb->local_alloc_debug_buf) + return; + + osb->local_alloc_debug = debugfs_create_file("local_alloc_stats", + S_IFREG|S_IRUSR, + osb->osb_debug_root, + osb, + &ocfs2_la_debug_fops); + if (!osb->local_alloc_debug) { + kfree(osb->local_alloc_debug_buf); + osb->local_alloc_debug_buf = NULL; + } +} + +static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb) +{ + if (osb->local_alloc_debug) + debugfs_remove(osb->local_alloc_debug); + + if (osb->local_alloc_debug_buf) + kfree(osb->local_alloc_debug_buf); + + osb->local_alloc_debug_buf = NULL; + osb->local_alloc_debug = NULL; +} +#else /* CONFIG_OCFS2_FS_STATS */ +static void ocfs2_init_la_debug(struct ocfs2_super *osb) +{ + return; +} +static void ocfs2_shutdown_la_debug(struct ocfs2_super *osb) +{ + return; +} +#endif + static inline int ocfs2_la_state_enabled(struct ocfs2_super *osb) { return (osb->local_alloc_state == OCFS2_LA_THROTTLED || @@ -146,6 +226,8 @@ int ocfs2_load_local_alloc(struct ocfs2_super *osb) mlog_entry_void(); + ocfs2_init_la_debug(osb); + if (osb->local_alloc_bits == 0) goto bail; @@ -218,6 +300,9 @@ bail: if (inode) iput(inode); + if (status < 0) + ocfs2_shutdown_la_debug(osb); + mlog(0, "Local alloc window bits = %d\n", osb->local_alloc_bits); mlog_exit(status); @@ -247,6 +332,8 @@ void ocfs2_shutdown_local_alloc(struct ocfs2_super *osb) cancel_delayed_work(&osb->la_enable_wq); flush_workqueue(ocfs2_wq); + ocfs2_shutdown_la_debug(osb); + if (osb->local_alloc_state == OCFS2_LA_UNUSED) goto out; diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h index 4d6e200a4843..128279986d65 100644 --- a/fs/ocfs2/ocfs2.h +++ b/fs/ocfs2/ocfs2.h @@ -272,6 +272,11 @@ struct ocfs2_super u64 la_last_gd; +#ifdef CONFIG_OCFS2_FS_STATS + struct dentry *local_alloc_debug; + char *local_alloc_debug_buf; +#endif + /* Next two fields are for local node slot recovery during * mount. */ int dirty; -- 2.20.1