From 4862fd6047ed02e2726667c54d35f538eecc56aa Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 10 Jul 2011 22:05:08 -0400 Subject: [PATCH] jbd2: remove jbd2_dev_to_name() from jbd2 tracepoints Using function calls in TP_printk causes perf heartburn, so print the MAJOR/MINOR device numbers instead. Signed-off-by: "Theodore Ts'o" --- fs/jbd2/journal.c | 67 ------------------------------------- include/linux/jbd2.h | 6 ---- include/trace/events/jbd2.h | 36 ++++++++++---------- 3 files changed, 19 insertions(+), 90 deletions(-) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 0dfa5b598e68..f24df13adc4e 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -2390,73 +2390,6 @@ static void __exit journal_exit(void) jbd2_journal_destroy_caches(); } -/* - * jbd2_dev_to_name is a utility function used by the jbd2 and ext4 - * tracing infrastructure to map a dev_t to a device name. - * - * The caller should use rcu_read_lock() in order to make sure the - * device name stays valid until its done with it. We use - * rcu_read_lock() as well to make sure we're safe in case the caller - * gets sloppy, and because rcu_read_lock() is cheap and can be safely - * nested. - */ -struct devname_cache { - struct rcu_head rcu; - dev_t device; - char devname[BDEVNAME_SIZE]; -}; -#define CACHE_SIZE_BITS 6 -static struct devname_cache *devcache[1 << CACHE_SIZE_BITS]; -static DEFINE_SPINLOCK(devname_cache_lock); - -static void free_devcache(struct rcu_head *rcu) -{ - kfree(rcu); -} - -const char *jbd2_dev_to_name(dev_t device) -{ - int i = hash_32(device, CACHE_SIZE_BITS); - char *ret; - struct block_device *bd; - static struct devname_cache *new_dev; - - rcu_read_lock(); - if (devcache[i] && devcache[i]->device == device) { - ret = devcache[i]->devname; - rcu_read_unlock(); - return ret; - } - rcu_read_unlock(); - - new_dev = kmalloc(sizeof(struct devname_cache), GFP_KERNEL); - if (!new_dev) - return "NODEV-ALLOCFAILURE"; /* Something non-NULL */ - bd = bdget(device); - spin_lock(&devname_cache_lock); - if (devcache[i]) { - if (devcache[i]->device == device) { - kfree(new_dev); - bdput(bd); - ret = devcache[i]->devname; - spin_unlock(&devname_cache_lock); - return ret; - } - call_rcu(&devcache[i]->rcu, free_devcache); - } - devcache[i] = new_dev; - devcache[i]->device = device; - if (bd) { - bdevname(bd, devcache[i]->devname); - bdput(bd); - } else - __bdevname(device, devcache[i]->devname); - ret = devcache[i]->devname; - spin_unlock(&devname_cache_lock); - return ret; -} -EXPORT_SYMBOL(jbd2_dev_to_name); - MODULE_LICENSE("GPL"); module_init(journal_init); module_exit(journal_exit); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index d087c2e7b2aa..38f307b8c334 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1329,12 +1329,6 @@ extern int jbd_blocks_per_page(struct inode *inode); #define BUFFER_TRACE2(bh, bh2, info) do {} while (0) #define JBUFFER_TRACE(jh, info) do {} while (0) -/* - * jbd2_dev_to_name is a utility function used by the jbd2 and ext4 - * tracing infrastructure to map a dev_t to a device name. - */ -extern const char *jbd2_dev_to_name(dev_t device); - #endif /* __KERNEL__ */ #endif /* _LINUX_JBD2_H */ diff --git a/include/trace/events/jbd2.h b/include/trace/events/jbd2.h index bf16545cc977..75964412ddbb 100644 --- a/include/trace/events/jbd2.h +++ b/include/trace/events/jbd2.h @@ -26,8 +26,8 @@ TRACE_EVENT(jbd2_checkpoint, __entry->result = result; ), - TP_printk("dev %s result %d", - jbd2_dev_to_name(__entry->dev), __entry->result) + TP_printk("dev %d,%d result %d", + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->result) ); DECLARE_EVENT_CLASS(jbd2_commit, @@ -48,9 +48,9 @@ DECLARE_EVENT_CLASS(jbd2_commit, __entry->transaction = commit_transaction->t_tid; ), - TP_printk("dev %s transaction %d sync %d", - jbd2_dev_to_name(__entry->dev), __entry->transaction, - __entry->sync_commit) + TP_printk("dev %d,%d transaction %d sync %d", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->transaction, __entry->sync_commit) ); DEFINE_EVENT(jbd2_commit, jbd2_start_commit, @@ -100,9 +100,9 @@ TRACE_EVENT(jbd2_end_commit, __entry->head = journal->j_tail_sequence; ), - TP_printk("dev %s transaction %d sync %d head %d", - jbd2_dev_to_name(__entry->dev), __entry->transaction, - __entry->sync_commit, __entry->head) + TP_printk("dev %d,%d transaction %d sync %d head %d", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->transaction, __entry->sync_commit, __entry->head) ); TRACE_EVENT(jbd2_submit_inode_data, @@ -120,8 +120,9 @@ TRACE_EVENT(jbd2_submit_inode_data, __entry->ino = inode->i_ino; ), - TP_printk("dev %s ino %lu", - jbd2_dev_to_name(__entry->dev), (unsigned long) __entry->ino) + TP_printk("dev %d,%d ino %lu", + MAJOR(__entry->dev), MINOR(__entry->dev), + (unsigned long) __entry->ino) ); TRACE_EVENT(jbd2_run_stats, @@ -156,9 +157,9 @@ TRACE_EVENT(jbd2_run_stats, __entry->blocks_logged = stats->rs_blocks_logged; ), - TP_printk("dev %s tid %lu wait %u running %u locked %u flushing %u " + TP_printk("dev %d,%d tid %lu wait %u running %u locked %u flushing %u " "logging %u handle_count %u blocks %u blocks_logged %u", - jbd2_dev_to_name(__entry->dev), __entry->tid, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->tid, jiffies_to_msecs(__entry->wait), jiffies_to_msecs(__entry->running), jiffies_to_msecs(__entry->locked), @@ -192,9 +193,9 @@ TRACE_EVENT(jbd2_checkpoint_stats, __entry->dropped = stats->cs_dropped; ), - TP_printk("dev %s tid %lu chp_time %u forced_to_close %u " + TP_printk("dev %d,%d tid %lu chp_time %u forced_to_close %u " "written %u dropped %u", - jbd2_dev_to_name(__entry->dev), __entry->tid, + MAJOR(__entry->dev), MINOR(__entry->dev), __entry->tid, jiffies_to_msecs(__entry->chp_time), __entry->forced_to_close, __entry->written, __entry->dropped) ); @@ -222,9 +223,10 @@ TRACE_EVENT(jbd2_cleanup_journal_tail, __entry->freed = freed; ), - TP_printk("dev %s from %u to %u offset %lu freed %lu", - jbd2_dev_to_name(__entry->dev), __entry->tail_sequence, - __entry->first_tid, __entry->block_nr, __entry->freed) + TP_printk("dev %d,%d from %u to %u offset %lu freed %lu", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->tail_sequence, __entry->first_tid, + __entry->block_nr, __entry->freed) ); #endif /* _TRACE_JBD2_H */ -- 2.20.1