From: Jan Kara <jack@suse.cz>
Date: Tue, 13 Nov 2007 18:59:33 +0000 (+0100)
Subject: [PATCH] ocfs2: Remove expensive bitmap scanning
X-Git-Tag: v2.6.24-rc4~83^2~3
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5a58c3ef22d6e5b84ff651a7d27ae2cbea9f9870;p=linux-2.6

[PATCH] ocfs2: Remove expensive bitmap scanning

Enable expensive bitmap scanning only if DEBUG option is enabled.
The bitmap scanning quite loads the CPU and on my machine the write
throughput of dd if=/dev/zero of=/ocfs2/file bs=1M count=500 conv=sync
improves from 37 MB/s to 45.4 MB/s in local mode...

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
---

diff --git a/fs/Kconfig b/fs/Kconfig
index 429a002285..635f3e286a 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -459,6 +459,15 @@ config OCFS2_DEBUG_MASKLOG
 	  This option will enlarge your kernel, but it allows debugging of
 	  ocfs2 filesystem issues.
 
+config OCFS2_DEBUG_FS
+	bool "OCFS2 expensive checks"
+	depends on OCFS2_FS
+	default n
+	help
+	  This option will enable expensive consistency checks. Enable
+	  this option for debugging only as it is likely to decrease
+	  performance of the filesystem.
+
 config MINIX_FS
 	tristate "Minix fs support"
 	help
diff --git a/fs/ocfs2/localalloc.c b/fs/ocfs2/localalloc.c
index d272847d5a..58ea88b5af 100644
--- a/fs/ocfs2/localalloc.c
+++ b/fs/ocfs2/localalloc.c
@@ -484,6 +484,7 @@ int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
 
 	alloc = (struct ocfs2_dinode *) osb->local_alloc_bh->b_data;
 
+#ifdef OCFS2_DEBUG_FS
 	if (le32_to_cpu(alloc->id1.bitmap1.i_used) !=
 	    ocfs2_local_alloc_count_bits(alloc)) {
 		ocfs2_error(osb->sb, "local alloc inode %llu says it has "
@@ -494,6 +495,7 @@ int ocfs2_reserve_local_alloc_bits(struct ocfs2_super *osb,
 		status = -EIO;
 		goto bail;
 	}
+#endif
 
 	free_bits = le32_to_cpu(alloc->id1.bitmap1.i_total) -
 		le32_to_cpu(alloc->id1.bitmap1.i_used);
@@ -712,9 +714,8 @@ static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
 	void *bitmap;
 	struct ocfs2_local_alloc *la = OCFS2_LOCAL_ALLOC(alloc);
 
-	mlog_entry("total = %u, COUNT = %u, used = %u\n",
+	mlog_entry("total = %u, used = %u\n",
 		   le32_to_cpu(alloc->id1.bitmap1.i_total),
-		   ocfs2_local_alloc_count_bits(alloc),
 		   le32_to_cpu(alloc->id1.bitmap1.i_used));
 
 	if (!alloc->id1.bitmap1.i_total) {