aboutsummaryrefslogtreecommitdiff
path: root/include/trace
diff options
context:
space:
mode:
authorEric Gouriou <egouriou@google.com>2011-10-27 11:43:23 -0400
committerTheodore Ts'o <tytso@mit.edu>2011-10-27 11:43:23 -0400
commit6f91bc5fda82d2c49b4f7fb29424cf6a3c7574bc (patch)
treee5670070f007c4ad5300e93a4e36fa9a802e2bd9 /include/trace
parent446066724c3629664e29942a00b0aee0d6b1663a (diff)
downloadlinux-linaro-stable-6f91bc5fda82d2c49b4f7fb29424cf6a3c7574bc.tar.gz
ext4: optimize ext4_ext_convert_to_initialized()
This patch introduces a fast path in ext4_ext_convert_to_initialized() for the case when the conversion can be performed by transferring the newly initialized blocks from the uninitialized extent into an adjacent initialized extent. Doing so removes the expensive invocations of memmove() which occur during extent insertion and the subsequent merge. In practice this should be the common case for clients performing append writes into files pre-allocated via fallocate(FALLOC_FL_KEEP_SIZE). In such a workload performed via direct IO and when using a suboptimal implementation of memmove() (x86_64 prior to the 2.6.39 rewrite), this patch reduces kernel CPU consumption by 32%. Two new trace points are added to ext4_ext_convert_to_initialized() to offer visibility into its operations. No exit trace point has been added due to the multiplicity of return points. This can be revisited once the upstream cleanup is backported. Signed-off-by: Eric Gouriou <egouriou@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'include/trace')
-rw-r--r--include/trace/events/ext4.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index c9a341e385a3..748ff7cbe555 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -9,6 +9,7 @@
struct ext4_allocation_context;
struct ext4_allocation_request;
+struct ext4_extent;
struct ext4_prealloc_space;
struct ext4_inode_info;
struct mpage_da_data;
@@ -1394,6 +1395,87 @@ DEFINE_EVENT(ext4__truncate, ext4_truncate_exit,
TP_ARGS(inode)
);
+/* 'ux' is the uninitialized extent. */
+TRACE_EVENT(ext4_ext_convert_to_initialized_enter,
+ TP_PROTO(struct inode *inode, struct ext4_map_blocks *map,
+ struct ext4_extent *ux),
+
+ TP_ARGS(inode, map, ux),
+
+ TP_STRUCT__entry(
+ __field( ino_t, ino )
+ __field( dev_t, dev )
+ __field( ext4_lblk_t, m_lblk )
+ __field( unsigned, m_len )
+ __field( ext4_lblk_t, u_lblk )
+ __field( unsigned, u_len )
+ __field( ext4_fsblk_t, u_pblk )
+ ),
+
+ TP_fast_assign(
+ __entry->ino = inode->i_ino;
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->m_lblk = map->m_lblk;
+ __entry->m_len = map->m_len;
+ __entry->u_lblk = le32_to_cpu(ux->ee_block);
+ __entry->u_len = ext4_ext_get_actual_len(ux);
+ __entry->u_pblk = ext4_ext_pblock(ux);
+ ),
+
+ TP_printk("dev %d,%d ino %lu m_lblk %u m_len %u u_lblk %u u_len %u "
+ "u_pblk %llu",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ (unsigned long) __entry->ino,
+ __entry->m_lblk, __entry->m_len,
+ __entry->u_lblk, __entry->u_len, __entry->u_pblk)
+);
+
+/*
+ * 'ux' is the uninitialized extent.
+ * 'ix' is the initialized extent to which blocks are transferred.
+ */
+TRACE_EVENT(ext4_ext_convert_to_initialized_fastpath,
+ TP_PROTO(struct inode *inode, struct ext4_map_blocks *map,
+ struct ext4_extent *ux, struct ext4_extent *ix),
+
+ TP_ARGS(inode, map, ux, ix),
+
+ TP_STRUCT__entry(
+ __field( ino_t, ino )
+ __field( dev_t, dev )
+ __field( ext4_lblk_t, m_lblk )
+ __field( unsigned, m_len )
+ __field( ext4_lblk_t, u_lblk )
+ __field( unsigned, u_len )
+ __field( ext4_fsblk_t, u_pblk )
+ __field( ext4_lblk_t, i_lblk )
+ __field( unsigned, i_len )
+ __field( ext4_fsblk_t, i_pblk )
+ ),
+
+ TP_fast_assign(
+ __entry->ino = inode->i_ino;
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->m_lblk = map->m_lblk;
+ __entry->m_len = map->m_len;
+ __entry->u_lblk = le32_to_cpu(ux->ee_block);
+ __entry->u_len = ext4_ext_get_actual_len(ux);
+ __entry->u_pblk = ext4_ext_pblock(ux);
+ __entry->i_lblk = le32_to_cpu(ix->ee_block);
+ __entry->i_len = ext4_ext_get_actual_len(ix);
+ __entry->i_pblk = ext4_ext_pblock(ix);
+ ),
+
+ TP_printk("dev %d,%d ino %lu m_lblk %u m_len %u "
+ "u_lblk %u u_len %u u_pblk %llu "
+ "i_lblk %u i_len %u i_pblk %llu ",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ (unsigned long) __entry->ino,
+ __entry->m_lblk, __entry->m_len,
+ __entry->u_lblk, __entry->u_len, __entry->u_pblk,
+ __entry->i_lblk, __entry->i_len, __entry->i_pblk)
+);
+
DECLARE_EVENT_CLASS(ext4__map_blocks_enter,
TP_PROTO(struct inode *inode, ext4_lblk_t lblk,
unsigned int len, unsigned int flags),