Took the instrumentation from "ext4: Add markers for better debuggability" and moved it to tracepoints. Signed-off-by: Mathieu Desnoyers CC: Theodore Ts'o CC: Stephen C. Tweedie CC: Andrew Morton CC: Ext4 Developers List --- fs/ext4/fsync.c | 8 +-- fs/ext4/ialloc.c | 17 +++--- fs/ext4/inode.c | 79 +++++++++---------------------- fs/ext4/mballoc.c | 71 +++++++++------------------- fs/ext4/mballoc.h | 2 fs/ext4/super.c | 6 +- include/trace/ext4.h | 129 +++++++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 194 insertions(+), 118 deletions(-) Index: linux-2.6-lttng/fs/ext4/fsync.c =================================================================== --- linux-2.6-lttng.orig/fs/ext4/fsync.c 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/fsync.c 2009-03-05 15:49:28.000000000 -0500 @@ -28,10 +28,12 @@ #include #include #include -#include +#include #include "ext4.h" #include "ext4_jbd2.h" +DEFINE_TRACE(ext4_sync_file); + /* * akpm: A new design for ext4_sync_file(). * @@ -52,9 +54,7 @@ int ext4_sync_file(struct file *file, st J_ASSERT(ext4_journal_current_handle() == NULL); - trace_mark(ext4_sync_file, "dev %s datasync %d ino %ld parent %ld", - inode->i_sb->s_id, datasync, inode->i_ino, - dentry->d_parent->d_inode->i_ino); + trace_ext4_sync_file(file, dentry, datasync); /* * data=writeback: Index: linux-2.6-lttng/fs/ext4/ialloc.c =================================================================== --- linux-2.6-lttng.orig/fs/ext4/ialloc.c 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/ialloc.c 2009-03-05 15:49:28.000000000 -0500 @@ -22,6 +22,7 @@ #include #include #include +#include #include #include "ext4.h" #include "ext4_jbd2.h" @@ -29,6 +30,10 @@ #include "acl.h" #include "group.h" +DEFINE_TRACE(ext4_free_inode); +DEFINE_TRACE(ext4_request_inode); +DEFINE_TRACE(ext4_allocate_inode); + /* * ialloc.c contains the inodes allocation and deallocation routines */ @@ -210,11 +215,7 @@ void ext4_free_inode(handle_t *handle, s ino = inode->i_ino; ext4_debug("freeing inode %lu\n", ino); - trace_mark(ext4_free_inode, - "dev %s ino %lu mode %d uid %lu gid %lu bocks %llu", - sb->s_id, inode->i_ino, inode->i_mode, - (unsigned long) inode->i_uid, (unsigned long) inode->i_gid, - (unsigned long long) inode->i_blocks); + trace_ext4_free_inode(inode); /* * Note: we must free any quota before locking the superblock, @@ -703,8 +704,7 @@ struct inode *ext4_new_inode(handle_t *h return ERR_PTR(-EPERM); sb = dir->i_sb; - trace_mark(ext4_request_inode, "dev %s dir %lu mode %d", sb->s_id, - dir->i_ino, mode); + trace_ext4_request_inode(dir, mode); inode = new_inode(sb); if (!inode) return ERR_PTR(-ENOMEM); @@ -939,8 +939,7 @@ got: } ext4_debug("allocating inode %lu\n", inode->i_ino); - trace_mark(ext4_allocate_inode, "dev %s ino %lu dir %lu mode %d", - sb->s_id, inode->i_ino, dir->i_ino, mode); + trace_ext4_allocate_inode(inode, dir, mode); goto really_out; fail: ext4_std_error(sb, err); Index: linux-2.6-lttng/fs/ext4/inode.c =================================================================== --- linux-2.6-lttng.orig/fs/ext4/inode.c 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/inode.c 2009-03-05 15:49:28.000000000 -0500 @@ -37,11 +37,24 @@ #include #include #include +#include #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" #include "ext4_extents.h" +DEFINE_TRACE(ext4_write_begin); +DEFINE_TRACE(ext4_ordered_write_end); +DEFINE_TRACE(ext4_writeback_write_end); +DEFINE_TRACE(ext4_journalled_write_end); +DEFINE_TRACE(ext4_da_writepage); +DEFINE_TRACE(ext4_da_writepages); +DEFINE_TRACE(ext4_da_writepages_result); +DEFINE_TRACE(ext4_da_write_begin); +DEFINE_TRACE(ext4_da_write_end); +DEFINE_TRACE(ext4_normal_writepage); +DEFINE_TRACE(ext4_journalled_writepage); + #define MPAGE_DA_EXTENT_TAIL 0x01 static inline int ext4_begin_ordered_truncate(struct inode *inode, @@ -1353,10 +1366,7 @@ static int ext4_write_begin(struct file pgoff_t index; unsigned from, to; - trace_mark(ext4_write_begin, - "dev %s ino %lu pos %llu len %u flags %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, flags); + trace_ext4_write_begin(inode, pos, len, flags); index = pos >> PAGE_CACHE_SHIFT; from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; @@ -1432,10 +1442,7 @@ static int ext4_ordered_write_end(struct struct inode *inode = mapping->host; int ret = 0, ret2; - trace_mark(ext4_ordered_write_end, - "dev %s ino %lu pos %llu len %u copied %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, copied); + trace_ext4_ordered_write_end(inode, pos, len, copied); ret = ext4_jbd2_file_inode(handle, inode); if (ret == 0) { @@ -1474,10 +1481,7 @@ static int ext4_writeback_write_end(stru int ret = 0, ret2; loff_t new_i_size; - trace_mark(ext4_writeback_write_end, - "dev %s ino %lu pos %llu len %u copied %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, copied); + trace_ext4_writeback_write_end(inode, pos, len, copied); new_i_size = pos + copied; if (new_i_size > EXT4_I(inode)->i_disksize) { ext4_update_i_disksize(inode, new_i_size); @@ -1513,10 +1517,7 @@ static int ext4_journalled_write_end(str unsigned from, to; loff_t new_i_size; - trace_mark(ext4_journalled_write_end, - "dev %s ino %lu pos %llu len %u copied %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, copied); + trace_ext4_journalled_write_end(inode, pos, len, copied); from = pos & (PAGE_CACHE_SIZE - 1); to = from + len; @@ -2333,9 +2334,7 @@ static int ext4_da_writepage(struct page struct buffer_head *page_bufs; struct inode *inode = page->mapping->host; - trace_mark(ext4_da_writepage, - "dev %s ino %lu page_index %lu", - inode->i_sb->s_id, inode->i_ino, page->index); + trace_ext4_da_writepage(inode, page); size = i_size_read(inode); if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; @@ -2447,19 +2446,7 @@ static int ext4_da_writepages(struct add int needed_blocks, ret = 0, nr_to_writebump = 0; struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); - trace_mark(ext4_da_writepages, - "dev %s ino %lu nr_t_write %ld " - "pages_skipped %ld range_start %llu " - "range_end %llu nonblocking %d " - "for_kupdate %d for_reclaim %d " - "for_writepages %d range_cyclic %d", - inode->i_sb->s_id, inode->i_ino, - wbc->nr_to_write, wbc->pages_skipped, - (unsigned long long) wbc->range_start, - (unsigned long long) wbc->range_end, - wbc->nonblocking, wbc->for_kupdate, - wbc->for_reclaim, wbc->for_writepages, - wbc->range_cyclic); + trace_ext4_da_writepages(inode, wbc); /* * No pages to write? This is mainly a kludge to avoid starting @@ -2595,14 +2582,7 @@ out_writepages: if (!no_nrwrite_index_update) wbc->no_nrwrite_index_update = 0; wbc->nr_to_write -= nr_to_writebump; - trace_mark(ext4_da_writepage_result, - "dev %s ino %lu ret %d pages_written %d " - "pages_skipped %ld congestion %d " - "more_io %d no_nrwrite_index_update %d", - inode->i_sb->s_id, inode->i_ino, ret, - pages_written, wbc->pages_skipped, - wbc->encountered_congestion, wbc->more_io, - wbc->no_nrwrite_index_update); + trace_ext4_da_writepages_result(inode, wbc, ret, pages_written); return ret; } @@ -2654,11 +2634,7 @@ static int ext4_da_write_begin(struct fi len, flags, pagep, fsdata); } *fsdata = (void *)0; - - trace_mark(ext4_da_write_begin, - "dev %s ino %lu pos %llu len %u flags %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, flags); + trace_ext4_da_write_begin(inode, pos, len, flags); retry: /* * With delayed allocation, we don't log the i_disksize update @@ -2751,10 +2727,7 @@ static int ext4_da_write_end(struct file } } - trace_mark(ext4_da_write_end, - "dev %s ino %lu pos %llu len %u copied %u", - inode->i_sb->s_id, inode->i_ino, - (unsigned long long) pos, len, copied); + trace_ext4_da_write_end(inode, pos, len, copied); start = pos & (PAGE_CACHE_SIZE - 1); end = start + copied - 1; @@ -2965,9 +2938,7 @@ static int ext4_normal_writepage(struct loff_t size = i_size_read(inode); loff_t len; - trace_mark(ext4_normal_writepage, - "dev %s ino %lu page_index %lu", - inode->i_sb->s_id, inode->i_ino, page->index); + trace_ext4_normal_writepage(inode, page); J_ASSERT(PageLocked(page)); if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; @@ -3053,9 +3024,7 @@ static int ext4_journalled_writepage(str loff_t size = i_size_read(inode); loff_t len; - trace_mark(ext4_journalled_writepage, - "dev %s ino %lu page_index %lu", - inode->i_sb->s_id, inode->i_ino, page->index); + trace_ext4_journalled_writepage(inode, page); J_ASSERT(PageLocked(page)); if (page->index == size >> PAGE_CACHE_SHIFT) len = size & ~PAGE_CACHE_MASK; Index: linux-2.6-lttng/fs/ext4/mballoc.c =================================================================== --- linux-2.6-lttng.orig/fs/ext4/mballoc.c 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/mballoc.c 2009-03-05 15:49:28.000000000 -0500 @@ -343,6 +343,17 @@ static void release_blocks_on_commit(jou +DEFINE_TRACE(ext4_discard_blocks); +DEFINE_TRACE(ext4_mb_new_inode_pa); +DEFINE_TRACE(ext4_mb_new_group_pa); +DEFINE_TRACE(ext4_mb_release_inode_pa); +DEFINE_TRACE(ext4_mb_release_group_pa); +DEFINE_TRACE(ext4_discard_preallocations); +DEFINE_TRACE(ext4_mb_discard_preallocations); +DEFINE_TRACE(ext4_request_blocks); +DEFINE_TRACE(ext4_allocate_blocks); +DEFINE_TRACE(ext4_free_blocks); + static inline void *mb_correct_addr_and_bit(int *bit, void *addr) { #if BITS_PER_LONG == 64 @@ -2878,9 +2889,8 @@ static void release_blocks_on_commit(jou discard_block = (ext4_fsblk_t) entry->group * EXT4_BLOCKS_PER_GROUP(sb) + entry->start_blk + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); - trace_mark(ext4_discard_blocks, "dev %s blk %llu count %u", - sb->s_id, (unsigned long long) discard_block, - entry->count); + trace_ext4_discard_blocks(sb, (unsigned long long)discard_block, + entry); sb_issue_discard(sb, discard_block, entry->count); kmem_cache_free(ext4_free_ext_cachep, entry); @@ -3700,10 +3710,7 @@ ext4_mb_new_inode_pa(struct ext4_allocat mb_debug("new inode pa %p: %llu/%u for %u\n", pa, pa->pa_pstart, pa->pa_len, pa->pa_lstart); - trace_mark(ext4_mb_new_inode_pa, - "dev %s ino %lu pstart %llu len %u lstart %u", - sb->s_id, ac->ac_inode->i_ino, - pa->pa_pstart, pa->pa_len, pa->pa_lstart); + trace_ext4_mb_new_inode_pa(ac, pa); ext4_mb_use_inode_pa(ac, pa); atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); @@ -3762,9 +3769,8 @@ ext4_mb_new_group_pa(struct ext4_allocat pa->pa_linear = 1; mb_debug("new group pa %p: %llu/%u for %u\n", pa, - pa->pa_pstart, pa->pa_len, pa->pa_lstart); - trace_mark(ext4_mb_new_group_pa, "dev %s pstart %llu len %u lstart %u", - sb->s_id, pa->pa_pstart, pa->pa_len, pa->pa_lstart); + pa->pa_pstart, pa->pa_len, pa->pa_lstart); + trace_ext4_mb_new_group_pa(ac, pa); ext4_mb_use_group_pa(ac, pa); atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); @@ -3854,10 +3860,8 @@ ext4_mb_release_inode_pa(struct ext4_bud ext4_mb_store_history(ac); } - trace_mark(ext4_mb_release_inode_pa, - "dev %s ino %lu block %llu count %u", - sb->s_id, pa->pa_inode->i_ino, grp_blk_start + bit, - next - bit); + trace_ext4_mb_release_inode_pa(ac, pa, grp_blk_start + bit, + next - bit); mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); bit = next + 1; } @@ -3891,8 +3895,7 @@ ext4_mb_release_group_pa(struct ext4_bud if (ac) ac->ac_op = EXT4_MB_HISTORY_DISCARD; - trace_mark(ext4_mb_release_group_pa, "dev %s pstart %llu len %d", - sb->s_id, pa->pa_pstart, pa->pa_len); + trace_ext4_mb_release_group_pa(ac, pa); BUG_ON(pa->pa_deleted == 0); ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); BUG_ON(group != e4b->bd_group && pa->pa_len != 0); @@ -4058,8 +4061,7 @@ void ext4_discard_preallocations(struct } mb_debug("discard preallocation for inode %lu\n", inode->i_ino); - trace_mark(ext4_discard_preallocations, "dev %s ino %lu", sb->s_id, - inode->i_ino); + trace_ext4_discard_preallocations(inode); INIT_LIST_HEAD(&list); @@ -4515,8 +4517,7 @@ static int ext4_mb_discard_preallocation int ret; int freed = 0; - trace_mark(ext4_mb_discard_preallocations, "dev %s needed %d", - sb->s_id, needed); + trace_ext4_mb_discard_preallocations(sb, needed); for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) { ret = ext4_mb_discard_group_preallocations(sb, i, needed); freed += ret; @@ -4545,17 +4546,7 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t sb = ar->inode->i_sb; sbi = EXT4_SB(sb); - trace_mark(ext4_request_blocks, "dev %s flags %u len %u ino %lu " - "lblk %llu goal %llu lleft %llu lright %llu " - "pleft %llu pright %llu ", - sb->s_id, ar->flags, ar->len, - ar->inode ? ar->inode->i_ino : 0, - (unsigned long long) ar->logical, - (unsigned long long) ar->goal, - (unsigned long long) ar->lleft, - (unsigned long long) ar->lright, - (unsigned long long) ar->pleft, - (unsigned long long) ar->pright); + trace_ext4_request_blocks(ar); if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) { /* @@ -4659,18 +4650,7 @@ out3: reserv_blks); } - trace_mark(ext4_allocate_blocks, - "dev %s block %llu flags %u len %u ino %lu " - "logical %llu goal %llu lleft %llu lright %llu " - "pleft %llu pright %llu ", - sb->s_id, (unsigned long long) block, - ar->flags, ar->len, ar->inode ? ar->inode->i_ino : 0, - (unsigned long long) ar->logical, - (unsigned long long) ar->goal, - (unsigned long long) ar->lleft, - (unsigned long long) ar->lright, - (unsigned long long) ar->pleft, - (unsigned long long) ar->pright); + trace_ext4_allocate_blocks(ar, (unsigned long long)block); return block; } @@ -4805,10 +4785,7 @@ void ext4_mb_free_blocks(handle_t *handl } ext4_debug("freeing block %lu\n", block); - trace_mark(ext4_free_blocks, - "dev %s block %llu count %lu metadata %d ino %lu", - sb->s_id, (unsigned long long) block, count, metadata, - inode ? inode->i_ino : 0); + trace_ext4_free_blocks(inode, block, count, metadata); ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); if (ac) { Index: linux-2.6-lttng/fs/ext4/mballoc.h =================================================================== --- linux-2.6-lttng.orig/fs/ext4/mballoc.h 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/mballoc.h 2009-03-05 15:49:28.000000000 -0500 @@ -19,8 +19,8 @@ #include #include #include -#include #include +#include #include "ext4_jbd2.h" #include "ext4.h" #include "group.h" Index: linux-2.6-lttng/fs/ext4/super.c =================================================================== --- linux-2.6-lttng.orig/fs/ext4/super.c 2009-03-05 15:21:54.000000000 -0500 +++ linux-2.6-lttng/fs/ext4/super.c 2009-03-05 15:49:28.000000000 -0500 @@ -35,9 +35,9 @@ #include #include #include -#include #include #include +#include #include #include "ext4.h" @@ -47,6 +47,8 @@ #include "namei.h" #include "group.h" +DEFINE_TRACE(ext4_sync_fs); + struct proc_dir_entry *ext4_proc_root; static int ext4_load_journal(struct super_block *, struct ext4_super_block *, @@ -3048,7 +3050,7 @@ static int ext4_sync_fs(struct super_blo int ret = 0; tid_t target; - trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait); + trace_ext4_sync_fs(sb, wait); sb->s_dirt = 0; if (EXT4_SB(sb)->s_journal) { if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, Index: linux-2.6-lttng/include/trace/ext4.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6-lttng/include/trace/ext4.h 2009-03-05 15:49:28.000000000 -0500 @@ -0,0 +1,129 @@ +#ifndef _TRACE_EXT4_H +#define _TRACE_EXT4_H + +#include + +struct ext4_free_data; +struct ext4_prealloc_space; +struct ext4_allocation_context; +struct ext4_allocation_request; + +DECLARE_TRACE(ext4_free_inode, + TPPROTO(struct inode *inode), + TPARGS(inode)); + +DECLARE_TRACE(ext4_request_inode, + TPPROTO(struct inode *dir, int mode), + TPARGS(dir, mode)); + +DECLARE_TRACE(ext4_allocate_inode, + TPPROTO(struct inode *inode, struct inode *dir, int mode), + TPARGS(inode, dir, mode)); + +DECLARE_TRACE(ext4_write_begin, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int flags), + TPARGS(inode, pos, len, flags)); + +DECLARE_TRACE(ext4_ordered_write_end, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int copied), + TPARGS(inode, pos, len, copied)); + +DECLARE_TRACE(ext4_writeback_write_end, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int copied), + TPARGS(inode, pos, len, copied)); + +DECLARE_TRACE(ext4_journalled_write_end, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int copied), + TPARGS(inode, pos, len, copied)); + +DECLARE_TRACE(ext4_da_writepage, + TPPROTO(struct inode *inode, struct page *page), + TPARGS(inode, page)); + +DECLARE_TRACE(ext4_da_writepages, + TPPROTO(struct inode *inode, struct writeback_control *wbc), + TPARGS(inode, wbc)); + +DECLARE_TRACE(ext4_da_writepages_result, + TPPROTO(struct inode *inode, struct writeback_control *wbc, + int ret, int pages_written), + TPARGS(inode, wbc, ret, pages_written)); + +DECLARE_TRACE(ext4_da_write_begin, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int flags), + TPARGS(inode, pos, len, flags)); + +DECLARE_TRACE(ext4_da_write_end, + TPPROTO(struct inode *inode, loff_t pos, unsigned int len, + unsigned int copied), + TPARGS(inode, pos, len, copied)); + +DECLARE_TRACE(ext4_normal_writepage, + TPPROTO(struct inode *inode, struct page *page), + TPARGS(inode, page)); + +DECLARE_TRACE(ext4_journalled_writepage, + TPPROTO(struct inode *inode, struct page *page), + TPARGS(inode, page)); + +DECLARE_TRACE(ext4_discard_blocks, + TPPROTO(struct super_block *sb, unsigned long long blk, + struct ext4_free_data *entry), + TPARGS(sb, blk, entry)); + +DECLARE_TRACE(ext4_mb_new_inode_pa, + TPPROTO(struct ext4_allocation_context *ac, + struct ext4_prealloc_space *pa), + TPARGS(ac, pa)); + +DECLARE_TRACE(ext4_mb_new_group_pa, + TPPROTO(struct ext4_allocation_context *ac, + struct ext4_prealloc_space *pa), + TPARGS(ac, pa)); + +DECLARE_TRACE(ext4_mb_release_inode_pa, + TPPROTO(struct ext4_allocation_context *ac, + struct ext4_prealloc_space *pa, + unsigned long long block, unsigned int count), + TPARGS(ac, pa, block, count)); + +DECLARE_TRACE(ext4_mb_release_group_pa, + TPPROTO(struct ext4_allocation_context *ac, + struct ext4_prealloc_space *pa), + TPARGS(ac, pa)); + +DECLARE_TRACE(ext4_discard_preallocations, + TPPROTO(struct inode *inode), + TPARGS(inode)); + +DECLARE_TRACE(ext4_mb_discard_preallocations, + TPPROTO(struct super_block *sb, int needed), + TPARGS(sb, needed)); + +DECLARE_TRACE(ext4_request_blocks, + TPPROTO(struct ext4_allocation_request *ar), + TPARGS(ar)); + +DECLARE_TRACE(ext4_allocate_blocks, + TPPROTO(struct ext4_allocation_request *ar, unsigned long long block), + TPARGS(ar, block)); + +DECLARE_TRACE(ext4_free_blocks, + TPPROTO(struct inode *inode, unsigned long block, unsigned long count, + int metadata), + TPARGS(inode, block, count, metadata)); + +DECLARE_TRACE(ext4_sync_file, + TPPROTO(struct file *file, struct dentry *dentry, int datasync), + TPARGS(file, dentry, datasync)); + +DECLARE_TRACE(ext4_sync_fs, + TPPROTO(struct super_block *sb, int wait), + TPARGS(sb, wait)); + +#endif -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/