On Dec 03, 2007 13:05 -0600, Jose R. Santos wrote: > @@ -600,6 +600,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct > super_block *sb, > ext4_grpblk_t group_freed; > + ext4_group_t meta_group;
Please do not call these meta_groups. This already means something very specific (i.e. desc_per_block groups) and using it for FLEX_BG is confusing. One possibly desirable relation is if the FLEX_BG count is some integer or power-of-two multiple of the metabg count. That would allow the FLEX_BG code to share the same in-memory group struct as the mballoc code and save on some memory overhead. > + meta_group = ext4_meta_group(sbi, block_group); > + > spin_lock(&sbi->s_meta_groups[meta_group].meta_group_lock); > + sbi->s_meta_groups[meta_group].free_inodes++; > + if (is_directory) > + sbi->s_meta_groups[meta_group].num_dirs--; > + > spin_unlock(&sbi->s_meta_groups[meta_group].meta_group_lock); This can be as many as hundreds or thousands of spin locks. Why not use the same hashed locking code as the group descriptors themselves? spin_lock(sb_bgl_lock(sbi, meta_group)); spin_unlock(sb_bgl_lock(sbi, meta_group)); This scales with the number of CPUs and chance of contention is very low. > +int find_group_meta(struct super_block *sb, struct inode *parent) > +{ > + ext4_group_t parent_mgroup = parent_group / sbi->s_groups_per_meta; This could use ext4_meta_group(sbi, parent_group)? > +static inline ext4_group_t ext4_meta_group(struct ext4_sb_info *sbi, > + ext4_group_t block_group) > +{ > + return block_group/sbi->s_groups_per_meta; > +} It would be preferable to limit s_groups_per_meta to be a power-of-two so that this can become a shift instead of a divide. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html