Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx> writes: > Replace CR_FAST with ext4_mb_cr_expensive() inline function for better > readability. This function returns true if the criteria is one of the > expensive/slower ones where lots of disk IO/prefetching is acceptable. > > No functional changes are intended in this patch. > > Signed-off-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx> > Reviewed-by: Jan Kara <jack@xxxxxxx> > --- > > Changes since v1 [1] > > * reworded an if condition in ext_mb_good_group_nolock > and added a comment to better describe the intent of the > condition > * Picked up RVB from Jan. > > [1] > https://lore.kernel.org/linux-ext4/ZJ2YIr5EVbz4ezIc@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/#ma9428de15c4084937274f4d66dcd4d53f505d32a > > fs/ext4/ext4.h | 7 ++++--- > fs/ext4/mballoc.c | 13 +++++++++---- > 2 files changed, 13 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 45a531446ea2..e404169a2858 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -176,9 +176,6 @@ enum criteria { > EXT4_MB_NUM_CRS > }; > > -/* criteria below which we use fast block scanning and avoid unnecessary IO */ > -#define CR_FAST CR_GOAL_LEN_SLOW > - > /* > * Flags used in mballoc's allocation_context flags field. > * > @@ -2924,6 +2921,10 @@ extern int ext4_trim_fs(struct super_block *, struct fstrim_range *); > extern void ext4_process_freed_data(struct super_block *sb, tid_t commit_tid); > extern void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, > int len, int state); > +static inline bool ext4_mb_cr_expensive(enum criteria cr) > +{ > + return cr >= CR_GOAL_LEN_SLOW; > +} > > /* inode.c */ > void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw, > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index a2475b8c9fb5..542577f621c6 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -2446,7 +2446,7 @@ void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, > break; > } > > - if (ac->ac_criteria < CR_FAST) { > + if (!ext4_mb_cr_expensive(ac->ac_criteria)) { > /* > * In CR_GOAL_LEN_FAST and CR_BEST_AVAIL_LEN, we are > * sure that this group will have a large enough > @@ -2630,7 +2630,12 @@ static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, > free = grp->bb_free; > if (free == 0) > goto out; > - if (cr <= CR_FAST && free < ac->ac_g_ex.fe_len) > + /* > + * In all criterias except CR_ANY_FREE we try to avoid groups that > + * can't possibly satisfy the full goal request due to insufficient > + * free blocks. > + */ > + if (cr < CR_ANY_FREE && free < ac->ac_g_ex.fe_len) > goto out; cr CR_BEST_AVAIL_LEN, is the one where we can allocate something smaller than the original goal length. But in that we alter the goal length itself while selecting the criteria. So checking free < ac->ac_g_ex.fe_len should work here. Looks good to me. Feel free to add - Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx> > if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(grp))) > goto out; > @@ -2654,7 +2659,7 @@ static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, > * sure we locate metadata blocks in the first block group in > * the flex_bg if possible. > */ > - if (cr < CR_FAST && > + if (!ext4_mb_cr_expensive(cr) && > (!sbi->s_log_groups_per_flex || > ((group & ((1 << sbi->s_log_groups_per_flex) - 1)) != 0)) && > !(ext4_has_group_desc_csum(sb) && > @@ -2848,7 +2853,7 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) > * spend a lot of time loading imperfect groups > */ > if ((prefetch_grp == group) && > - (cr >= CR_FAST || > + (ext4_mb_cr_expensive(cr) || > prefetch_ios < sbi->s_mb_prefetch_limit)) { > nr = sbi->s_mb_prefetch; > if (ext4_has_feature_flex_bg(sb)) { > -- > 2.31.1 -ritesh
