On Tue 17-08-21 22:56:54, Shaoying Xu wrote: > Ext4 file system has default lazy inode table initialization setup once > it is mounted. However, it has issue on computing the next schedule time > that makes the timeout same amount in jiffies but different real time in > secs if with various HZ values. Therefore, fix by measuring the current > time in a more granular unit nanoseconds and make the next schedule time > independent of the HZ value. > > Fixes: bfff68738f1c ("ext4: add support for lazy inode table initialization") > Signed-off-by: Shaoying Xu <shaoyi@xxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx Thanks for the patch. It seems to have fallen through the cracks. It looks good just some nits: The timeout will be still dependent on the HZ value because we use jiffie-granular timer. But yes, I guess it is unnecessary to make the imprecision 10x worse when we know we are likely dealing with small numbers. > @@ -3460,14 +3460,13 @@ static int ext4_run_li_request(struct ext4_li_request *elr) > ret = 1; > > if (!ret) { Please add a comment here so that we don't forget. Like: /* Use ns-granular time as init can be really fast */ With this feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> > - timeout = jiffies; > + start_time = ktime_get_real_ns(); > ret = ext4_init_inode_table(sb, group, > elr->lr_timeout ? 0 : 1); > trace_ext4_lazy_itable_init(sb, group); > if (elr->lr_timeout == 0) { > - timeout = (jiffies - timeout) * > - EXT4_SB(elr->lr_super)->s_li_wait_mult; > - elr->lr_timeout = timeout; > + elr->lr_timeout = nsecs_to_jiffies((ktime_get_real_ns() - start_time) * > + EXT4_SB(elr->lr_super)->s_li_wait_mult); > } > elr->lr_next_sched = jiffies + elr->lr_timeout; > elr->lr_next_group = group + 1; Honza -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR