Re: [PATCH 3/3] ext4: Use readahead when reading an inode from the inode table

[Eric Sandeen <sandeen@redhat.com>]

Andreas Dilger wrote:
> On Sep 24, 2008  12:53 -0400, Theodore Ts'o wrote:
>> @@ -514,8 +514,10 @@ static void ext4_put_super(struct super_block *sb)
>> +	if (sbi->s_proc) {
>> +		remove_proc_entry("inode_readahead_bits", sbi->s_proc);
>>  		remove_proc_entry(sb->s_id, ext4_proc_root);
> 
> As a general UI interface, specifying the "bits to shift the filesystem
> block number" seems like an easy-to-implement but is fairly bad from
> a usability point of view.  I'd much prefer to specify this as a
> number of kB to readahead, and it can be converted internally to the
> number of blocks to readahead.  It isn't fatal if we do a bit of rounding
> on the input value to match a full blocksize.

Or specify that it must be a power of two in some range, and reject
other values - either way.

I had the same thought about the nr of bits as a user input value...

-Eric