>>> I guess you're doing buffered IO, have you try to use direct IO? >>> >> Direct I/O is another case, it is true that will bypass readahead. >> But I want to disable readahead with page cache. > >don't get me wrong but when you state "I am newbie on ext4" this all sounds >like "having solution, seeking for problem" No solution, I only want to disable ext4 readahead with keeping page cache. I am curious about that flash based SDD/UFS/eMMC already has readahead in the FW, what is benefit of readahead in the FS under this condition?
