Re: [RFC PATCH] fs: introduce ST_HUGE flag and set it to tmpfs and hugetlbfs

[Kirill A. Shutemov]

On Thu, Apr 19, 2018 at 01:28:10AM -0700, Christoph Hellwig wrote:
> On Wed, Apr 18, 2018 at 11:18:25AM -0700, Yang Shi wrote:
> > Yes, thanks for the suggestion. I did think about it before I went with the
> > new flag. Not like hugetlb, THP will *not* guarantee huge page is used all
> > the time, it may fallback to regular 4K page or may get split. I'm not sure
> > how the applications use f_bsize field, it might break existing applications
> > and the value might be abused by applications to have counter optimization.
> > So, IMHO, a new flag may sound safer.
> 
> But st_blksize isn't the block size, that is why I suggested it.  It is
> the preferred I/O size, and various file systems can report way
> larger values than the block size already.

I agree. This looks like a better fit.

-- 
 Kirill A. Shutemov