Re: [PATCHv4 33/39] thp, mm: implement do_huge_linear_fault()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hillf Danton wrote:
> On Sun, May 12, 2013 at 9:23 AM, Kirill A. Shutemov
> <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
> >         page = vmf.page;
> > +
> > +       /*
> > +        * If we asked for huge page we expect to get it or VM_FAULT_FALLBACK.
> > +        * If we don't ask for huge page it must be splitted in ->fault().
> > +        */
> > +       BUG_ON(PageTransHuge(page) != thp);
> > +
> Based on the log message in 34/39(
> If the area of page cache required to create huge is empty, we create a
> new huge page and return it.), the above trap looks bogus.

The statement in 34/39 is true for (flags & FAULT_FLAG_TRANSHUGE).
For !(flags & FAULT_FLAG_TRANSHUGE) huge page must be split in ->fault.

The BUG_ON() above is shortcut for two checks:

if (thp)
	BUG_ON(!PageTransHuge(page));
if (!thp)
	BUG_ON(PageTransHuge(page));

-- 
 Kirill A. Shutemov
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux