On Tue, Jul 14, 2020 at 11:32:52AM +0800, Hillf Danton wrote: > > Add FALLOC_FL_NOBLOCK and on the shmem side try to lock inode upon the > new flag. And the overall upside is to keep the current gfp either in > the khugepaged context or not. > > --- a/include/uapi/linux/falloc.h > +++ b/include/uapi/linux/falloc.h > @@ -77,4 +77,6 @@ > */ > #define FALLOC_FL_UNSHARE_RANGE 0x40 > > +#define FALLOC_FL_NOBLOCK 0x80 > + You can't add a new UAPI flag to fix a kernel-internal problem like this. - Eric
