Re: [PATCH RFC v3 1/2] mm: Add personality flag to limit address to 47 bits
Charlie Jenkins <[email protected]>
| Newsgroups | gmane.linux.kernel.cross-arch,gmane.linux.kernel,gmane.linux.ports.alpha,gmane.linux.kernel.arc,gmane.linux.ports.arm.kernel,gmane.linux.ports.mips,gmane.linux.ports.parisc,gmane.linux.ports.ppc64.devel,gmane.linux.ports.sh.devel,gmane.linux.ports.sparc,gmane.linux.kernel.mm |
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| Message-ID | <Zt9HboH/PmPlRPmH@ghost> |
On Fri, Sep 06, 2024 at 04:59:40PM +1000, Michael Ellerman wrote: > Charlie Jenkins <[email protected]> writes: > > Create a personality flag ADDR_LIMIT_47BIT to support applications > > that wish to transition from running in environments that support at > > most 47-bit VAs to environments that support larger VAs. This > > personality can be set to cause all allocations to be below the 47-bit > > boundary. Using MAP_FIXED with mmap() will bypass this restriction. > > > > Signed-off-by: Charlie Jenkins <[email protected]> > > --- > > include/uapi/linux/personality.h | 1 + > > mm/mmap.c | 3 +++ > > 2 files changed, 4 insertions(+) > > > > diff --git a/include/uapi/linux/personality.h b/include/uapi/linux/personality.h > > index 49796b7756af..cd3b8c154d9b 100644 > > --- a/include/uapi/linux/personality.h > > +++ b/include/uapi/linux/personality.h > > @@ -22,6 +22,7 @@ enum { > > WHOLE_SECONDS = 0x2000000, > > STICKY_TIMEOUTS = 0x4000000, > > ADDR_LIMIT_3GB = 0x8000000, > > + ADDR_LIMIT_47BIT = 0x10000000, > > }; > > I wonder if ADDR_LIMIT_128T would be clearer? > I don't follow, what does 128T represent? > Have you looked at writing an update for the personality(2) man page? :) I will write an update to the man page if this patch is approved! > > cheers - Charlie