Re: [RFC, patch] i386: vgetcpu(), take 2

[Andi Kleen]

> Can we use similar  mechanism to access pda in vsyscall in x86_64 (by
> storing the address of pda there).  


You mean in the kernel? %gs prefix is a lot faster than this.

Also the limit is only 20bit, not enough for a full address.

For user space it's useful though, but I don't see any immediate uses
other than cpu number and node number. For most purposes glibc TLS
(which uses %fs) is probably sufficient.

-Andi
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