Re: [PATCH v5 2/4] x86/ldt: Make modify_ldt synchronous

From: H. Peter Anvin
Date: Thu Aug 13 2015 - 17:07:22 EST

On 07/27/2015 10:29 PM, Andy Lutomirski wrote:
> modify_ldt has questionable locking and does not synchronize
> threads. Improve it: redesign the locking and synchronize all
> threads' LDTs using an IPI on all modifications.
> This will dramatically slow down modify_ldt in multithreaded
> programs, but there shouldn't be any multithreaded programs that
> care about modify_ldt's performance in the first place.


... except 32-bit programs compiled with one specific version of glibc.
Do we care? I don't think so.


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