Re: [PATCH 1/2] x86: mmu.h: move mm_context_t::lock member inside CONFIG_MODIFY_LDT_SYSCALL

From: Rasmus Villemoes
Date: Mon Oct 07 2019 - 04:56:15 EST


On 28/08/2019 21.38, Rasmus Villemoes wrote:
> The placement of the lock member in mm_context_t suggests that it is
> used to protect the vdso* members, but AFAICT, it is only ever used
> under #ifdef CONFIG_MODIFY_LDT_SYSCALL. So guarding the member by the
> same config option is a cheap way to reduce sizeof(mm_struct) by 32
> bytes (only for !CONFIG_MODIFY_LDT_SYSCALL kernels, of course).

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