Re: [RFC][PATCH 0/2] fun with tlb flushing on s390
From: Peter Zijlstra <peterz@infradead.org>
Date: 2012-07-26 19:42:57
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linux-arch
On Thu, 2012-07-26 at 17:47 +0200, Martin Schwidefsky wrote:
A code review revealed another potential race in regard to TLB flushing on s390. See patch #2 for the ugly details. To fix this I would like to use the arch_enter_lazy_mmu_mode/arch_leave_lazy_mmu_mode but to do that the pointer to the mm in question needs to be added to the functions. To keep things symmetrical arch_flush_lazy_mmu_mode should grow an mm argument as well. powerpc
I have a patch that makes sparc64 do the same thing.
and x86 have a non-empty implementation for the lazy mmu flush primitives and tile calls the generic definition in the architecture files (which is a bit strange because the generic definition is empty). Comments?
argh.. you're making my head hurt. I guess my first question is where is lazy_mmu_mode active crossing an mm? I thought it was only ever held across operations on a single mm. The second question would be if you could use that detach_mm thing I proposed a while back ( http://marc.info/?l=linux-mm&m=134090072917840 ) or can we rework the active_mm magic in general to make all this easier? Your 2/2 patch makes me shiver.. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>