On 06/28/2012 02:33 AM, Seth Jennings wrote: > On 06/27/2012 10:12 AM, Dan Magenheimer wrote: >>> From: Minchan Kim [mailto:minchan@xxxxxxxxxx] >>> Subject: Re: [PATCH 3/3] x86: add local_tlb_flush_kernel_range() >>> >>> On 06/27/2012 03:14 PM, Alex Shi wrote: >>>> >>>> On 06/27/2012 01:53 PM, Minchan Kim wrote: >>>> Different CPU type has different balance point on the invlpg replacing >>>> flush all. and some CPU never get benefit from invlpg, So, it's better >>>> to use different value for different CPU, not a fixed >>>> INVLPG_BREAK_EVEN_PAGES. >>> >>> I think it could be another patch as further step and someone who are >>> very familiar with architecture could do better than. >>> So I hope it could be merged if it doesn't have real big problem. >>> >>> Thanks for the comment, Alex. >> >> Just my opinion, but I have to agree with Alex. Hardcoding >> behavior that is VERY processor-specific is a bad idea. TLBs should >> only be messed with when absolutely necessary, not for the >> convenience of defending an abstraction that is nice-to-have >> but, in current OS kernel code, unnecessary. > > I agree that it's not optimal. The selection based on CPUID > is part of Alex's patchset, and I'll be glad to use that > code when it gets integrated. > > But the real discussion is are we going to: > 1) wait until Alex's patches to be integrated, degrading > zsmalloc in the meantime or Peter Anvin is merging my TLB patch set into tip tree, x86/mm branch. > 2) put in some simple temporary logic that works well (not > best) for most cases -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>