> -----Original Message----- > From: Peter Zijlstra [mailto:a.p.zijlstra@xxxxxxxxx] > Sent: Friday, March 04, 2011 8:17 PM > To: Guan Xuetao > Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-arch@xxxxxxxxxxxxxxx; linux-mm@xxxxxxxxx; 'Benjamin Herrenschmidt'; 'David Miller'; 'Hugh > Dickins'; 'Mel Gorman'; 'Nick Piggin'; 'Paul McKenney'; 'Yanmin Zhang'; 'Andrea Arcangeli'; 'Avi Kivity'; 'Thomas Gleixner'; 'Rik van Riel'; > 'Ingo Molnar'; akpm@xxxxxxxxxxxxxxxxxxxx; 'Linus Torvalds'; Arnd Bergmann > Subject: RE: [PATCH 09/13] unicore: mmu_gather rework > > On Fri, 2011-03-04 at 19:56 +0800, Guan Xuetao wrote: > > > Thanks Peter. > > It looks good to me, though it is dependent on your patch set "mm: Preemptible mmu_gather" > > It is indeed, the split-out per arch is purely to ease review. The final > commit should be a merge of the first 10 patches so as not to break > bisection. > > > While I have another look to include/asm-generic/tlb.h, I found it is also suitable for unicore32. > > And so, I rewrite the tlb.h to use asm-generic version, and then your patch set will also work for me. > > Awesome, I notice you're loosing flush_tlb_range() support for this, if > you're fine with that I'm obviously not going to argue, but if its > better for your platform to keep doing this we can work on that as well > as I'm trying to add generic support for range tracking into the generic > tlb code. Yes, I think flush_tlb_range() have no effect in unicore32 architecture. Or perhaps, it is because no optimization, just as you point it below. > > More importantly, you seem to loose your call to flush_cache_range() > which isn't a NOP on your platform. IMO, flush_cache_range() is only used in self-modified codes when cachetype is vipt. So, it could be neglected here. Perhaps it's wrong. > > Furthermore, while arch/unicore32/mm/tlb-ucv2.S is mostly magic to me, I > see unicore32 is one of the few architectures that actually uses > vm_flags in flush_tlb_range(). Do you have independent I/D-TLB flushes > or are you flushing I-cache on VM_EXEC? We have both independent and global I/D TLB flushes. And flushing I-cache on VM_EXEC is also needed in self-modified codes, IMO. > > Also, I notice your flush_tlb_range() implementation looks to be a loop > invalidating individual pages, which I can imagine is cheaper for small > ranges but large ranges might be better of with a full invalidate. Did > you think about this? > Yes, it should be optimized. However, I doubt its effect in unicore32 which has no asid support. Thanks & Regards. Guan Xuetao -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href