From mboxrd@z Thu Jan  1 00:00:00 1970
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: Dirty/Access bits vs. page content
Date: Fri, 25 Apr 2014 12:41:40 +1000
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On Fri, 2014-04-25 at 11:37 +1000, Benjamin Herrenschmidt wrote:
> On Thu, 2014-04-24 at 16:46 -0700, Linus Torvalds wrote:
> > - we do the TLB shootdown holding the page table lock (but that's not
> > new - ptep_get_and_flush does the same
> > 
> 
> The flip side is that we do a lot more IPIs for large invalidates,
> since we drop the PTL on every page table page.

Oh I missed that your patch was smart enough to only do that in the
presence of non-anonymous dirty pages. That should take care of the
common case of short lived programs, those should still fit in a
single big batch.

Cheers,
Ben.