On Saturday, 7 September 2013 02:10:02 UTC+8, Naoya Horiguchi wrote:
Hi Alex, On Fri, Sep 06, 2013 at 11:04:23AM -0500, Alex Thorlton wrote: > On Thu, Sep 05, 2013 at 05:27:46PM -0400, Naoya Horiguchi wrote: > > Thp related code also uses per process mm->page_table_lock now. > > So making it fine-grained can provide better performance. > > > > This patch makes thp support split page table lock by using page->ptl > > of the pages storing "pmd_trans_huge" pmds. > > > > Some functions like pmd_trans_huge_lock() and
page_check_address_pmd()
> > are expected by their caller to pass back the pointer of ptl, so this > > patch adds to those functions new arguments for that. Rather than
that,
> > this patch gives only straightforward replacement. > > > > ChangeLog v3: > > - fixed argument of huge_pmd_lockptr() in copy_huge_pmd() > > - added missing declaration of ptl in do_huge_pmd_anonymous_page() > > I've applied these and tested them using the same tests program that I > used when I was working on the same issue, and I'm running into some > bugs. Here's a stack trace: Thank you for helping testing. This bug is new to me.
With 3.11, this patch series and CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS, I consistently hit the same failure when exiting one of my stress-testers [1] when using eg 24 cores.
Doesn't happen with 8 cores, so likely needs enough virtual memory to use multiple split locks. Otherwise, this is very promising work!
[1] http://quora.org/2013/fft3d.c -- Daniel J Blueman Principal Software Engineer, Numascale -- 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>