Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1480174

Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out

From Tim Chen <tim.c.chen@linux.intel.com>
Newsgroups linux.kernel
Subject Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out
Date 2016-09-09 18:00 +0200
Message-ID <sfwnD-4Sy-1@gated-at.bofh.it> (permalink)
References <seOcV-2cL-5@gated-at.bofh.it> <sfmRj-7nj-11@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw

On Fri, 2016-09-09 at 14:43 +0900, Minchan Kim wrote:
> Hi Huang,
> 
> On Wed, Sep 07, 2016 at 09:45:59AM -0700, Huang, Ying wrote:
> > 
> > From: Huang Ying <ying.huang@intel.com>
> > 
> > This patchset is to optimize the performance of Transparent Huge Page
> > (THP) swap.
> > 
> > Hi, Andrew, could you help me to check whether the overall design is
> > reasonable?
> > 
> > Hi, Hugh, Shaohua, Minchan and Rik, could you help me to review the
> > swap part of the patchset?  Especially [01/10], [04/10], [05/10],
> > [06/10], [07/10], [10/10].
> > 
> > Hi, Andrea and Kirill, could you help me to review the THP part of the
> > patchset?  Especially [02/10], [03/10], [09/10] and [10/10].
> > 
> > Hi, Johannes, Michal and Vladimir, I am not very confident about the
> > memory cgroup part, especially [02/10] and [03/10].  Could you help me
> > to review it?
> > 
> > And for all, Any comment is welcome!
> > 
> > 
> > Recently, the performance of the storage devices improved so fast that
> > we cannot saturate the disk bandwidth when do page swap out even on a
> > high-end server machine.  Because the performance of the storage
> > device improved faster than that of CPU.  And it seems that the trend
> > will not change in the near future.  On the other hand, the THP
> > becomes more and more popular because of increased memory size.  So it
> > becomes necessary to optimize THP swap performance.
> > 
> > The advantages of the THP swap support include:
> > 
> > - Batch the swap operations for the THP to reduce lock
> >   acquiring/releasing, including allocating/freeing the swap space,
> >   adding/deleting to/from the swap cache, and writing/reading the swap
> >   space, etc.  This will help improve the performance of the THP swap.
> > 
> > - The THP swap space read/write will be 2M sequential IO.  It is
> >   particularly helpful for the swap read, which usually are 4k random
> >   IO.  This will improve the performance of the THP swap too.
> > 
> > - It will help the memory fragmentation, especially when the THP is
> >   heavily used by the applications.  The 2M continuous pages will be
> >   free up after THP swapping out.
> I just read patchset right now and still doubt why the all changes
> should be coupled with THP tightly. Many parts(e.g., you introduced
> or modifying existing functions for making them THP specific) could
> just take page_list and the number of pages then would handle them
> without THP awareness.
> 
> For example, if the nr_pages is larger than SWAPFILE_CLUSTER, we
> can try to allocate new cluster. With that, we could allocate new
> clusters to meet nr_pages requested or bail out if we fail to allocate
> and fallback to 0-order page swapout. With that, swap layer could
> support multiple order-0 pages by batch.
> 
> IMO, I really want to land Tim Chen's batching swapout work first.
> With Tim Chen's work, I expect we can make better refactoring
> for batching swap before adding more confuse to the swap layer.
> (I expect it would share several pieces of code for or would be base
> for batching allocation of swapcache, swapslot)

Minchan,

Ying and I do plan to send out a new patch series on batching swapout
and swapin plus a few other optimization on the swapping of 
regular sized pages.

Hopefully we'll be able to do that soon after we fixed up a few
things and retest.

Tim

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
  [PATCH -v3 02/10] mm, memcg: Add swap_cgroup_iter iterator "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
  [PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:20 +0200
      Re: [PATCH -v3 08/10] mm, THP: Add can_split_huge_page() "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:10 +0200
  [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:30 +0200
    Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:20 +0200
      Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:10 +0200
      Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 Johannes Weiner <hannes@cmpxchg.org> - 2016-09-19 19:20 +0200
        Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 Johannes Weiner <hannes@cmpxchg.org> - 2016-09-22 21:30 +0200
    Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:10 +0200
      Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:40 +0200
    Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP  size on x86_64 "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:10 +0200
      Re: [PATCH -v3 01/10] mm, swap: Make swap cluster size same of THP size on x86_64 "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:30 +0200
  [PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Kirill A. Shutemov" <kirill@shutemov.name> - 2016-09-08 13:20 +0200
      Re: [PATCH -v3 05/10] mm, THP, swap: Add get_huge_swap_page() "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 19:30 +0200
  [PATCH -v3 09/10] mm, THP, swap: Support to split THP in swap cache "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
  [PATCH -v3 06/10] mm, THP, swap: Support to clear SWAP_HAS_CACHE for huge page "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
  [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple  swap entries Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:30 +0200
      Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple swap entries "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
    Re: [PATCH -v3 03/10] mm, memcg: Support to charge/uncharge multiple  swap entries Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:40 +0200
  [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free  functions Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 10:40 +0200
      Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free functions "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
    Re: [PATCH -v3 04/10] mm, THP, swap: Add swap cluster allocate/free  functions Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:00 +0200
  [PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from swap cache "Huang, Ying" <ying.huang@intel.com> - 2016-09-07 18:50 +0200
    Re: [PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from  swap cache Anshuman Khandual <khandual@linux.vnet.ibm.com> - 2016-09-08 11:10 +0200
      Re: [PATCH -v3 07/10] mm, THP, swap: Support to add/delete THP to/from swap cache "Huang\, Ying" <ying.huang@intel.com> - 2016-09-08 20:20 +0200
  Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-09 07:50 +0200
    Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Tim Chen <tim.c.chen@linux.intel.com> - 2016-09-09 18:00 +0200
    Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-09 22:40 +0200
      Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-13 08:20 +0200
        Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-13 08:50 +0200
          Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-13 09:10 +0200
            Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-13 11:00 +0200
              Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-13 11:20 +0200
                RE: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out "Chen, Tim C" <tim.c.chen@intel.com> - 2016-09-14 02:00 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-19 09:20 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Tim Chen <tim.c.chen@linux.intel.com> - 2016-09-19 18:00 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-18 04:00 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-19 09:10 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-20 05:00 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-20 07:30 +0200
                Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Minchan Kim <minchan@kernel.org> - 2016-09-20 07:40 +0200
              Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Andrea Arcangeli <aarcange@redhat.com> - 2016-09-13 16:40 +0200
  Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Hugh Dickins <hughd@google.com> - 2016-09-19 19:40 +0200
  Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Shaohua Li <shli@kernel.org> - 2016-09-23 01:00 +0200
    RE: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out "Chen, Tim C" <tim.c.chen@intel.com> - 2016-09-23 01:50 +0200
      Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Andi Kleen <andi@firstfloor.org> - 2016-09-23 02:00 +0200
    Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping  out Rik van Riel <riel@redhat.com> - 2016-09-23 02:40 +0200
      Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-23 04:40 +0200
    Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-23 04:20 +0200

csiph-web