From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: neha agarwal <neha.agbk@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Hugh Dickins <hughd@google.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Vlastimil Babka <vbabka@suse.cz>,
Christoph Lameter <cl@gentwo.org>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Jerome Marchand <jmarchan@redhat.com>,
Yang Shi <yang.shi@linaro.org>,
Sasha Levin <sasha.levin@oracle.com>,
Andres Lagar-Cavilla <andreslc@google.com>,
Ning Qu <quning@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCHv8 00/32] THP-enabled tmpfs/shmem using compound pages
Date: Thu, 26 May 2016 00:21:30 +0300 [thread overview]
Message-ID: <20160525212129.GB15857@node.shutemov.name> (raw)
In-Reply-To: <CADf8yx+_EEwys7mip0HspKGMGpacws93afX1zKtHLOmF6-Lj1g@mail.gmail.com>
On Wed, May 25, 2016 at 05:11:03PM -0400, neha agarwal wrote:
> On Wed, May 25, 2016 at 4:03 PM, Kirill A. Shutemov <kirill@shutemov.name>
> wrote:
>
> > On Wed, May 25, 2016 at 03:11:55PM -0400, neha agarwal wrote:
> > > Hi All,
> > >
> > > I have been testing Hugh's and Kirill's huge tmpfs patch sets with
> > > Cassandra (NoSQL database). I am seeing significant performance gap
> > between
> > > these two implementations (~30%). Hugh's implementation performs better
> > > than Kirill's implementation. I am surprised why I am seeing this
> > > performance gap. Following is my test setup.
> >
> > Thanks for the report. I'll look into it.
> >
>
> Thanks Kirill for looking into it.
>
>
> > > Patchsets
> > > ========
> > > - For Hugh's:
> > > I checked out 4.6-rc3, applied Hugh's preliminary patches (01 to 10
> > > patches) from here: https://lkml.org/lkml/2016/4/5/792 and then applied
> > the
> > > THP patches posted on April 16 (01 to 29 patches).
> > >
> > > - For Kirill's:
> > > I am using his branch "git://
> > > git.kernel.org/pub/scm/linux/kernel/git/kas/linux.git hugetmpfs/v8",
> > which
> > > is based off of 4.6-rc3, posted on May 12.
> > >
> > >
> > > Khugepaged settings
> > > ================
> > > cd /sys/kernel/mm/transparent_hugepage
> > > echo 10 >khugepaged/alloc_sleep_millisecs
> > > echo 10 >khugepaged/scan_sleep_millisecs
> > > echo 511 >khugepaged/max_ptes_none
> >
> > Do you make this for both setup?
> >
> > It's not really nessesary for Hugh's, but it makes sense to have this
> > idenatical for testing.
> >
>
> Yeah right, Hugh's will not be impacted by these settings but for identical
> testing I did that.
Could you try to drop this changes and leave khugepaged with defaults.
One theory is that you just create additional load on the system without
any gain. As pages wasn't swapped out we have nothing to collapse back,
but scanning takes CPU time.
Hugh didn't change khugepaged, so it would not need to look into tmpfs
mapping to check if there's something to collapse...
--
Kirill A. Shutemov
next prev parent reply other threads:[~2016-05-25 21:21 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-12 15:40 [PATCHv8 00/32] THP-enabled tmpfs/shmem using compound pages Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 01/32] thp, mlock: update unevictable-lru.txt Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 02/32] mm: do not pass mm_struct into handle_mm_fault Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 03/32] mm: introduce fault_env Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 04/32] mm: postpone page table allocation until we have page to map Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 05/32] rmap: support file thp Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 06/32] mm: introduce do_set_pmd() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 07/32] thp, vmstats: add counters for huge file pages Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 08/32] thp: support file pages in zap_huge_pmd() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 09/32] thp: handle file pages in split_huge_pmd() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 10/32] thp: handle file COW faults Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 11/32] thp: skip file huge pmd on copy_huge_pmd() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 12/32] thp: prepare change_huge_pmd() for file thp Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 13/32] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 14/32] thp: file pages support for split_huge_page() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 15/32] thp, mlock: do not mlock PTE-mapped file huge pages Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 16/32] vmscan: split file huge pages before paging them out Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 17/32] page-flags: relax policy for PG_mappedtodisk and PG_reclaim Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 18/32] radix-tree: implement radix_tree_maybe_preload_order() Kirill A. Shutemov
2016-05-12 15:40 ` [PATCHv8 19/32] filemap: prepare find and delete operations for huge pages Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 20/32] truncate: handle file thp Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 21/32] mm, rmap: account shmem thp pages Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 22/32] shmem: prepare huge= mount option and sysfs knob Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 23/32] shmem: get_unmapped_area align huge page Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 24/32] shmem: add huge pages support Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 25/32] shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 26/32] thp: update Documentation/vm/transhuge.txt Kirill A. Shutemov
2016-05-19 16:20 ` Julien Grall
2016-05-20 10:33 ` Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 27/32] thp: extract khugepaged from mm/huge_memory.c Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 28/32] khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page() Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 29/32] shmem: make shmem_inode_info::lock irq-safe Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 30/32] khugepaged: add support of collapse for tmpfs/shmem pages Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 31/32] thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE Kirill A. Shutemov
2016-05-12 15:41 ` [PATCHv8 32/32] shmem: split huge pages beyond i_size under memory pressure Kirill A. Shutemov
2016-05-25 19:11 ` [PATCHv8 00/32] THP-enabled tmpfs/shmem using compound pages neha agarwal
2016-05-25 20:03 ` Kirill A. Shutemov
2016-05-25 21:11 ` neha agarwal
2016-05-25 21:21 ` Kirill A. Shutemov [this message]
2016-05-27 16:28 ` neha agarwal
2016-06-06 13:51 ` Kirill A. Shutemov
2016-06-08 18:43 ` neha agarwal
2016-06-13 9:06 ` Kirill A. Shutemov
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