From: neha agarwal <neha.agbk@gmail.com>
To: "Kirill A. Shutemov" <kirill@shutemov.name>
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: Fri, 27 May 2016 12:28:01 -0400 [thread overview]
Message-ID: <CADf8yxLK5KE1JBC9m0P+-DgXqt6GPQwRjsTeGkff01-FWQS6MQ@mail.gmail.com> (raw)
In-Reply-To: <20160525212129.GB15857@node.shutemov.name>
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On Wed, May 25, 2016 at 5:21 PM, Kirill A. Shutemov <kirill@shutemov.name>
wrote:
> 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.
>
With default khugepaged options also, the performance difference between
the two implementation remains as before.
> 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.
>
Since the performance difference is still there with default khugepaged
settings, probably khugepaged is not the culprit here.
>
> 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
>
--
Thanks and Regards,
Neha
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next prev parent reply other threads:[~2016-05-27 16:28 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
2016-05-27 16:28 ` neha agarwal [this message]
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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