From: Mike Kravetz <mike.kravetz@oracle.com>
To: Michal Hocko <mhocko@kernel.org>, "Huang, Ying" <ying.huang@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Andi Kleen <andi.kleen@intel.com>, Jan Kara <jack@suse.cz>,
Andrea Arcangeli <aarcange@redhat.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Matthew Wilcox <mawilcox@microsoft.com>,
Hugh Dickins <hughd@google.com>, Minchan Kim <minchan@kernel.org>,
Shaohua Li <shli@fb.com>, Christopher Lameter <cl@linux.com>
Subject: Re: [PATCH -mm] mm, huge page: Copy to access sub-page last when copy huge page
Date: Fri, 18 May 2018 09:41:04 -0700 [thread overview]
Message-ID: <64430ed4-4019-d597-ccb3-8bf6b04ee464@oracle.com> (raw)
In-Reply-To: <20180518062430.GB21711@dhcp22.suse.cz>
On 05/17/2018 11:24 PM, Michal Hocko wrote:
> On Fri 18-05-18 11:03:16, Huang, Ying wrote:
> [...]
>> The patch is a generic optimization which should benefit quite some
>> workloads, not for a specific use case. To demonstrate the performance
>> benefit of the patch, we tested it with vm-scalability run on
>> transparent huge page.
>
> It is also adds quite some non-intuitive code. So is this worth? Does
> any _real_ workload benefits from the change?
One way to 'add less code' would be to create a helper routine that
indicates the order in which sub-pages are to be copied. IIUC, you
added the same algorithm for sub-page ordering to copy_huge_page()
that was previously added to clear_huge_page(). Correct? If so,
then perhaps a common helper could be used by both the clear and copy
huge page routines. It would also make maintenance easier.
--
Mike Kravetz
next prev parent reply other threads:[~2018-05-18 16:41 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-18 3:03 [PATCH -mm] mm, huge page: Copy to access sub-page last when copy huge page Huang, Ying
2018-05-18 6:24 ` Michal Hocko
2018-05-18 16:41 ` Mike Kravetz [this message]
2018-05-21 2:34 ` Huang, Ying
2018-05-21 1:51 ` Huang, Ying
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