From: Alexander Duyck <alexander.duyck@gmail.com>
To: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Josh Triplett <josh@joshtriplett.org>,
Andrew Morton <akpm@linux-foundation.org>,
Herbert Xu <herbert@gondor.apana.org.au>,
Steffen Klassert <steffen.klassert@secunet.com>,
Alex Williamson <alex.williamson@redhat.com>,
Alexander Duyck <alexander.h.duyck@linux.intel.com>,
Dan Williams <dan.j.williams@intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
David Hildenbrand <david@redhat.com>,
Jason Gunthorpe <jgg@ziepe.ca>, Jonathan Corbet <corbet@lwn.net>,
Kirill Tkhai <ktkhai@virtuozzo.com>,
Michal Hocko <mhocko@kernel.org>, Pavel Machek <pavel@ucw.cz>,
Pavel Tatashin <pasha.tatashin@soleen.com>,
Peter Zijlstra <peterz@infradead.org>,
Randy Dunlap <rdunlap@infradead.org>,
Shile Zhang <shile.zhang@linux.alibaba.com>,
Tejun Heo <tj@kernel.org>, Zi Yan <ziy@nvidia.com>,
linux-crypto@vger.kernel.org, linux-mm <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 6/7] mm: parallelize deferred_init_memmap()
Date: Tue, 5 May 2020 07:55:43 -0700 [thread overview]
Message-ID: <CAKgT0UdE1ex_aAyMeR3PWtVcmXL8cUtjqy0J8hLpnFm42yn82w@mail.gmail.com> (raw)
In-Reply-To: <20200505020916.mve4ijrg4z5h7eh5@ca-dmjordan1.us.oracle.com>
On Mon, May 4, 2020 at 7:11 PM Daniel Jordan <daniel.m.jordan@oracle.com> wrote:
>
> On Mon, May 04, 2020 at 09:48:44PM -0400, Daniel Jordan wrote:
> > On Mon, May 04, 2020 at 05:40:19PM -0700, Alexander Duyck wrote:
> > > On Mon, May 4, 2020 at 4:44 PM Josh Triplett <josh@joshtriplett.org> wrote:
> > > >
> > > > On May 4, 2020 3:33:58 PM PDT, Alexander Duyck <alexander.duyck@gmail.com> wrote:
> > > > >On Thu, Apr 30, 2020 at 1:12 PM Daniel Jordan
> > > > ><daniel.m.jordan@oracle.com> wrote:
> > > > >> /*
> > > > >> - * Initialize and free pages in MAX_ORDER sized increments so
> > > > >> - * that we can avoid introducing any issues with the buddy
> > > > >> - * allocator.
> > > > >> + * More CPUs always led to greater speedups on tested
> > > > >systems, up to
> > > > >> + * all the nodes' CPUs. Use all since the system is
> > > > >otherwise idle now.
> > > > >> */
> > > > >
> > > > >I would be curious about your data. That isn't what I have seen in the
> > > > >past. Typically only up to about 8 or 10 CPUs gives you any benefit,
> > > > >beyond that I was usually cache/memory bandwidth bound.
> >
> > On Skylake it took more than 8 or 10 CPUs, though on other machines the benefit
> > of using all versus half or 3/4 of the CPUs is less significant.
> >
> > Given that the rest of the system is idle at this point, my main concern is
> > whether other archs regress past a certain thread count.
>
> Reposting the data to be consistent with the way the percentages are reported
> in the changelog.
>
>
> Intel(R) Xeon(R) Platinum 8167M CPU @ 2.00GHz (Skylake, bare metal)
> 2 nodes * 26 cores * 2 threads = 104 CPUs
> 384G/node = 768G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 4056.7 ( 5.5) -- 1763.3 ( 4.2)
> 2% ( 1) -2.4% 4153.3 ( 2.5) -5.6% 1861.7 ( 5.5)
> 12% ( 6) 35.0% 2637.7 ( 38.7) 80.3% 346.7 ( 37.5)
> 25% ( 13) 38.4% 2497.3 ( 38.5) 88.1% 210.0 ( 41.8)
> 37% ( 19) 38.9% 2477.0 ( 19.0) 89.5% 185.3 ( 21.5)
> 50% ( 26) 39.1% 2471.7 ( 21.4) 89.8% 179.7 ( 25.8)
> 75% ( 39) 39.5% 2455.7 ( 33.2) 90.8% 161.7 ( 29.3)
> 100% ( 52) 39.9% 2436.7 ( 2.1) 91.8% 144.3 ( 5.9)
>
>
> Intel(R) Xeon(R) CPU E5-2699C v4 @ 2.20GHz (Broadwell, bare metal)
> 1 node * 16 cores * 2 threads = 32 CPUs
> 192G/node = 192G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 1957.3 ( 14.0) -- 1093.7 ( 12.9)
> 3% ( 1) 1.4% 1930.7 ( 10.0) 3.7% 1053.3 ( 7.6)
> 12% ( 4) 41.2% 1151.7 ( 9.0) 74.5% 278.7 ( 0.6)
> 25% ( 8) 46.3% 1051.0 ( 7.8) 83.7% 178.0 ( 2.6)
> 38% ( 12) 48.7% 1003.3 ( 7.6) 87.0% 141.7 ( 3.8)
> 50% ( 16) 48.2% 1014.3 ( 20.0) 87.8% 133.3 ( 3.2)
> 75% ( 24) 49.5% 989.3 ( 6.7) 88.4% 126.3 ( 1.5)
> 100% ( 32) 49.1% 996.0 ( 7.2) 88.4% 127.3 ( 5.1)
>
>
> Intel(R) Xeon(R) CPU E5-2699 v3 @ 2.30GHz (Haswell, bare metal)
> 2 nodes * 18 cores * 2 threads = 72 CPUs
> 128G/node = 256G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 1666.0 ( 3.5) -- 618.0 ( 3.5)
> 3% ( 1) 1.0% 1649.7 ( 1.5) 2.9% 600.0 ( 1.0)
> 11% ( 4) 25.9% 1234.7 ( 21.4) 70.4% 183.0 ( 22.5)
> 25% ( 9) 29.6% 1173.0 ( 10.0) 80.7% 119.3 ( 9.6)
> 36% ( 13) 30.8% 1153.7 ( 17.0) 84.0% 99.0 ( 15.6)
> 50% ( 18) 31.0% 1150.3 ( 15.5) 84.3% 97.3 ( 16.2)
> 75% ( 27) 31.0% 1150.3 ( 2.5) 84.6% 95.0 ( 5.6)
> 100% ( 36) 31.3% 1145.3 ( 1.5) 85.6% 89.0 ( 1.7)
>
>
> AMD EPYC 7551 32-Core Processor (Zen, kvm guest)
> 1 node * 8 cores * 2 threads = 16 CPUs
> 64G/node = 64G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 1029.7 ( 42.3) -- 253.7 ( 3.1)
> 6% ( 1) 3.3% 995.3 ( 21.4) 4.3% 242.7 ( 5.5)
> 12% ( 2) 14.0% 885.7 ( 24.4) 46.4% 136.0 ( 5.2)
> 25% ( 4) 18.9% 835.0 ( 21.5) 66.1% 86.0 ( 1.7)
> 38% ( 6) 21.9% 804.7 ( 15.7) 71.4% 72.7 ( 2.1)
> 50% ( 8) 20.8% 815.3 ( 11.7) 74.4% 65.0 ( 3.5)
> 75% ( 12) 23.5% 787.7 ( 2.1) 74.0% 66.0 ( 3.6)
> 100% ( 16) 23.3% 789.3 ( 15.0) 76.3% 60.0 ( 5.6)
>
>
> AMD EPYC 7551 32-Core Processor (Zen, kvm guest)
> 1 node * 2 cores * 2 threads = 4 CPUs
> 16G/node = 16G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 757.7 ( 17.1) -- 57.0 ( 0.0)
> 25% ( 1) -1.0% 765.3 ( 5.5) 3.5% 55.0 ( 0.0)
> 50% ( 2) 4.7% 722.3 ( 21.5) 42.7% 32.7 ( 4.6)
> 75% ( 3) 3.7% 729.7 ( 4.9) 54.4% 26.0 ( 0.0)
> 100% ( 4) 6.2% 710.3 ( 15.0) 63.2% 21.0 ( 0.0)
>
>
> Intel(R) Xeon(R) CPU E5-2699 v3 @ 2.30GHz (Haswell, kvm guest)
> 1 node * 2 cores * 2 threads = 4 CPUs
> 14G/node = 14G memory
>
> kernel boot deferred init
> ------------------------ ------------------------
> node% (thr) speedup time_ms (stdev) speedup time_ms (stdev)
> ( 0) -- 656.3 ( 7.1) -- 57.3 ( 1.5)
> 25% ( 1) 1.8% 644.7 ( 3.1) 0.6% 57.0 ( 0.0)
> 50% ( 2) 6.5% 613.7 ( 5.1) 40.7% 34.0 ( 5.3)
> 75% ( 3) 6.9% 611.3 ( 6.7) 57.6% 24.3 ( 0.6)
> 100% ( 4) 8.6% 599.7 ( 5.9) 62.8% 21.3 ( 1.2)
One question about this data. What is the power management
configuration on the systems when you are running these tests? I'm
just curious if CPU frequency scaling, C states, and turbo are
enabled? I ask because that is what I have seen usually make the
difference in these kind of workloads as the throughput starts
dropping off as you start seeing the core frequency lower and more
cores become active.
next prev parent reply other threads:[~2020-05-05 14:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-30 20:11 [PATCH 0/7] padata: parallelize deferred page init Daniel Jordan
2020-04-30 20:11 ` [PATCH 1/7] padata: remove exit routine Daniel Jordan
2020-04-30 20:11 ` [PATCH 2/7] padata: initialize earlier Daniel Jordan
2020-04-30 20:11 ` [PATCH 3/7] padata: allocate work structures for parallel jobs from a pool Daniel Jordan
2020-04-30 20:11 ` [PATCH 4/7] padata: add basic support for multithreaded jobs Daniel Jordan
2020-04-30 20:11 ` [PATCH 5/7] mm: move zone iterator outside of deferred_init_maxorder() Daniel Jordan
2020-04-30 21:43 ` Alexander Duyck
2020-05-01 2:45 ` Daniel Jordan
2020-05-04 22:10 ` Alexander Duyck
2020-05-04 22:10 ` Alexander Duyck
2020-05-05 0:54 ` Daniel Jordan
2020-05-05 15:27 ` Alexander Duyck
2020-05-05 15:27 ` Alexander Duyck
2020-05-06 22:39 ` Daniel Jordan
2020-05-07 15:26 ` Alexander Duyck
2020-05-07 15:26 ` Alexander Duyck
2020-05-07 20:20 ` Daniel Jordan
2020-05-07 21:18 ` Alexander Duyck
2020-05-07 21:18 ` Alexander Duyck
2020-05-07 22:15 ` Daniel Jordan
2020-04-30 20:11 ` [PATCH 6/7] mm: parallelize deferred_init_memmap() Daniel Jordan
2020-05-04 22:33 ` Alexander Duyck
2020-05-04 22:33 ` Alexander Duyck
2020-05-04 23:38 ` Josh Triplett
2020-05-04 23:38 ` Josh Triplett
2020-05-05 0:40 ` Alexander Duyck
2020-05-05 0:40 ` Alexander Duyck
2020-05-05 1:48 ` Daniel Jordan
2020-05-05 2:09 ` Daniel Jordan
2020-05-05 14:55 ` Alexander Duyck [this message]
2020-05-05 14:55 ` Alexander Duyck
2020-05-06 22:21 ` Daniel Jordan
2020-05-06 22:36 ` Alexander Duyck
2020-05-06 22:36 ` Alexander Duyck
2020-05-06 22:43 ` Daniel Jordan
2020-05-06 23:01 ` Daniel Jordan
2020-05-05 1:26 ` Daniel Jordan
2020-04-30 20:11 ` [PATCH 7/7] padata: document multithreaded jobs Daniel Jordan
2020-04-30 21:31 ` [PATCH 0/7] padata: parallelize deferred page init Andrew Morton
2020-04-30 21:40 ` Pavel Tatashin
2020-04-30 21:40 ` Pavel Tatashin
2020-05-01 2:40 ` Daniel Jordan
2020-05-01 0:50 ` Josh Triplett
2020-05-01 1:09 ` Josh Triplett
2020-05-01 2:48 ` Daniel Jordan
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