From: Bruce Richardson <bruce.richardson@intel.com>
To: "Morten Brørup" <mb@smartsharesystems.com>
Cc: Dharmik Thakkar <dharmik.thakkar@arm.com>,
dev@dpdk.org, nd@arm.com, honnappa.nagarahalli@arm.com,
ruifeng.wang@arm.com
Subject: Re: [PATCH 0/1] mempool: implement index-based per core cache
Date: Fri, 7 Jan 2022 11:15:57 +0000 [thread overview]
Message-ID: <Ydgg7YlndpBb0g+w@bricha3-MOBL.ger.corp.intel.com> (raw)
In-Reply-To: <98CBD80474FA8B44BF855DF32C47DC35D86DAD@smartserver.smartshare.dk>
On Sat, Dec 25, 2021 at 01:16:03AM +0100, Morten Brørup wrote:
> > From: Dharmik Thakkar [mailto:dharmik.thakkar@arm.com] Sent: Friday, 24
> > December 2021 23.59
> >
> > Current mempool per core cache implementation stores pointers to mbufs
> > On 64b architectures, each pointer consumes 8B This patch replaces it
> > with index-based implementation, where in each buffer is addressed by
> > (pool base address + index) It reduces the amount of memory/cache
> > required for per core cache
> >
> > L3Fwd performance testing reveals minor improvements in the cache
> > performance (L1 and L2 misses reduced by 0.60%) with no change in
> > throughput
> >
> > Micro-benchmarking the patch using mempool_perf_test shows significant
> > improvement with majority of the test cases
> >
> > Number of cores = 1: n_get_bulk=1 n_put_bulk=1 n_keep=32
> > %_change_with_patch=18.01 n_get_bulk=1 n_put_bulk=1 n_keep=128
> > %_change_with_patch=19.91 n_get_bulk=1 n_put_bulk=4 n_keep=32
> > %_change_with_patch=-20.37 (regression) n_get_bulk=1 n_put_bulk=4
> > n_keep=128 %_change_with_patch=-17.01 (regression) n_get_bulk=1
> > n_put_bulk=32 n_keep=32 %_change_with_patch=-25.06 (regression)
> > n_get_bulk=1 n_put_bulk=32 n_keep=128 %_change_with_patch=-23.81
> > (regression) n_get_bulk=4 n_put_bulk=1 n_keep=32
> > %_change_with_patch=53.93 n_get_bulk=4 n_put_bulk=1 n_keep=128
> > %_change_with_patch=60.90 n_get_bulk=4 n_put_bulk=4 n_keep=32
> > %_change_with_patch=1.64 n_get_bulk=4 n_put_bulk=4 n_keep=128
> > %_change_with_patch=8.76 n_get_bulk=4 n_put_bulk=32 n_keep=32
> > %_change_with_patch=-4.71 (regression) n_get_bulk=4 n_put_bulk=32
> > n_keep=128 %_change_with_patch=-3.19 (regression) n_get_bulk=32
> > n_put_bulk=1 n_keep=32 %_change_with_patch=65.63 n_get_bulk=32
> > n_put_bulk=1 n_keep=128 %_change_with_patch=75.19 n_get_bulk=32
> > n_put_bulk=4 n_keep=32 %_change_with_patch=11.75 n_get_bulk=32
> > n_put_bulk=4 n_keep=128 %_change_with_patch=15.52 n_get_bulk=32
> > n_put_bulk=32 n_keep=32 %_change_with_patch=13.45 n_get_bulk=32
> > n_put_bulk=32 n_keep=128 %_change_with_patch=11.58
> >
> > Number of core = 2: n_get_bulk=1 n_put_bulk=1 n_keep=32
> > %_change_with_patch=18.21 n_get_bulk=1 n_put_bulk=1 n_keep=128
> > %_change_with_patch=21.89 n_get_bulk=1 n_put_bulk=4 n_keep=32
> > %_change_with_patch=-21.21 (regression) n_get_bulk=1 n_put_bulk=4
> > n_keep=128 %_change_with_patch=-17.05 (regression) n_get_bulk=1
> > n_put_bulk=32 n_keep=32 %_change_with_patch=-26.09 (regression)
> > n_get_bulk=1 n_put_bulk=32 n_keep=128 %_change_with_patch=-23.49
> > (regression) n_get_bulk=4 n_put_bulk=1 n_keep=32
> > %_change_with_patch=56.28 n_get_bulk=4 n_put_bulk=1 n_keep=128
> > %_change_with_patch=67.69 n_get_bulk=4 n_put_bulk=4 n_keep=32
> > %_change_with_patch=1.45 n_get_bulk=4 n_put_bulk=4 n_keep=128
> > %_change_with_patch=8.84 n_get_bulk=4 n_put_bulk=32 n_keep=32
> > %_change_with_patch=-5.27 (regression) n_get_bulk=4 n_put_bulk=32
> > n_keep=128 %_change_with_patch=-3.09 (regression) n_get_bulk=32
> > n_put_bulk=1 n_keep=32 %_change_with_patch=76.11 n_get_bulk=32
> > n_put_bulk=1 n_keep=128 %_change_with_patch=86.06 n_get_bulk=32
> > n_put_bulk=4 n_keep=32 %_change_with_patch=11.86 n_get_bulk=32
> > n_put_bulk=4 n_keep=128 %_change_with_patch=16.55 n_get_bulk=32
> > n_put_bulk=32 n_keep=32 %_change_with_patch=13.01 n_get_bulk=32
> > n_put_bulk=32 n_keep=128 %_change_with_patch=11.51
> >
> >
> > From analyzing the results, it is clear that for n_get_bulk and
> > n_put_bulk sizes of 32 there is no performance regression IMO, the
> > other sizes are not practical from performance perspective and the
> > regression in those cases can be safely ignored
> >
> > Dharmik Thakkar (1): mempool: implement index-based per core cache
> >
> > lib/mempool/rte_mempool.h | 114 +++++++++++++++++++++++++-
> > lib/mempool/rte_mempool_ops_default.c | 7 ++ 2 files changed, 119
> > insertions(+), 2 deletions(-)
> >
> > -- 2.25.1
> >
>
> I still think this is very interesting. And your performance numbers are
> looking good.
>
> However, it limits the size of a mempool to 4 GB. As previously
> discussed, the max mempool size can be increased by multiplying the index
> with a constant.
>
> I would suggest using sizeof(uintptr_t) as the constant multiplier, so
> the mempool can hold objects of any size divisible by sizeof(uintptr_t).
> And it would be silly to use a mempool to hold objects smaller than
> sizeof(uintptr_t).
>
> How does the performance look if you multiply the index by
> sizeof(uintptr_t)?
>
Each mempool entry is cache aligned, so we can use that if we want a bigger
multiplier.
next prev parent reply other threads:[~2022-01-07 11:16 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-30 17:27 [dpdk-dev] [RFC] " Dharmik Thakkar
2021-10-01 12:36 ` Jerin Jacob
2021-10-01 15:44 ` Honnappa Nagarahalli
2021-10-01 17:32 ` Jerin Jacob
2021-10-01 17:57 ` Honnappa Nagarahalli
2021-10-01 18:21 ` Jerin Jacob
2021-10-01 21:30 ` Ananyev, Konstantin
2021-10-02 0:07 ` Honnappa Nagarahalli
2021-10-02 18:51 ` Ananyev, Konstantin
2021-10-04 16:36 ` Honnappa Nagarahalli
2021-10-30 10:23 ` Morten Brørup
2021-10-31 8:14 ` Morten Brørup
2021-11-03 15:12 ` Dharmik Thakkar
2021-11-03 15:52 ` Morten Brørup
2021-11-04 4:42 ` Dharmik Thakkar
2021-11-04 8:04 ` Morten Brørup
2021-11-08 4:32 ` Honnappa Nagarahalli
2021-11-08 7:22 ` Morten Brørup
2021-11-08 15:29 ` Honnappa Nagarahalli
2021-11-08 15:39 ` Morten Brørup
2021-11-08 15:46 ` Honnappa Nagarahalli
2021-11-08 16:03 ` Morten Brørup
2021-11-08 16:47 ` Jerin Jacob
2021-12-24 22:59 ` [PATCH 0/1] " Dharmik Thakkar
2021-12-24 22:59 ` [PATCH 1/1] " Dharmik Thakkar
2022-01-11 2:26 ` Ananyev, Konstantin
2022-01-13 5:17 ` Dharmik Thakkar
2022-01-13 10:37 ` Ananyev, Konstantin
2022-01-19 15:32 ` Dharmik Thakkar
2022-01-21 11:25 ` Ananyev, Konstantin
2022-01-21 11:31 ` Ananyev, Konstantin
2022-03-24 19:51 ` Dharmik Thakkar
2021-12-25 0:16 ` [PATCH 0/1] " Morten Brørup
2022-01-07 11:15 ` Bruce Richardson [this message]
2022-01-07 11:29 ` Morten Brørup
2022-01-07 13:50 ` Bruce Richardson
2022-01-08 9:37 ` Morten Brørup
2022-01-10 6:38 ` Jerin Jacob
2022-01-13 5:31 ` Dharmik Thakkar
2023-07-06 17:43 ` Stephen Hemminger
2023-07-31 12:23 ` Thomas Monjalon
2023-07-31 12:33 ` Morten Brørup
2023-07-31 14:57 ` Dharmik Jayesh Thakkar
2022-01-13 5:36 ` [PATCH v2 " Dharmik Thakkar
2022-01-13 5:36 ` [PATCH v2 1/1] " Dharmik Thakkar
2022-01-13 10:18 ` Jerin Jacob
2022-01-20 8:21 ` Morten Brørup
2022-01-21 6:01 ` Honnappa Nagarahalli
2022-01-21 7:36 ` Morten Brørup
2022-01-24 13:05 ` Ray Kinsella
2022-01-21 9:12 ` Bruce Richardson
2022-01-23 7:13 ` Wang, Haiyue
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