From: K Prateek Nayak <kprateek.nayak@amd.com>
To: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: peterz@infradead.org, bristot@redhat.com, bsegall@google.com,
chris.hyser@oracle.com, corbet@lwn.net, dietmar.eggemann@arm.com,
efault@gmx.de, joel@joelfernandes.org, joshdon@google.com,
juri.lelli@redhat.com, linux-kernel@vger.kernel.org,
mgorman@suse.de, mingo@kernel.org, patrick.bellasi@matbug.net,
pavel@ucw.cz, pjt@google.com, qperret@google.com,
qyousef@layalina.io, rostedt@goodmis.org, tglx@linutronix.de,
tim.c.chen@linux.intel.com, timj@gnu.org,
vincent.guittot@linaro.org, youssefesmat@chromium.org,
yu.c.chen@intel.com
Subject: Re: [PATCH] sched/fair: Always update_curr() before placing at enqueue
Date: Mon, 16 Oct 2023 11:09:11 +0530 [thread overview]
Message-ID: <1878eaa4-0d2b-933a-12c8-40b28d771251@amd.com> (raw)
In-Reply-To: <20231006164826.335223-1-daniel.m.jordan@oracle.com>
Hello Daniel,
I see a good and consistent improvement in Stream (with shorter loops)
with this change. Everything else is more or less the same.
I'll leave the detailed results below.
On 10/6/2023 10:18 PM, Daniel Jordan wrote:
> Placing wants current's vruntime and the cfs_rq's min_vruntime up to
> date so that avg_runtime() is too, and similarly it wants the entity to
> be re-weighted and lag adjusted so vslice and vlag are fresh, so always
> do update_curr() and update_cfs_group() beforehand.
>
> There doesn't seem to be a reason to treat the 'curr' case specially
> after e8f331bcc270 since vruntime doesn't get normalized anymore.
>
> Fixes: e8f331bcc270 ("sched/smp: Use lag to simplify cross-runqueue placement")
> Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
o Machine details
- 3rd Generation EPYC System
- 2 sockets each with 64C/128T
- NPS1 (Each socket is a NUMA node)
- C2 Disabled (POLL and C1(MWAIT) remained enabled)
o Kernel Details
- tip: tip:sched/core at commit 3657680f38cd ("sched/psi: Delete the
'update_total' function parameter from update_triggers()") +
cherry-pick commit 8dafa9d0eb1a sched/eevdf: Fix min_deadline heap
integrity") from tip:sched/urgent + cherry-pick commit b01db23d5923
("sched/eevdf: Fix pick_eevdf()") from tip:sched/urgent
update_curr_opt: tip + this patch
o Benchmark Results
==================================================================
Test : hackbench
Units : Normalized time in seconds
Interpretation: Lower is better
Statistic : AMean
==================================================================
Case: tip[pct imp](CV) update_curr_opt[pct imp](CV)
1-groups 1.00 [ -0.00]( 2.69) 1.01 [ -0.71]( 2.88)
2-groups 1.00 [ -0.00]( 1.69) 1.01 [ -0.62]( 1.40)
4-groups 1.00 [ -0.00]( 1.25) 1.01 [ -1.17]( 1.03)
8-groups 1.00 [ -0.00]( 1.36) 1.00 [ -0.43]( 0.83)
16-groups 1.00 [ -0.00]( 1.44) 1.00 [ -0.13]( 2.32)
==================================================================
Test : tbench
Units : Normalized throughput
Interpretation: Higher is better
Statistic : AMean
==================================================================
Clients: tip[pct imp](CV) update_curr_opt[pct imp](CV)
1 1.00 [ 0.00]( 0.33) 1.01 [ 0.52]( 1.51)
2 1.00 [ 0.00]( 0.22) 1.00 [ -0.01]( 0.37)
4 1.00 [ 0.00]( 0.25) 0.99 [ -0.71]( 0.60)
8 1.00 [ 0.00]( 0.71) 1.00 [ -0.26]( 0.36)
16 1.00 [ 0.00]( 0.79) 0.99 [ -1.21]( 0.77)
32 1.00 [ 0.00]( 0.94) 0.99 [ -0.82]( 1.46)
64 1.00 [ 0.00]( 1.76) 0.99 [ -0.92]( 1.25)
128 1.00 [ 0.00]( 0.68) 0.98 [ -2.22]( 1.19)
256 1.00 [ 0.00]( 1.23) 0.99 [ -1.43]( 0.79)
512 1.00 [ 0.00]( 0.28) 0.99 [ -0.93]( 0.14)
1024 1.00 [ 0.00]( 0.20) 0.99 [ -1.44]( 0.41)
==================================================================
Test : stream-10
Units : Normalized Bandwidth, MB/s
Interpretation: Higher is better
Statistic : HMean
==================================================================
Test: tip[pct imp](CV) update_curr_opt[pct imp](CV)
Copy 1.00 [ 0.00](11.88) 1.22 [ 21.92]( 7.37)
Scale 1.00 [ 0.00]( 7.01) 1.04 [ 4.02]( 4.89)
Add 1.00 [ 0.00]( 6.56) 1.11 [ 11.03]( 4.77)
Triad 1.00 [ 0.00]( 8.81) 1.14 [ 14.12]( 3.89)
==================================================================
Test : stream-100
Units : Normalized Bandwidth, MB/s
Interpretation: Higher is better
Statistic : HMean
==================================================================
Test: tip[pct imp](CV) update_curr_opt[pct imp](CV)
Copy 1.00 [ 0.00]( 1.07) 1.01 [ 0.77]( 1.59)
Scale 1.00 [ 0.00]( 4.81) 0.97 [ -2.99]( 7.18)
Add 1.00 [ 0.00]( 4.56) 0.98 [ -2.39]( 6.86)
Triad 1.00 [ 0.00]( 1.78) 1.00 [ -0.35]( 4.22)
==================================================================
Test : netperf
Units : Normalized Througput
Interpretation: Higher is better
Statistic : AMean
==================================================================
Clients: tip[pct imp](CV) update_curr_opt[pct imp](CV)
1-clients 1.00 [ 0.00]( 0.62) 0.99 [ -1.03]( 0.24)
2-clients 1.00 [ 0.00]( 0.36) 1.00 [ -0.32]( 0.66)
4-clients 1.00 [ 0.00]( 0.31) 1.00 [ -0.17]( 0.44)
8-clients 1.00 [ 0.00]( 0.39) 1.00 [ 0.24]( 0.67)
16-clients 1.00 [ 0.00]( 0.58) 1.00 [ 0.50]( 0.46)
32-clients 1.00 [ 0.00]( 0.71) 1.01 [ 0.54]( 0.66)
64-clients 1.00 [ 0.00]( 2.13) 1.00 [ 0.35]( 1.80)
128-clients 1.00 [ 0.00]( 0.94) 0.99 [ -0.71]( 0.97)
256-clients 1.00 [ 0.00]( 6.09) 1.01 [ 1.28]( 3.41)
512-clients 1.00 [ 0.00](55.28) 1.01 [ 1.32](49.78)
==================================================================
Test : schbench
Units : Normalized 99th percentile latency in us
Interpretation: Lower is better
Statistic : Median
==================================================================
#workers: tip[pct imp](CV) update_curr_opt[pct imp](CV)
1 1.00 [ -0.00]( 2.91) 0.97 [ 2.56]( 1.53)
2 1.00 [ -0.00](21.78) 0.89 [ 10.53](10.23)
4 1.00 [ -0.00]( 4.88) 1.07 [ -7.32]( 6.82)
8 1.00 [ -0.00]( 2.49) 1.00 [ -0.00]( 9.53)
16 1.00 [ -0.00]( 3.70) 1.02 [ -1.75]( 0.99)
32 1.00 [ -0.00](12.65) 0.83 [ 16.51]( 4.41)
64 1.00 [ -0.00]( 3.98) 0.97 [ 2.59]( 8.27)
128 1.00 [ -0.00]( 1.49) 0.96 [ 3.60]( 8.01)
256 1.00 [ -0.00](40.79) 0.80 [ 20.39](36.89)
512 1.00 [ -0.00]( 1.12) 0.98 [ 2.20]( 0.75)
==================================================================
Test : ycsb-cassandra
Units : Normalized throughput
Interpretation: Higher is better
Statistic : Mean
==================================================================
metric tip update_curr_opt (%diff)
throughput 1.00 1.00 (%diff: -0.45%)
==================================================================
Test : ycsb-mondodb
Units : Normalized throughput
Interpretation: Higher is better
Statistic : Mean
==================================================================
metric tip update_curr_opt (%diff)
throughput 1.00 1.00 (%diff: -0.13%)
==================================================================
Test : DeathStarBench
Units : Normalized throughput
Interpretation: Higher is better
Statistic : Mean
==================================================================
Pinning scaling tip update_curr_opt (%diff)
1CCD 1 1.00 1.01 (%diff: 0.57%)
2CCD 2 1.00 1.00 (%diff: -0.27%)
4CCD 4 1.00 1.00 (%diff: 0.06%)
8CCD 8 1.00 1.00 (%diff: 0.45%)
--
Feel free to include
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
I'll keep a lookout for future versions.
> ---
>
> Not sure what the XXX above place_entity() is for, maybe it can go away?
>
> Based on tip/sched/core.
>
> kernel/sched/fair.c | 14 ++------------
> 1 file changed, 2 insertions(+), 12 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 04fbcbda97d5f..db2ca9bf9cc49 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5047,15 +5047,6 @@ static inline bool cfs_bandwidth_used(void);
> static void
> enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
> {
> - bool curr = cfs_rq->curr == se;
> -
> - /*
> - * If we're the current task, we must renormalise before calling
> - * update_curr().
> - */
> - if (curr)
> - place_entity(cfs_rq, se, flags);
> -
> update_curr(cfs_rq);
>
> /*
> @@ -5080,8 +5071,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
> * XXX now that the entity has been re-weighted, and it's lag adjusted,
> * we can place the entity.
> */
> - if (!curr)
> - place_entity(cfs_rq, se, flags);
> + place_entity(cfs_rq, se, flags);
>
> account_entity_enqueue(cfs_rq, se);
>
> @@ -5091,7 +5081,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
>
> check_schedstat_required();
> update_stats_enqueue_fair(cfs_rq, se, flags);
> - if (!curr)
> + if (cfs_rq->curr != se)
> __enqueue_entity(cfs_rq, se);
> se->on_rq = 1;
>
--
Thanks and Regards,
Prateek
next prev parent reply other threads:[~2023-10-16 5:39 UTC|newest]
Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 11:58 [PATCH 00/15] sched: EEVDF and latency-nice and/or slice-attr Peter Zijlstra
2023-05-31 11:58 ` [PATCH 01/15] sched/fair: Add avg_vruntime Peter Zijlstra
2023-06-02 13:51 ` Vincent Guittot
2023-06-02 14:27 ` Peter Zijlstra
2023-06-05 7:18 ` Vincent Guittot
2023-08-10 7:10 ` [tip: sched/core] sched/fair: Add cfs_rq::avg_vruntime tip-bot2 for Peter Zijlstra
2023-10-11 4:15 ` [PATCH 01/15] sched/fair: Add avg_vruntime Abel Wu
2023-10-11 7:30 ` Peter Zijlstra
2023-10-11 8:30 ` Abel Wu
2023-10-11 9:45 ` Peter Zijlstra
2023-10-11 10:05 ` Peter Zijlstra
2023-10-11 13:08 ` Peter Zijlstra
2023-05-31 11:58 ` [PATCH 02/15] sched/fair: Remove START_DEBIT Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] sched/fair: Remove sched_feat(START_DEBIT) tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 03/15] sched/fair: Add lag based placement Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2023-10-11 12:00 ` [PATCH 03/15] " Abel Wu
2023-10-11 13:24 ` Peter Zijlstra
2023-10-12 7:04 ` Abel Wu
2023-10-13 7:37 ` Peter Zijlstra
2023-10-13 8:14 ` Abel Wu
2023-10-12 19:15 ` Benjamin Segall
2023-10-12 22:34 ` Peter Zijlstra
2023-10-13 16:35 ` Peter Zijlstra
2023-10-14 8:08 ` Mike Galbraith
2023-10-13 14:34 ` Peter Zijlstra
2025-02-07 10:07 ` Breno Leitao
2025-02-07 11:11 ` Peter Zijlstra
2025-02-07 12:25 ` Breno Leitao
2025-02-07 12:30 ` Peter Zijlstra
2025-02-07 13:22 ` Breno Leitao
2025-02-07 13:38 ` Breno Leitao
2025-02-07 13:39 ` Vincent Guittot
2025-02-14 17:21 ` Breno Leitao
2023-05-31 11:58 ` [PATCH 04/15] rbtree: Add rb_add_augmented_cached() helper Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 05/15] sched/fair: Implement an EEVDF like policy Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] sched/fair: Implement an EEVDF-like scheduling policy tip-bot2 for Peter Zijlstra
2023-09-29 21:40 ` [PATCH 05/15] sched/fair: Implement an EEVDF like policy Benjamin Segall
2023-10-02 17:39 ` Peter Zijlstra
2023-10-11 4:14 ` Abel Wu
2023-10-11 7:33 ` Peter Zijlstra
2023-10-11 11:49 ` Abel Wu
2023-09-30 0:09 ` [PATCH] sched/fair: fix pick_eevdf to always find the correct se Benjamin Segall
2023-10-03 10:42 ` [tip: sched/urgent] sched/fair: Fix pick_eevdf() tip-bot2 for Benjamin Segall
[not found] ` <CGME20231004203940eucas1p2f73b017497d1f4239a6e236fdb6019e2@eucas1p2.samsung.com>
2023-10-04 20:39 ` [PATCH] sched/fair: fix pick_eevdf to always find the correct se Marek Szyprowski
2023-10-09 7:53 ` [tip: sched/urgent] sched/eevdf: Fix pick_eevdf() tip-bot2 for Benjamin Segall
2023-10-11 12:12 ` [PATCH] sched/fair: fix pick_eevdf to always find the correct se Abel Wu
2023-10-11 13:14 ` Peter Zijlstra
2023-10-12 10:04 ` Abel Wu
2023-10-11 21:01 ` Benjamin Segall
2023-10-12 10:25 ` Abel Wu
2023-10-12 17:51 ` Benjamin Segall
2023-10-13 3:46 ` Abel Wu
2023-10-13 16:51 ` Benjamin Segall
2023-05-31 11:58 ` [PATCH 06/15] sched: Commit to lag based placement Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] sched/fair: " tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 07/15] sched/smp: Use lag to simplify cross-runqueue placement Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2023-09-12 15:32 ` [PATCH 07/15] " Sebastian Andrzej Siewior
2023-09-13 9:03 ` Peter Zijlstra
2023-10-04 1:17 ` [PATCH] sched/fair: Preserve PLACE_DEADLINE_INITIAL deadline Daniel Jordan
2023-10-04 13:09 ` [PATCH v2] " Daniel Jordan
2023-10-04 15:46 ` Chen Yu
2023-10-06 16:31 ` Daniel Jordan
2023-10-12 4:48 ` K Prateek Nayak
2023-10-05 5:56 ` [PATCH] " K Prateek Nayak
2023-10-06 16:35 ` Daniel Jordan
2023-10-06 16:48 ` [PATCH] sched/fair: Always update_curr() before placing at enqueue Daniel Jordan
2023-10-06 19:58 ` Peter Zijlstra
2023-10-18 0:43 ` Daniel Jordan
2023-10-16 5:39 ` K Prateek Nayak [this message]
2023-05-31 11:58 ` [PATCH 08/15] sched: Commit to EEVDF Peter Zijlstra
2023-06-16 21:23 ` Joel Fernandes
2023-06-22 12:01 ` Ingo Molnar
2023-06-22 13:11 ` Joel Fernandes
2023-08-10 7:10 ` [tip: sched/core] sched/fair: " tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 09/15] sched/debug: Rename min_granularity to base_slice Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] sched/debug: Rename sysctl_sched_min_granularity to sysctl_sched_base_slice tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 10/15] sched/fair: Propagate enqueue flags into place_entity() Peter Zijlstra
2023-08-10 7:10 ` [tip: sched/core] " tip-bot2 for Peter Zijlstra
2023-05-31 11:58 ` [PATCH 11/15] sched/eevdf: Better handle mixed slice length Peter Zijlstra
2023-06-02 13:45 ` Vincent Guittot
2023-06-02 15:06 ` Peter Zijlstra
2023-06-10 6:34 ` Chen Yu
2023-06-10 11:22 ` Peter Zijlstra
2023-05-31 11:58 ` [RFC][PATCH 12/15] sched: Introduce latency-nice as a per-task attribute Peter Zijlstra
2023-05-31 11:58 ` [RFC][PATCH 13/15] sched/fair: Implement latency-nice Peter Zijlstra
2023-06-06 14:54 ` Vincent Guittot
2023-06-08 10:34 ` Peter Zijlstra
2023-06-08 12:44 ` Peter Zijlstra
2023-10-11 23:24 ` Benjamin Segall
2023-05-31 11:58 ` [RFC][PATCH 14/15] sched/fair: Add sched group latency support Peter Zijlstra
2023-05-31 11:58 ` [RFC][PATCH 15/15] sched/eevdf: Use sched_attr::sched_runtime to set request/slice Peter Zijlstra
2023-06-01 13:55 ` Vincent Guittot
2023-06-08 11:52 ` Peter Zijlstra
2023-08-24 0:52 ` [PATCH 00/15] sched: EEVDF and latency-nice and/or slice-attr Daniel Jordan
2023-09-06 13:13 ` Peter Zijlstra
2023-09-29 16:54 ` Youssef Esmat
2023-10-02 15:55 ` Youssef Esmat
2023-10-02 18:41 ` Peter Zijlstra
2023-10-05 12:05 ` Peter Zijlstra
2023-10-05 14:14 ` Peter Zijlstra
2023-10-05 14:42 ` Peter Zijlstra
2023-10-05 18:23 ` Youssef Esmat
2023-10-06 0:36 ` Youssef Esmat
2023-10-10 8:08 ` Peter Zijlstra
2023-10-07 22:04 ` Peter Zijlstra
2023-10-09 14:41 ` Peter Zijlstra
2023-10-10 0:51 ` Youssef Esmat
2023-10-10 8:01 ` Peter Zijlstra
2023-10-16 16:50 ` Peter Zijlstra
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