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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Scott Wood <swood@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.4 03/50] sched/core: Don't skip remote tick for idle CPUs
Date: Sat, 22 Feb 2020 21:21:48 -0500	[thread overview]
Message-ID: <20200223022235.1404-3-sashal@kernel.org> (raw)
In-Reply-To: <20200223022235.1404-1-sashal@kernel.org>

From: Scott Wood <swood@redhat.com>

[ Upstream commit 488603b815a7514c7009e6fc339d74ed4a30f343 ]

This will be used in the next patch to get a loadavg update from
nohz cpus.  The delta check is skipped because idle_sched_class
doesn't update se.exec_start.

Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/1578736419-14628-2-git-send-email-swood@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/sched/core.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index dfaefb175ba05..5cbf64db4e0a3 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3667,22 +3667,24 @@ static void sched_tick_remote(struct work_struct *work)
 	 * statistics and checks timeslices in a time-independent way, regardless
 	 * of when exactly it is running.
 	 */
-	if (idle_cpu(cpu) || !tick_nohz_tick_stopped_cpu(cpu))
+	if (!tick_nohz_tick_stopped_cpu(cpu))
 		goto out_requeue;
 
 	rq_lock_irq(rq, &rf);
 	curr = rq->curr;
-	if (is_idle_task(curr) || cpu_is_offline(cpu))
+	if (cpu_is_offline(cpu))
 		goto out_unlock;
 
 	update_rq_clock(rq);
-	delta = rq_clock_task(rq) - curr->se.exec_start;
 
-	/*
-	 * Make sure the next tick runs within a reasonable
-	 * amount of time.
-	 */
-	WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
+	if (!is_idle_task(curr)) {
+		/*
+		 * Make sure the next tick runs within a reasonable
+		 * amount of time.
+		 */
+		delta = rq_clock_task(rq) - curr->se.exec_start;
+		WARN_ON_ONCE(delta > (u64)NSEC_PER_SEC * 3);
+	}
 	curr->sched_class->task_tick(rq, curr, 0);
 
 out_unlock:
-- 
2.20.1


  parent reply	other threads:[~2020-02-23  2:34 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-23  2:21 [PATCH AUTOSEL 5.4 01/50] ipmi:ssif: Handle a possible NULL pointer reference Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 02/50] drm/msm: Set dma maximum segment size for mdss Sasha Levin
2020-02-23  2:21 ` Sasha Levin [this message]
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 04/50] timers/nohz: Update NOHZ load in remote tick Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 05/50] sched/fair: Prevent unlimited runtime on throttled group Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 06/50] dax: pass NOWAIT flag to iomap_apply Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 07/50] mac80211: consider more elements in parsing CRC Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 08/50] cfg80211: check wiphy driver existence for drvinfo report Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 09/50] s390/zcrypt: fix card and queue total counter wrap Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 10/50] qmi_wwan: re-add DW5821e pre-production variant Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 11/50] qmi_wwan: unconditionally reject 2 ep interfaces Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 12/50] NFSv4: Fix races between open and dentry revalidation Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 13/50] perf/smmuv3: Use platform_get_irq_optional() for wired interrupt Sasha Levin
2020-02-23  2:21 ` [PATCH AUTOSEL 5.4 14/50] arm/ftrace: Fix BE text poking Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 15/50] sched/psi: Fix OOB write when writing 0 bytes to PSI files Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 16/50] perf/x86/intel: Add Elkhart Lake support Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 17/50] perf/x86/cstate: Add Tremont support Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 18/50] perf/x86/msr: " Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 19/50] ceph: do not execute direct write in parallel if O_APPEND is specified Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 20/50] ARM: dts: sti: fixup sound frame-inversion for stihxxx-b2120.dtsi Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 21/50] drm/amd/display: Do not set optimized_require to false after plane disable Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 22/50] RDMA/siw: Remove unwanted WARN_ON in siw_cm_llp_data_ready() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 23/50] drm/amd/display: Check engine is not NULL before acquiring Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 24/50] drm/amd/display: Limit minimum DPPCLK to 100MHz Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 25/50] drm/amd/display: Add initialitions for PLL2 clock source Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 26/50] amdgpu: Prevent build errors regarding soft/hard-float FP ABI tags Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 27/50] soc/tegra: fuse: Fix build with Tegra194 configuration Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 28/50] i40e: Fix the conditional for i40e_vc_validate_vqs_bitmaps Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 29/50] net: ena: fix potential crash when rxfh key is NULL Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 30/50] net: ena: fix uses of round_jiffies() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 31/50] net: ena: add missing ethtool TX timestamping indication Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 32/50] net: ena: fix incorrect default RSS key Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 33/50] net: ena: rss: do not allocate key when not supported Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 34/50] net: ena: rss: fix failure to get indirection table Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 35/50] net: ena: rss: store hash function as values and not bits Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 36/50] net: ena: fix incorrectly saving queue numbers when setting RSS indirection table Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 37/50] net: ena: fix corruption of dev_idx_to_host_tbl Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 38/50] net: ena: ethtool: use correct value for crc32 hash Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 39/50] net: ena: ena-com.c: prevent NULL pointer dereference Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 40/50] enic: prevent waking up stopped tx queues over watchdog reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 41/50] ice: update Unit Load Status bitmask to check after reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 42/50] cifs: Fix mode output in debugging statements Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 43/50] bcache: ignore pending signals when creating gc and allocator thread Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 44/50] cfg80211: add missing policy for NL80211_ATTR_STATUS_CODE Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 45/50] mac80211: fix wrong 160/80+80 MHz setting Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 46/50] net: hns3: add management table after IMP reset Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 47/50] net: hns3: fix a copying IPv6 address error in hclge_fd_get_flow_tuples() Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 48/50] nvme/tcp: fix bug on double requeue when send fails Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 49/50] nvme: prevent warning triggered by nvme_stop_keep_alive Sasha Levin
2020-02-23  2:22 ` [PATCH AUTOSEL 5.4 50/50] nvme/pci: move cqe check after device shutdown Sasha Levin

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