March 2021 - Linuxarm - mailweb.openeuler.org

[PATCH v2 for-rc] RDMA/hns: Fix bug during CMDQ initialization
by Weihang Li 22 Mar '21

22 Mar '21

From: Lang Cheng <chenglang(a)huawei.com> When reloading driver, the head/tail pointer of CMDQ may be not at position 0. Then during initialization of CMDQ, if head is reset first, the firmware will start to handle CMDQ because the head is not equal to the tail. The driver can reset tail first since the firmware will be triggerred only by head. This bug is introduced by changing macros of head/tail register without changing the order of initialization. Fixes: 292b3352bd5b ("RDMA/hns: Adjust fields and variables about CMDQ tail/head") Signed-off-by: Lang Cheng <chenglang(a)huawei.com> Signed-off-by: Weihang Li <liweihang(a)huawei.com> --- Changes since v1: - Only retain the bugfix part for -rc branch. - Link: https://patchwork.kernel.org/project/linux-rdma/patch/1615541933-35798-1-gi… drivers/infiniband/hw/hns/hns_roce_hw_v2.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c index c3934ab..ce26f97 100644 --- a/drivers/infiniband/hw/hns/hns_roce_hw_v2.c +++ b/drivers/infiniband/hw/hns/hns_roce_hw_v2.c @@ -1194,8 +1194,10 @@ static void hns_roce_cmq_init_regs(struct hns_roce_dev *hr_dev, bool ring_type) upper_32_bits(dma)); roce_write(hr_dev, ROCEE_TX_CMQ_DEPTH_REG, (u32)ring->desc_num >> HNS_ROCE_CMQ_DESC_NUM_S); - roce_write(hr_dev, ROCEE_TX_CMQ_HEAD_REG, 0); + + /* Make sure to write tail first and then head */ roce_write(hr_dev, ROCEE_TX_CMQ_TAIL_REG, 0); + roce_write(hr_dev, ROCEE_TX_CMQ_HEAD_REG, 0); } else { roce_write(hr_dev, ROCEE_RX_CMQ_BASEADDR_L_REG, (u32)dma); roce_write(hr_dev, ROCEE_RX_CMQ_BASEADDR_H_REG, -- 2.8.1

2 1

[PATCH] spi: imx: Use of_device_get_match_data() helper
by Tian Tao 22 Mar '21

22 Mar '21

Use the of_device_get_match_data() helper instead of open coding. Signed-off-by: Tian Tao <tiantao6(a)hisilicon.com> --- drivers/spi/spi-imx.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index cf55192..4fe767a 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -1548,13 +1548,12 @@ static int spi_imx_slave_abort(struct spi_master *master) static int spi_imx_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; - const struct of_device_id *of_id = - of_match_device(spi_imx_dt_ids, &pdev->dev); struct spi_master *master; struct spi_imx_data *spi_imx; struct resource *res; int ret, irq, spi_drctl; - const struct spi_imx_devtype_data *devtype_data = of_id->data; + const struct spi_imx_devtype_data *devtype_data = + of_device_get_match_data(&pdev->dev); bool slave_mode; u32 val; -- 2.7.4

1 0

[PATCH] i2c: imx: Use devm_request_irq()
by Tian Tao 19 Mar '21

19 Mar '21

Use devm_request_irq() to get rid of manual unregistration. Signed-off-by: Tian Tao <tiantao6(a)hisilicon.com> --- drivers/i2c/busses/i2c-imx.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index b80fdc1..e377d4a 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -1435,8 +1435,8 @@ static int i2c_imx_probe(struct platform_device *pdev) goto rpm_disable; /* Request IRQ */ - ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED, - pdev->name, i2c_imx); + ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, + IRQF_SHARED, pdev->name, i2c_imx); if (ret) { dev_err(&pdev->dev, "can't claim irq %d\n", irq); goto rpm_disable; @@ -1481,7 +1481,6 @@ static int i2c_imx_probe(struct platform_device *pdev) clk_notifier_unregister: clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); - free_irq(irq, i2c_imx); rpm_disable: pm_runtime_put_noidle(&pdev->dev); pm_runtime_disable(&pdev->dev); @@ -1494,7 +1493,7 @@ static int i2c_imx_probe(struct platform_device *pdev) static int i2c_imx_remove(struct platform_device *pdev) { struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev); - int irq, ret; + int ret; ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) @@ -1514,9 +1513,6 @@ static int i2c_imx_remove(struct platform_device *pdev) imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR); clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); - irq = platform_get_irq(pdev, 0); - if (irq >= 0) - free_irq(irq, i2c_imx); clk_disable_unprepare(i2c_imx->clk); pm_runtime_put_noidle(&pdev->dev); -- 2.7.4

2 1

[PATCH] i2c: mlxbf: Remove the unneeded devm_free_irq
by Tian Tao 19 Mar '21

19 Mar '21

Use devm_request_irq to request interrupts,devm_free_irq is not needed to release interrupts. so just remove it. Signed-off-by: Tian Tao <tiantao6(a)hisilicon.com> --- drivers/i2c/busses/i2c-mlxbf.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c index 2fb0532..ea839de 100644 --- a/drivers/i2c/busses/i2c-mlxbf.c +++ b/drivers/i2c/busses/i2c-mlxbf.c @@ -2426,8 +2426,6 @@ static int mlxbf_i2c_remove(struct platform_device *pdev) } mutex_unlock(&mlxbf_i2c_bus_lock); - devm_free_irq(dev, priv->irq, priv); - i2c_del_adapter(&priv->adap); return 0; -- 2.7.4

2 1

[PATCH 0/3] drivers/perf: convert sysfs sprintf/snprintf/scnprintf to sysfs_emit
by Qi Liu 18 Mar '21

18 Mar '21

Use the generic sysfs_emit() and sysfs_emit_at() function to take place of sprintf/snprintf/scnprintf, to avoid buffer overrun. Zihao Tang (1) drivers/perf: convert sysfs snprintf family to sysfs_emit Qi Liu (2): drivers/perf: convert sysfs scnprintf family to sysfs_emit_at drivers/perf: convert sysfs sprintf family to sysfs_emit drivers/perf/arm-cci.c | 12 ++++++------ drivers/perf/arm-ccn.c | 28 ++++++++++++---------------- drivers/perf/arm-cmn.c | 22 +++++++++++----------- drivers/perf/arm_dmc620_pmu.c | 2 +- drivers/perf/arm_dsu_pmu.c | 5 ++--- drivers/perf/arm_smmuv3_pmu.c | 4 ++-- drivers/perf/arm_spe_pmu.c | 3 +-- drivers/perf/fsl_imx8_ddr_perf.c | 7 +++---- drivers/perf/hisilicon/hisi_uncore_pmu.c | 8 ++++---- drivers/perf/qcom_l2_pmu.c | 2 +- drivers/perf/qcom_l3_pmu.c | 4 ++-- drivers/perf/thunderx2_pmu.c | 4 ++-- drivers/perf/xgene_pmu.c | 4 ++-- 13 files changed, 49 insertions(+), 56 deletions(-) -- 2.8.1

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[PATCH v2 0/3] Add support for HiSilicon I2C controller
by Yicong Yang 18 Mar '21

18 Mar '21

Add driver and MAINTAINERS for HiSilicon I2C controller on Kunpeng SoC. Also provide the devm_*() variants for adding the I2C adapters. Change since v1: - fix compile test error on 32bit arch, reported by intel lkp robot: 64 bit division without using kernel wrapper in probe function. Link:https://lore.kernel.org/linux-i2c/1615016946-55670-1-git-send-email-ya… Yicong Yang (3): i2c: core: add managed function for adding i2c adapters i2c: add support for HiSilicon I2C controller MAINTAINERS: Add maintainer for HiSilicon I2C driver MAINTAINERS | 7 + drivers/i2c/busses/Kconfig | 10 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-hisi.c | 525 ++++++++++++++++++++++++++++++++++++++++++ drivers/i2c/i2c-core-base.c | 39 ++++ include/linux/i2c.h | 1 + 6 files changed, 583 insertions(+) create mode 100644 drivers/i2c/busses/i2c-hisi.c -- 2.8.1

2 6

[PATCH v3] iommu: Check dev->iommu in iommu_dev_xxx functions
by Shameer Kolothum 18 Mar '21

18 Mar '21

The device iommu probe/attach might have failed leaving dev->iommu to NULL and device drivers may still invoke these functions resulting in a crash in iommu vendor driver code. Hence make sure we check that. Fixes: a3a195929d40 ("iommu: Add APIs for multiple domains per device") Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi(a)huawei.com> --- v2 --> v3 -Removed iommu_ops from struct dev_iommu. v1 --> v2: -Added iommu_ops to struct dev_iommu based on the discussion with Robin. -Rebased against iommu-tree core branch. --- drivers/iommu/iommu.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index d0b0a15dba84..e10cfa99057c 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -2878,10 +2878,12 @@ EXPORT_SYMBOL_GPL(iommu_fwspec_add_ids); */ int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_enable_feat) - return ops->dev_enable_feat(dev, feat); + if (ops->dev_enable_feat) + return ops->dev_enable_feat(dev, feat); + } return -ENODEV; } @@ -2894,10 +2896,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_enable_feature); */ int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_disable_feat) - return ops->dev_disable_feat(dev, feat); + if (ops->dev_disable_feat) + return ops->dev_disable_feat(dev, feat); + } return -EBUSY; } @@ -2905,10 +2909,12 @@ EXPORT_SYMBOL_GPL(iommu_dev_disable_feature); bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat) { - const struct iommu_ops *ops = dev->bus->iommu_ops; + if (dev->iommu && dev->iommu->iommu_dev) { + const struct iommu_ops *ops = dev->iommu->iommu_dev->ops; - if (ops && ops->dev_feat_enabled) - return ops->dev_feat_enabled(dev, feat); + if (ops->dev_feat_enabled) + return ops->dev_feat_enabled(dev, feat); + } return false; } -- 2.17.1

3 2

[PATCH v2 0/2] EDAC/ghes: Add EDAC device for reporting the CPU cache error count
by Shiju Jose 17 Mar '21

17 Mar '21

CPU cache corrected errors are detected occasionally on few of our ARM64 hardware boards. Though it is rare, the probability of the CPU cache errors frequently occurring can't be avoided. The earlier failure detection by monitoring the cache corrected errors for the frequent occurrences and taking preventive action could prevent more serious hardware faults. On Intel architectures, cache corrected errors are reported and the affected cores are offlined in the architecture specific method. http://www.mcelog.org/cache.html However for the firmware-first error reporting, specifically on ARM64 architecture, there is no provision present for reporting the cache corrected error count to the user-space and taking preventive action such as offline the affected cores. For this purpose, it was suggested to create the CPU EDAC device for the CPU caches for reporting the cache error count for the firmware-first error reporting. User-space application could monitor the recorded corrected error count for the earlier hardware failure detection and could take preventive action, such as offline the corresponding CPU core/s. Changes: RFC V1 -> RFC V2: 1. Fixed feedback by Boris. 1.1. Added reason of this patch. 1.2. Changed CPU errors to CPU cache errors in the drivers/edac/Kconfig 1.3 Changed EDAC cache list to percpu variables. 1.4 Changed configuration depends on ARM64. 1.5. Moved discovery of cacheinfo to ghes_scan_system(). 2. Changes in the descriptions. Shiju Jose (2): EDAC/ghes: Add EDAC device for reporting the CPU cache errors ACPI / APEI: Add reporting ARM64 CPU cache corrected error count Documentation/ABI/testing/sysfs-devices-edac | 15 ++ drivers/acpi/apei/ghes.c | 76 +++++++- drivers/edac/Kconfig | 12 ++ drivers/edac/ghes_edac.c | 186 +++++++++++++++++++ include/acpi/ghes.h | 27 +++ include/linux/cper.h | 4 + 6 files changed, 316 insertions(+), 4 deletions(-) -- 2.17.1

3 5

[PATCH net-next] net: sched: remove unnecessay lock protection for skb_bad_txq/gso_skb
by Yunsheng Lin 17 Mar '21

17 Mar '21

Currently qdisc_lock(q) is taken before enqueuing and dequeuing for lockless qdisc's skb_bad_txq/gso_skb queue, qdisc->seqlock is also taken, which can provide the same protection as qdisc_lock(q). This patch removes the unnecessay qdisc_lock(q) protection for lockless qdisc' skb_bad_txq/gso_skb queue. And dev_reset_queue() takes the qdisc->seqlock for lockless qdisc besides taking the qdisc_lock(q) when doing the qdisc reset, some_qdisc_is_busy() takes both qdisc->seqlock and qdisc_lock(q) when checking qdisc status. It is unnecessary to take both lock while the fast path only take one lock, so this patch also changes it to only take qdisc_lock(q) for locked qdisc, and only take qdisc->seqlock for lockless qdisc. Since qdisc->seqlock is taken for lockless qdisc when calling qdisc_is_running() in some_qdisc_is_busy(), use qdisc->running to decide if the lockless qdisc is running. Signed-off-by: Yunsheng Lin <linyunsheng(a)huawei.com> --- include/net/sch_generic.h | 2 -- net/sched/sch_generic.c | 72 +++++++++++++---------------------------------- 2 files changed, 19 insertions(+), 55 deletions(-) diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 2d6eb60..0e497ed 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -139,8 +139,6 @@ static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc) static inline bool qdisc_is_running(struct Qdisc *qdisc) { - if (qdisc->flags & TCQ_F_NOLOCK) - return spin_is_locked(&qdisc->seqlock); return (raw_read_seqcount(&qdisc->running) & 1) ? true : false; } diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c index 49eae93..a5f1e3c 100644 --- a/net/sched/sch_generic.c +++ b/net/sched/sch_generic.c @@ -38,7 +38,7 @@ EXPORT_SYMBOL(default_qdisc_ops); /* Main transmission queue. */ /* Modifications to data participating in scheduling must be protected with - * qdisc_lock(qdisc) spinlock. + * qdisc_lock(qdisc) or qdisc->seqlock spinlock. * * The idea is the following: * - enqueue, dequeue are serialized via qdisc root lock @@ -51,14 +51,8 @@ EXPORT_SYMBOL(default_qdisc_ops); static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q) { const struct netdev_queue *txq = q->dev_queue; - spinlock_t *lock = NULL; struct sk_buff *skb; - if (q->flags & TCQ_F_NOLOCK) { - lock = qdisc_lock(q); - spin_lock(lock); - } - skb = skb_peek(&q->skb_bad_txq); if (skb) { /* check the reason of requeuing without tx lock first */ @@ -77,9 +71,6 @@ static inline struct sk_buff *__skb_dequeue_bad_txq(struct Qdisc *q) } } - if (lock) - spin_unlock(lock); - return skb; } @@ -96,13 +87,6 @@ static inline struct sk_buff *qdisc_dequeue_skb_bad_txq(struct Qdisc *q) static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q, struct sk_buff *skb) { - spinlock_t *lock = NULL; - - if (q->flags & TCQ_F_NOLOCK) { - lock = qdisc_lock(q); - spin_lock(lock); - } - __skb_queue_tail(&q->skb_bad_txq, skb); if (qdisc_is_percpu_stats(q)) { @@ -112,20 +96,10 @@ static inline void qdisc_enqueue_skb_bad_txq(struct Qdisc *q, qdisc_qstats_backlog_inc(q, skb); q->q.qlen++; } - - if (lock) - spin_unlock(lock); } static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) { - spinlock_t *lock = NULL; - - if (q->flags & TCQ_F_NOLOCK) { - lock = qdisc_lock(q); - spin_lock(lock); - } - while (skb) { struct sk_buff *next = skb->next; @@ -144,8 +118,7 @@ static inline void dev_requeue_skb(struct sk_buff *skb, struct Qdisc *q) skb = next; } - if (lock) - spin_unlock(lock); + __netif_schedule(q); } @@ -207,24 +180,9 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, *packets = 1; if (unlikely(!skb_queue_empty(&q->gso_skb))) { - spinlock_t *lock = NULL; - - if (q->flags & TCQ_F_NOLOCK) { - lock = qdisc_lock(q); - spin_lock(lock); - } skb = skb_peek(&q->gso_skb); - /* skb may be null if another cpu pulls gso_skb off in between - * empty check and lock. - */ - if (!skb) { - if (lock) - spin_unlock(lock); - goto validate; - } - /* skb in gso_skb were already validated */ *validate = false; if (xfrm_offload(skb)) @@ -243,11 +201,10 @@ static struct sk_buff *dequeue_skb(struct Qdisc *q, bool *validate, } else { skb = NULL; } - if (lock) - spin_unlock(lock); + goto trace; } -validate: + *validate = true; if ((q->flags & TCQ_F_ONETXQUEUE) && @@ -1153,13 +1110,15 @@ static void dev_reset_queue(struct net_device *dev, if (nolock) spin_lock_bh(&qdisc->seqlock); - spin_lock_bh(qdisc_lock(qdisc)); + else + spin_lock_bh(qdisc_lock(qdisc)); qdisc_reset(qdisc); - spin_unlock_bh(qdisc_lock(qdisc)); if (nolock) spin_unlock_bh(&qdisc->seqlock); + else + spin_unlock_bh(qdisc_lock(qdisc)); } static bool some_qdisc_is_busy(struct net_device *dev) @@ -1168,20 +1127,27 @@ static bool some_qdisc_is_busy(struct net_device *dev) for (i = 0; i < dev->num_tx_queues; i++) { struct netdev_queue *dev_queue; - spinlock_t *root_lock; struct Qdisc *q; + bool nolock; int val; dev_queue = netdev_get_tx_queue(dev, i); q = dev_queue->qdisc_sleeping; - root_lock = qdisc_lock(q); - spin_lock_bh(root_lock); + nolock = q->flags & TCQ_F_NOLOCK; + + if (nolock) + spin_lock_bh(&q->seqlock); + else + spin_lock_bh(qdisc_lock(q)); val = (qdisc_is_running(q) || test_bit(__QDISC_STATE_SCHED, &q->state)); - spin_unlock_bh(root_lock); + if (nolock) + spin_unlock_bh(&q->seqlock); + else + spin_unlock_bh(qdisc_lock(q)); if (val) return true; -- 2.7.4

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[RFC PATCH v4 0/3] scheduler: expose the topology of clusters and add cluster scheduler
by Barry Song 16 Mar '21

16 Mar '21

ARM64 server chip Kunpeng 920 has 6 or 8 clusters in each NUMA node, and each cluster has 4 cpus. All clusters share L3 cache data while each cluster has local L3 tag. On the other hand, each cluster will share some internal system bus. This means cache is much more affine inside one cluster than across clusters. +-----------------------------------+ +---------+ | +------+ +------+ +---------------------------+ | | | CPU0 | | cpu1 | | +-----------+ | | | +------+ +------+ | | | | | | +----+ L3 | | | | +------+ +------+ cluster | | tag | | | | | CPU2 | | CPU3 | | | | | | | +------+ +------+ | +-----------+ | | | | | | +-----------------------------------+ | | +-----------------------------------+ | | | +------+ +------+ +--------------------------+ | | | | | | | +-----------+ | | | +------+ +------+ | | | | | | | | L3 | | | | +------+ +------+ +----+ tag | | | | | | | | | | | | | | +------+ +------+ | +-----------+ | | | | | | +-----------------------------------+ | L3 | | data | +-----------------------------------+ | | | +------+ +------+ | +-----------+ | | | | | | | | | | | | | +------+ +------+ +----+ L3 | | | | | | tag | | | | +------+ +------+ | | | | | | | | | | ++ +-----------+ | | | +------+ +------+ |---------------------------+ | +-----------------------------------| | | +-----------------------------------| | | | +------+ +------+ +---------------------------+ | | | | | | | +-----------+ | | | +------+ +------+ | | | | | | +----+ L3 | | | | +------+ +------+ | | tag | | | | | | | | | | | | | | +------+ +------+ | +-----------+ | | | | | | +-----------------------------------+ | | +-----------------------------------+ | | | +------+ +------+ +--------------------------+ | | | | | | | +-----------+ | | | +------+ +------+ | | | | | There is a similar need for clustering in x86. Some x86 cores could share L2 caches that is similar to the cluster in Kupeng 920 (e.g. on Jacobsville there are 6 clusters of 4 Atom cores, each cluster sharing a separate L2, and 24 cores sharing L3). Having a sched_domain for clusters will bring two aspects of improvement: 1. spreading unrelated tasks among clusters, which decreases the contention of resources and improve the throughput. unrelated tasks might be put randomly without cluster sched_domain: +-------------------+ +-----------------+ | +----+ +----+ | | | | |task| |task| | | | | |1 | |2 | | | | | +----+ +----+ | | | | | | | | cluster1 | | cluster2 | +-------------------+ +-----------------+ but with cluster sched_domain, they are likely to spread due to LB: +-------------------+ +-----------------+ | +----+ | | +----+ | | |task| | | |task| | | |1 | | | |2 | | | +----+ | | +----+ | | | | | | cluster1 | | cluster2 | +-------------------+ +-----------------+ 2. gathering related tasks within a cluster, which improves the cache affinity of tasks talking with each other. Without cluster sched_domain, related tasks might be put randomly. In case task1-8 have relationship as below: Task1 wakes up task4 Task2 wakes up task5 Task3 wakes up task6 Task4 wakes up task7 With the tuning of select_idle_cpu() to scan local cluster first, those tasks might get a chance to be gathered like: +---------------------------+ +----------------------+ | +----+ +-----+ | | +----+ +-----+ | | |task| |task | | | |task| |task | | | |1 | | 4 | | | |2 | |5 | | | +----+ +-----+ | | +----+ +-----+ | | | | | | cluster1 | | cluster2 | | | | | | | | | | +-----+ +------+ | | +-----+ +------+ | | |task | | task | | | |task | |task | | | |3 | | 6 | | | |4 | |8 | | | +-----+ +------+ | | +-----+ +------+ | +---------------------------+ +----------------------+ Otherwise, the result might be: +---------------------------+ +----------------------+ | +----+ +-----+ | | +----+ +-----+ | | |task| |task | | | |task| |task | | | |1 | | 2 | | | |5 | |6 | | | +----+ +-----+ | | +----+ +-----+ | | | | | | cluster1 | | cluster2 | | | | | | | | | | +-----+ +------+ | | +-----+ +------+ | | |task | | task | | | |task | |task | | | |3 | | 4 | | | |7 | |8 | | | +-----+ +------+ | | +-----+ +------+ | +---------------------------+ +----------------------+ -v4: * rebased to tip/sched/core with the latest unified code of select_idle_cpu * added Tim's patch for x86 Jacobsville * also added benchmark data of spreading unrelated tasks * avoided the iteration of sched_domain by moving to static_key(addressing Vincent's comment * used acpi_cpu_id for acpi_find_processor_node(addressing Masa's comment) Barry Song (1): scheduler: add scheduler level for clusters Jonathan Cameron (1): topology: Represent clusters of CPUs within a die. Tim Chen (1): scheduler: Add cluster scheduler level for x86 Documentation/admin-guide/cputopology.rst | 26 ++++++++++-- arch/arm64/Kconfig | 7 ++++ arch/arm64/kernel/topology.c | 2 + arch/x86/Kconfig | 8 ++++ arch/x86/include/asm/smp.h | 7 ++++ arch/x86/include/asm/topology.h | 1 + arch/x86/kernel/cpu/cacheinfo.c | 1 + arch/x86/kernel/cpu/common.c | 3 ++ arch/x86/kernel/smpboot.c | 43 +++++++++++++++++++- drivers/acpi/pptt.c | 63 +++++++++++++++++++++++++++++ drivers/base/arch_topology.c | 14 +++++++ drivers/base/topology.c | 10 +++++ include/linux/acpi.h | 5 +++ include/linux/arch_topology.h | 5 +++ include/linux/sched/cluster.h | 19 +++++++++ include/linux/sched/sd_flags.h | 9 +++++ include/linux/sched/topology.h | 7 ++++ include/linux/topology.h | 13 ++++++ kernel/sched/core.c | 18 +++++++++ kernel/sched/fair.c | 66 ++++++++++++++++++++++++------- kernel/sched/sched.h | 1 + kernel/sched/topology.c | 6 +++ 22 files changed, 315 insertions(+), 19 deletions(-) create mode 100644 include/linux/sched/cluster.h -- 1.8.3.1

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