- Dec 07, 2023
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Ming Lei authored
group_cpus_evenly() could be part of storage driver's error handler, such as nvme driver, when may happen during CPU hotplug, in which storage queue has to drain its pending IOs because all CPUs associated with the queue are offline and the queue is becoming inactive. And handling IO needs error handler to provide forward progress. Then deadlock is caused: 1) inside CPU hotplug handler, CPU hotplug lock is held, and blk-mq's handler is waiting for inflight IO 2) error handler is waiting for CPU hotplug lock 3) inflight IO can't be completed in blk-mq's CPU hotplug handler because error handling can't provide forward progress. Solve the deadlock by not holding CPU hotplug lock in group_cpus_evenly(), in which two stage spreads are taken: 1) the 1st stage is over all present CPUs; 2) the end stage is over all other CPUs. Turns out the two stage spread just needs consistent 'cpu_present_mask', and remove the CPU hotplug lock by storing it into one local cache. This way doesn't change correctness, because all CPUs are still covered. Link: https://lkml.kernel.org/r/20231120083559.285174-1-ming.lei@redhat.com Signed-off-by:
Ming Lei <ming.lei@redhat.com> Reported-by:
Yi Zhang <yi.zhang@redhat.com> Reported-by:
Guangwu Zhang <guazhang@redhat.com> Tested-by:
Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by:
Jens Axboe <axboe@kernel.dk> Cc: Keith Busch <kbusch@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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- Apr 21, 2023
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Xie Yongji authored
Export group_cpus_evenly() so that some modules can make use of it to group CPUs evenly according to NUMA and CPU locality. Signed-off-by:
Xie Yongji <xieyongji@bytedance.com> Acked-by:
Jason Wang <jasowang@redhat.com> Message-Id: <20230323053043.35-2-xieyongji@bytedance.com> Signed-off-by:
Michael S. Tsirkin <mst@redhat.com>
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- Jan 18, 2023
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Ingo Molnar authored
allnoconfig grew these new build warnings in lib/group_cpus.c: lib/group_cpus.c:247:12: warning: ‘__group_cpus_evenly’ defined but not used [-Wunused-function] lib/group_cpus.c:75:13: warning: ‘build_node_to_cpumask’ defined but not used [-Wunused-function] lib/group_cpus.c:66:13: warning: ‘free_node_to_cpumask’ defined but not used [-Wunused-function] lib/group_cpus.c:43:23: warning: ‘alloc_node_to_cpumask’ defined but not used [-Wunused-function] Widen the #ifdef CONFIG_SMP block to not expose unused helpers on non-SMP builds. Also annotate the preprocessor branches for better readability. Fixes: f7b3ea8c ("genirq/affinity: Move group_cpus_evenly() into lib/") Cc: Ming Lei <ming.lei@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20221227022905.352674-6-ming.lei@redhat.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- Jan 17, 2023
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Ming Lei authored
group_cpus_evenly() has become a generic function which can be used for other subsystems than the interrupt subsystem, so move it into lib/. Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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Ming Lei authored
Map irq vector into group, which allows to abstract the algorithm for a generic use case outside of the interrupt core. Rename irq_build_affinity_masks as group_cpus_evenly, so the API can be reused for blk-mq to make default queue mapping even though irq vectors aren't involved. No functional change, just rename vector as group. Signed-off-by:
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Ming Lei authored
Prepare for abstracting irq_build_affinity_masks() into a public function for assigning all CPUs evenly into several groups. Don't pass irq_affinity_desc array to irq_build_affinity_masks, instead return a cpumask array by storing each assigned group into one element of the array. This allows to provide a generic interface for grouping all CPUs evenly from a NUMA and CPU locality viewpoint, and the cost is one extra allocation in irq_build_affinity_masks(), which should be fine since it is done via GFP_KERNEL and irq_build_affinity_masks() is a slow path anyway. Signed-off-by:
John Garry <john.g.garry@oracle.com> Reviewed-by:
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Ming Lei authored
Pass affinity managed mask array to irq_build_affinity_masks() so that the index of the first affinity managed vector is always zero. This allows to simplify the implementation a bit. Signed-off-by:
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Ming Lei authored
The 'firstvec' parameter is always same with the parameter of 'startvec', so use 'startvec' directly inside irq_build_affinity_masks(). Signed-off-by:
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- Jun 03, 2022
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Yury Norov authored
__irq_build_affinity_masks() calls cpumask_weight() to check if any bit of a given cpumask is set. We can do it more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by:Yury Norov <yury.norov@gmail.com>
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- Apr 11, 2022
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Rei Yamamoto authored
If CPUs on a node are offline at boot time, the number of nodes is different when building affinity masks for present cpus and when building affinity masks for possible cpus. This causes the following problem: In the case that the number of vectors is less than the number of nodes there are cases where bits of masks for present cpus are overwritten when building masks for possible cpus. Fix this by excluding CPUs, which are not part of the current build mask (present/possible). [ tglx: Massaged changelog and added comment ] Fixes: b8259219 ("genirq/affinity: Spread IRQs to all available NUMA nodes") Signed-off-by:
Rei Yamamoto <yamamoto.rei@jp.fujitsu.com> Signed-off-by:
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- Apr 10, 2022
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Yury Norov authored
__irq_build_affinity_masks() calls cpumask_weight() to check if any bit of a given cpumask is set. This can be done more efficiently with cpumask_empty() because cpumask_empty() stops traversing the cpumask as soon as it finds first set bit, while cpumask_weight() counts all bits unconditionally. Signed-off-by:
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- Aug 10, 2021
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Sebastian Andrzej Siewior authored
The functions get_online_cpus() and put_online_cpus() have been deprecated during the CPU hotplug rework. They map directly to cpus_read_lock() and cpus_read_unlock(). Replace deprecated CPU-hotplug functions with the official version. The behavior remains unchanged. Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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- Aug 28, 2019
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Ming Lei authored
When CONFIG_CPUMASK_OFFSTACK isn't enabled, 'cpumask_var_t' is as 'typedef struct cpumask cpumask_var_t[1]', so the argument 'node_to_cpumask' alloc_nodes_vectors() can't be declared as 'const cpumask_var_t *' Fixes the following warning: kernel/irq/affinity.c: In function '__irq_build_affinity_masks': alloc_nodes_vectors(numvecs, node_to_cpumask, cpu_mask, ^ kernel/irq/affinity.c:128:13: note: expected 'const struct cpumask (*)[1]' but argument is of type 'struct cpumask (*)[1]' static void alloc_nodes_vectors(unsigned int numvecs, ^ Fixes: b1a5a73e ("genirq/affinity: Spread vectors on node according to nr_cpu ratio") Reported-by:kbuild test robot <lkp@intel.com> Signed-off-by:
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- Aug 27, 2019
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Ming Lei authored
Now __irq_build_affinity_masks() spreads vectors evenly per node, but there is a case that not all vectors have been spread when each numa node has a different number of CPUs which triggers the warning in the spreading code. Improve the spreading algorithm by - assigning vectors according to the ratio of the number of CPUs on a node to the number of remaining CPUs. - running the assignment from smaller nodes to bigger nodes to guarantee that every active node gets allocated at least one vector. This ensures that all vectors are spread out. Asided of that the spread becomes more fair if the nodes have different number of CPUs. For example, on the following machine: CPU(s): 16 On-line CPU(s) list: 0-15 Thread(s) per core: 1 Core(s) per socket: 8 Socket(s): 2 NUMA node(s): 2 ... NUMA node0 CPU(s): 0,1,3,5-9,11,13-15 NUMA node1 CPU(s): 2,4,10,12 When a driver requests to allocate 8 vectors, the following spread results: irq 31, cpu list 2,4 irq 32, cpu list 10,12 irq 33, cpu list 0-1 irq 34, cpu list 3,5 irq 35, cpu list 6-7 irq 36, cpu list 8-9 irq 37, cpu list 11,13 irq 38, cpu list 14-15 So Node 0 has now 6 and Node 1 has 2 vectors assigned. The original algorithm assigned 4 vectors on each node which was unfair versus Node 0. [ tglx: Massaged changelog ] Reported-by:
Jon Derrick <jonathan.derrick@intel.com> Signed-off-by:
Keith Busch <kbusch@kernel.org> Reviewed-by:
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Ming Lei authored
One invariant of __irq_build_affinity_masks() is that all CPUs in the specified masks (cpu_mask AND node_to_cpumask for each node) should be covered during the spread. Even though all requested vectors have been reached, it's still required to spread vectors among remained CPUs. A similar policy has been taken in case of 'numvecs <= nodes' already. So remove the following check inside the loop: if (done >= numvecs) break; Meantime assign at least 1 vector for remaining nodes if 'numvecs' vectors have been handled already. Also, if the specified cpumask for one numa node is empty, simply do not spread vectors on this node. Signed-off-by:
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- Aug 08, 2019
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Ming Lei authored
Since commit c66d4bd1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets"), irq_create_affinity_masks() returns NULL in case of single vector. This change has caused regression on some drivers, such as lpfc. The problem is that single vector requests can happen in some generic cases: 1) kdump kernel 2) irq vectors resource is close to exhaustion. If in that situation the affinity mask for a single vector is not created, every caller has to handle the special case. There is no reason why the mask cannot be created, so remove the check for a single vector and create the mask. Fixes: c66d4bd1 ("genirq/affinity: Add new callback for (re)calculating interrupt sets") Signed-off-by:
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- Jun 12, 2019
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Minwoo Im authored
The *affd argument is neither used in irq_build_affinity_masks() nor __irq_build_affinity_masks(). Remove it. Signed-off-by:
Minwoo Im <minwoo.im.dev@gmail.com> Signed-off-by:
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- Feb 18, 2019
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Thomas Gleixner authored
Now that the NVME driver is converted over to the calc_set() callback, the workarounds of the original set support can be removed. Signed-off-by:
Marc Zyngier <marc.zyngier@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bjorn Helgaas <helgaas@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Cc: Keith Busch <keith.busch@intel.com> Cc: Sumit Saxena <sumit.saxena@broadcom.com> Cc: Kashyap Desai <kashyap.desai@broadcom.com> Cc: Shivasharan Srikanteshwara <shivasharan.srikanteshwara@broadcom.com> Link: https://lkml.kernel.org/r/20190216172228.689834224@linutronix.de
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Ming Lei authored
The interrupt affinity spreading mechanism supports to spread out affinities for one or more interrupt sets. A interrupt set contains one or more interrupts. Each set is mapped to a specific functionality of a device, e.g. general I/O queues and read I/O queus of multiqueue block devices. The number of interrupts per set is defined by the driver. It depends on the total number of available interrupts for the device, which is determined by the PCI capabilites and the availability of underlying CPU resources, and the number of queues which the device provides and the driver wants to instantiate. The driver passes initial configuration for the interrupt allocation via a pointer to struct irq_affinity. Right now the allocation mechanism is complex as it requires to have a loop in the driver to determine the maximum number of interrupts which are provided by the PCI capabilities and the underlying CPU resources. This loop would have to be replicated in every driver which wants to utilize this mechanism. That's unwanted code duplication and error prone. In order to move this into generic facilities it is required to have a mechanism, which allows the recalculation of the interrupt sets and their size, in the core code. As the core code does not have any knowledge about the underlying device, a driver specific callback is required in struct irq_affinity, which can be invoked by the core code. The callback gets the number of available interupts as an argument, so the driver can calculate the corresponding number and size of interrupt sets. At the moment the struct irq_affinity pointer which is handed in from the driver and passed through to several core functions is marked 'const', but for the callback to be able to modify the data in the struct it's required to remove the 'const' qualifier. Add the optional callback to struct irq_affinity, which allows drivers to recalculate the number and size of interrupt sets and remove the 'const' qualifier. For simple invocations, which do not supply a callback, a default callback is installed, which just sets nr_sets to 1 and transfers the number of spreadable vectors to the set_size array at index 0. This is for now guarded by a check for nr_sets != 0 to keep the NVME driver working until it is converted to the callback mechanism. To make sure that the driver configuration is correct under all circumstances the callback is invoked even when there are no interrupts for queues left, i.e. the pre/post requirements already exhaust the numner of available interrupts. At the PCI layer irq_create_affinity_masks() has to be invoked even for the case where the legacy interrupt is used. That ensures that the callback is invoked and the device driver can adjust to that situation. [ tglx: Fixed the simple case (no sets required). Moved the sanity check for nr_sets after the invocation of the callback so it catches broken drivers. Fixed the kernel doc comments for struct irq_affinity and de-'This patch'-ed the changelog ] Signed-off-by:
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Ming Lei authored
The interrupt affinity spreading mechanism supports to spread out affinities for one or more interrupt sets. A interrupt set contains one or more interrupts. Each set is mapped to a specific functionality of a device, e.g. general I/O queues and read I/O queus of multiqueue block devices. The number of interrupts per set is defined by the driver. It depends on the total number of available interrupts for the device, which is determined by the PCI capabilites and the availability of underlying CPU resources, and the number of queues which the device provides and the driver wants to instantiate. The driver passes initial configuration for the interrupt allocation via a pointer to struct irq_affinity. Right now the allocation mechanism is complex as it requires to have a loop in the driver to determine the maximum number of interrupts which are provided by the PCI capabilities and the underlying CPU resources. This loop would have to be replicated in every driver which wants to utilize this mechanism. That's unwanted code duplication and error prone. In order to move this into generic facilities it is required to have a mechanism, which allows the recalculation of the interrupt sets and their size, in the core code. As the core code does not have any knowledge about the underlying device, a driver specific callback will be added to struct affinity_desc, which will be invoked by the core code. The callback will get the number of available interupts as an argument, so the driver can calculate the corresponding number and size of interrupt sets. To support this, two modifications for the handling of struct irq_affinity are required: 1) The (optional) interrupt sets size information is contained in a separate array of integers and struct irq_affinity contains a pointer to it. This is cumbersome and as the maximum number of interrupt sets is small, there is no reason to have separate storage. Moving the size array into struct affinity_desc avoids indirections and makes the code simpler. 2) At the moment the struct irq_affinity pointer which is handed in from the driver and passed through to several core functions is marked 'const'. With the upcoming callback to recalculate the number and size of interrupt sets, it's necessary to remove the 'const' qualifier. Otherwise the callback would not be able to update the data. Implement #1 and store the interrupt sets size in 'struct irq_affinity'. No functional change. [ tglx: Fixed the memcpy() size so it won't copy beyond the size of the source. Fixed the kernel doc comments for struct irq_affinity and de-'This patch'-ed the changelog ] Signed-off-by:
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Thomas Gleixner authored
All information and calculations in the interrupt affinity spreading code is strictly unsigned int. Though the code uses int all over the place. Convert it over to unsigned int. Signed-off-by:
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- Feb 10, 2019
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Ming Lei authored
'node_to_cpumask' is just one temparay variable for irq_build_affinity_masks(), so move it into irq_build_affinity_masks(). No functioanl change. Signed-off-by:
Bjorn Helgaas <bhelgaas@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: Sagi Grimberg <sagi@grimberg.me> Cc: linux-nvme@lists.infradead.org Cc: linux-pci@vger.kernel.org Link: https://lkml.kernel.org/r/20190125095347.17950-2-ming.lei@redhat.com
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- Dec 19, 2018
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Dou Liyang authored
Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. That limitation was reported by Kashyap and Sumit. Expand struct irq_affinity_desc with a new bit 'is_managed' which is set for truly managed interrupts (queue interrupts) and cleared for the general device interrupts. [ tglx: Simplify code and massage changelog ] Reported-by:
Kashyap Desai <kashyap.desai@broadcom.com> Reported-by:
Sumit Saxena <sumit.saxena@broadcom.com> Signed-off-by:
Dou Liyang <douliyangs@gmail.com> Signed-off-by:
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Dou Liyang authored
The interrupt affinity management uses straight cpumask pointers to convey the automatically assigned affinity masks for managed interrupts. The core interrupt descriptor allocation also decides based on the pointer being non NULL whether an interrupt is managed or not. Devices which use managed interrupts usually have two classes of interrupts: - Interrupts for multiple device queues - Interrupts for general device management Currently both classes are treated the same way, i.e. as managed interrupts. The general interrupts get the default affinity mask assigned while the device queue interrupts are spread out over the possible CPUs. Treating the general interrupts as managed is both a limitation and under certain circumstances a bug. Assume the following situation: default_irq_affinity = 4..7 So if CPUs 4-7 are offlined, then the core code will shut down the device management interrupts because the last CPU in their affinity mask went offline. It's also a limitation because it's desired to allow manual placement of the general device interrupts for various reasons. If they are marked managed then the interrupt affinity setting from both user and kernel space is disabled. To remedy that situation it's required to convey more information than the cpumasks through various interfaces related to interrupt descriptor allocation. Instead of adding yet another argument, create a new data structure 'irq_affinity_desc' which for now just contains the cpumask. This struct can be expanded to convey auxilliary information in the next step. No functional change, just preparatory work. [ tglx: Simplified logic and clarified changelog ] Suggested-by:
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Thomas Gleixner authored
Plus other coding style issues which stood out while staring at that code. Signed-off-by:
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- Nov 05, 2018
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Jens Axboe authored
A driver may have a need to allocate multiple sets of MSI/MSI-X interrupts, and have them appropriately affinitized. Add support for defining a number of sets in the irq_affinity structure, of varying sizes, and get each set affinitized correctly across the machine. [ tglx: Minor changelog tweaks ] Signed-off-by:
Hannes Reinecke <hare@suse.com> Reviewed-by:
Keith Busch <keith.busch@intel.com> Reviewed-by:
Sagi Grimberg <sagi@grimberg.me> Cc: linux-block@vger.kernel.org Link: https://lkml.kernel.org/r/20181102145951.31979-5-ming.lei@redhat.com
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Ming Lei authored
No functional change. Prepares for support of allocating and affinitizing sets of interrupts, in which each set of interrupts needs a full two stage spreading. The first vector argument is necessary for this so the affinitizing starts from the first vector of each set. [ tglx: Minor changelog tweaks ] Signed-off-by:
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Ming Lei authored
No functional change. Prepares for supporting allocating and affinitizing interrupt sets. [ tglx: Minor changelog tweaks ] Signed-off-by:
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Long Li authored
If the number of NUMA nodes exceeds the number of MSI/MSI-X interrupts which are allocated for a device, the interrupt affinity spreading code fails to spread them across all nodes. The reason is, that the spreading code starts from node 0 and continues up to the number of interrupts requested for allocation. This leaves the nodes past the last interrupt unused. This results in interrupt concentration on the first nodes which violates the assumption of the block layer that all nodes are covered evenly. As a consequence the NUMA nodes above the number of interrupts are all assigned to hardware queue 0 and therefore NUMA node 0, which results in bad performance and has CPU hotplug implications, because queue 0 gets shut down when the last CPU of node 0 is offlined. Go over all NUMA nodes and assign them round-robin to all requested interrupts to solve this. [ tglx: Massaged changelog ] Signed-off-by:
Long Li <longli@microsoft.com> Signed-off-by:
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- Apr 06, 2018
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Ming Lei authored
Commit 84676c1f ("genirq/affinity: assign vectors to all possible CPUs") tried to spread the interrupts accross all possible CPUs to make sure that in case of phsyical hotplug (e.g. virtualization) the CPUs which get plugged in after the device was initialized are targeted by a hardware queue and the corresponding interrupt. This has a downside in cases where the ACPI tables claim that there are more possible CPUs than present CPUs and the number of interrupts to spread out is smaller than the number of possible CPUs. These bogus ACPI tables are unfortunately not uncommon. In such a case the vector spreading algorithm assigns interrupts to CPUs which can never be utilized and as a consequence these interrupts are unused instead of being mapped to present CPUs. As a result the performance of the device is suboptimal. To fix this spread the interrupt vectors in two stages: 1) Spread as many interrupts as possible among the present CPUs 2) Spread the remaining vectors among non present CPUs On a 8 core system, where CPU 0-3 are present and CPU 4-7 are not present, for a device with 4 queues the resulting interrupt affinity is: 1) Before 84676c1f ("genirq/affinity: assign vectors to all possible CPUs") irq 39, cpu list 0 irq 40, cpu list 1 irq 41, cpu list 2 irq 42, cpu list 3 2) With 84676c1f ("genirq/affinity: assign vectors to all possible CPUs") irq 39, cpu list 0-2 irq 40, cpu list 3-4,6 irq 41, cpu list 5 irq 42, cpu list 7 3) With the refined vector spread applied: irq 39, cpu list 0,4 irq 40, cpu list 1,6 irq 41, cpu list 2,5 irq 42, cpu list 3,7 On a 8 core system, where all CPUs are present the resulting interrupt affinity for the 4 queues is: irq 39, cpu list 0,1 irq 40, cpu list 2,3 irq 41, cpu list 4,5 irq 42, cpu list 6,7 This is independent of the number of CPUs which are online at the point of initialization because in such a system the offline CPUs can be easily onlined afterwards, while in non-present CPUs need to be plugged physically or virtually which requires external interaction. The downside of this approach is that in case of physical hotplug the interrupt vector spreading might be suboptimal when CPUs 4-7 are physically plugged. Suboptimal from a NUMA point of view and due to the single target nature of interrupt affinities the later plugged CPUs might not be targeted by interrupts at all. Though, physical hotplug systems are not the common case while the broken ACPI table disease is wide spread. So it's preferred to have as many interrupts as possible utilized at the point where the device is initialized. Block multi-queue devices like NVME create a hardware queue per possible CPU, so the goal of commit 84676c1f to assign one interrupt vector per possible CPU is still achieved even with physical/virtual hotplug. [ tglx: Changed from online to present CPUs for the first spreading stage, renamed variables for readability sake, added comments and massaged changelog ] Reported-by:
Laurence Oberman <loberman@redhat.com> Signed-off-by:
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Ming Lei authored
To support two stage irq vector spreading, it's required to add a starting point to the spreading function. No functional change, just preparatory work for the actual two stage change. [ tglx: Renamed variables, tidied up the code and massaged changelog ] Signed-off-by:
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Ming Lei authored
No functional change, just prepare for converting to 2-stage irq vector spreading. Signed-off-by:
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Ming Lei authored
The following patches will introduce two stage irq spreading for improving irq spread on all possible CPUs. No functional change. Signed-off-by:
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Thomas Gleixner authored
When the allocation of node_to_possible_cpumask fails, then irq_create_affinity_masks() returns with a pointer to the empty affinity masks array, which will cause malfunction. Reorder the allocations so the masks array allocation comes last and every failure path returns NULL. Fixes: 9a0ef98e ("genirq/affinity: Assign vectors to all present CPUs") Signed-off-by:
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- Jan 12, 2018
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Christoph Hellwig authored
Currently we assign managed interrupt vectors to all present CPUs. This works fine for systems were we only online/offline CPUs. But in case of systems that support physical CPU hotplug (or the virtualized version of it) this means the additional CPUs covered for in the ACPI tables or on the command line are not catered for. To fix this we'd either need to introduce new hotplug CPU states just for this case, or we can start assining vectors to possible but not present CPUs. Reported-by:
Christian Borntraeger <borntraeger@de.ibm.com> Tested-by:
Stefan Haberland <sth@linux.vnet.ibm.com> Fixes: 4b855ad3 ("blk-mq: Create hctx for each present CPU") Cc: linux-kernel@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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- Nov 02, 2017
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Greg Kroah-Hartman authored
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by:
Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by:
Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- Jun 22, 2017
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Christoph Hellwig authored
Currently the irq vector spread algorithm is restricted to online CPUs, which ties the IRQ mapping to the currently online devices and doesn't deal nicely with the fact that CPUs could come and go rapidly due to e.g. power management. Instead assign vectors to all present CPUs to avoid this churn. Build a map of all possible CPUs for a given node, as the architectures only provide a map of all onlines CPUs. Do this dynamically on each call for the vector assingments, which is a bit suboptimal and could be optimized in the future by provinding a mapping from the arch code. Signed-off-by:
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- May 22, 2017
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Michael Hernandez authored
min_vecs is the minimum amount of vectors needed to operate in MSI-X mode which may just include the vectors that don't need affinity. Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks on each vector. Fixes: dfef358b ("PCI/MSI: Don't apply affinity if there aren't enough vectors left") Signed-off-by:
Michael Hernandez <michael.hernandez@cavium.com> Signed-off-by:
Himanshu Madhani <himanshu.madhani@cavium.com> Signed-off-by:
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- Apr 20, 2017
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Keith Busch authored
The vectors_per_node is calculated from the remaining available vectors. The current vector starts after pre_vectors, so we need to subtract that from the current to properly account for the number of remaining vectors to assign. Fixes: 3412386b ("irq/affinity: Fix extra vecs calculation") Reported-by:
Andrei Vagin <avagin@virtuozzo.com> Signed-off-by:
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- Apr 13, 2017
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Keith Busch authored
This fixes a math error calculating the extra_vecs. The error assumed only 1 cpu per vector, but the value needs to account for the actual number of cpus per vector in order to get the correct remainder for extra CPU assignment. Fixes: 7bf8222b ("irq/affinity: Fix CPU spread for unbalanced nodes") Reported-by:
Xiaolong Ye <xiaolong.ye@intel.com> Signed-off-by:
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