- 08 Nov, 2017 1 commit
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Frederic Weisbecker authored
Use lockdep to check that IRQs are enabled or disabled as expected. This way the sanity check only shows overhead when concurrency correctness debug code is enabled. Signed-off-by:
Frederic Weisbecker <frederic@kernel.org> Acked-by:
Thomas Gleixner <tglx@linutronix.de> Cc: David S . Miller <davem@davemloft.net> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1509980490-4285-7-git-send-email-frederic@kernel.org Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 09 Sep, 2017 1 commit
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Alexey Dobriyan authored
First, number of CPUs can't be negative number. Second, different signnnedness leads to suboptimal code in the following cases: 1) kmalloc(nr_cpu_ids * sizeof(X)); "int" has to be sign extended to size_t. 2) while (loff_t *pos < nr_cpu_ids) MOVSXD is 1 byte longed than the same MOV. Other cases exist as well. Basically compiler is told that nr_cpu_ids can't be negative which can't be deduced if it is "int". Code savings on allyesconfig kernel: -3KB add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370) function old new delta coretemp_cpu_online 450 512 +62 rcu_init_one 1234 1272 +38 pci_device_probe 374 399 +25 ... pgdat_reclaimable_pages 628 556 -72 select_fallback_rq 446 369 -77 task_numa_find_cpu 1923 ...
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- 29 Aug, 2017 1 commit
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Ying Huang authored
struct call_single_data is used in IPIs to transfer information between CPUs. Its size is bigger than sizeof(unsigned long) and less than cache line size. Currently it is not allocated with any explicit alignment requirements. This makes it possible for allocated call_single_data to cross two cache lines, which results in double the number of the cache lines that need to be transferred among CPUs. This can be fixed by requiring call_single_data to be aligned with the size of call_single_data. Currently the size of call_single_data is the power of 2. If we add new fields to call_single_data, we may need to add padding to make sure the size of new definition is the power of 2 as well. Fortunately, this is enforced by GCC, which will report bad sizes. To set alignment requirements of call_single_data to the size of call_single_data, a struct definition and a typedef is used. To test the effect of the patch, I used the vm-scalability multiple thread swap test case (swap-w-seq-mt). The test will create multiple threads and each thread will eat memory until all RAM and part of swap is used, so that huge number of IPIs are triggered when unmapping memory. In the test, the throughput of memory writing improves ~5% compared with misaligned call_single_data, because of faster IPIs. Suggested-by:
Peter Zijlstra <peterz@infradead.org> Signed-off-by:
Huang, Ying <ying.huang@intel.com> [ Add call_single_data_t and align with size of call_single_data. ] Signed-off-by:
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- 23 May, 2017 2 commits
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Peter Zijlstra authored
The cpumasks in smp_call_function_many() are private and not subject to concurrency, atomic bitops are pointless and expensive. Signed-off-by:
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Aaron Lu authored
Inter-Processor-Interrupt(IPI) is needed when a page is unmapped and the process' mm_cpumask() shows the process has ever run on other CPUs. page migration, page reclaim all need IPIs. The number of IPI needed to send to different CPUs is especially large for multi-threaded workload since mm_cpumask() is per process. For smp_call_function_many(), whenever a CPU queues a CSD to a target CPU, it will send an IPI to let the target CPU to handle the work. This isn't necessary - we need only send IPI when queueing a CSD to an empty call_single_queue. The reason: flush_smp_call_function_queue() that is called upon a CPU receiving an IPI will empty the queue and then handle all of the CSDs there. So if the target CPU's call_single_queue is not empty, we know that: i. An IPI for the target CPU has already been sent by 'previous queuers'; ii. flush_smp_call_function_queue() hasn't emptied that CPU's queue yet. Thus, it's safe for us to just queue our CSD there without sending an addtional IPI. And for the 'previous queuers', we can limit it to the first queuer. To demonstrate the effect of this patch, a multi-thread workload that spawns 80 threads to equally consume 100G memory is used. This is tested on a 2 node broadwell-EP which has 44cores/88threads and 32G memory. So after 32G memory is used up, page reclaiming starts to happen a lot. With this patch, IPI number dropped 88% and throughput increased about 15% for the above workload. Signed-off-by:
Aaron Lu <aaron.lu@intel.com> Signed-off-by:
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- 02 Mar, 2017 1 commit
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Ingo Molnar authored
We are going to split <linux/sched/idle.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/idle.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by:
Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by:
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- 26 Oct, 2016 3 commits
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Michael Ellerman authored
Currently we don't print anything before starting to bring up secondary CPUs. This can be confusing if it takes a long time to bring up the secondaries, or if the kernel crashes while doing so and produces no further output. On x86 they work around this by detecting when the first secondary CPU comes up and printing a message (see announce_cpu()). But doing it in smp_init() is simpler and works for all arches. Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Reviewed-by:
Borislav Petkov <bp@suse.de> Cc: akpm@osdl.org Cc: jgross@suse.com Cc: ak@linux.intel.com Cc: tim.c.chen@linux.intel.com Cc: len.brown@intel.com Cc: peterz@infradead.org Cc: richard@nod.at Cc: jolsa@redhat.com Cc: boris.ostrovsky@oracle.com Cc: mgorman@techsingularity.net Link: http://lkml.kernel.org/r/1477460275-8266-3-git-send-email-mpe@ellerman.id.au Signed-off-by:
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Michael Ellerman authored
Currently after bringing up secondary CPUs all arches print "Brought up %d CPUs". On x86 they also print the number of nodes that were brought online. It would be nice to also print the number of nodes on other arches. Although we could override smp_announce() on the other ~10 NUMA aware arches, it seems simpler to just always print the number of nodes. On non-NUMA arches there is just always 1 node. Having done that, smp_announce() is no longer weak, and seems small enough to just pull directly into smp_init(). Also update the printing of "%d CPUs" to be smart when an SMP kernel is booted on a single CPU system, or when only one CPU is available, eg: smp: Brought up 2 nodes, 1 CPU Signed-off-by:
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Michael Ellerman authored
This makes all our pr_xxx()'s start with "smp: ", which helps pin down where they come from and generally looks nice. There is actually only one pr_xxx() use in smp.c at the moment, but we will add some more in the next commit. Suggested-by:
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- 22 Sep, 2016 1 commit
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Peter Zijlstra authored
The SMP IPI struct descriptor is allocated on the stack except for the workqueue and lockdep complains: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 110 Comm: kworker/0:1 Not tainted 4.8.0-rc5+ #14 Hardware name: Dell Inc. Precision T3600/0PTTT9, BIOS A13 05/11/2014 Workqueue: events smp_call_on_cpu_callback ... Call Trace: dump_stack register_lock_class ? __lock_acquire __lock_acquire ? __lock_acquire lock_acquire ? process_one_work process_one_work ? process_one_work worker_thread ? process_one_work ? process_one_work kthread ? kthread_create_on_node ret_from_fork So allocate it on the stack too. Signed-off-by:
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- 05 Sep, 2016 2 commits
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Juergen Gross authored
On some hardware models (e.g. Dell Studio 1555 laptop) some hardware related functions (e.g. SMIs) are to be executed on physical CPU 0 only. Instead of open coding such a functionality multiple times in the kernel add a service function for this purpose. This will enable the possibility to take special measures in virtualized environments like Xen, too. Signed-off-by:
Juergen Gross <jgross@suse.com> Signed-off-by:
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Juergen Gross authored
Add generic virtualization support for pinning the current vCPU to a specified physical CPU. As this operation isn't performance critical (a very limited set of operations like BIOS calls and SMIs is expected to need this) just add a hypervisor specific indirection. Signed-off-by:
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- 15 Jul, 2016 1 commit
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Richard Weinberger authored
Install the callbacks via the state machine. They are installed at runtime so smpcfd_prepare_cpu() needs to be invoked by the boot-CPU. Signed-off-by:
Richard Weinberger <richard@nod.at> [ Added the dropped CPU dying case back in. ] Signed-off-by:
Richard Cochran <rcochran@linutronix.de> Signed-off-by:
Anna-Maria Gleixner <anna-maria@linutronix.de> Reviewed-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Davidlohr Bueso <dave@stgolabs> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160713153337.818376366@linutronix.de Signed-off-by:
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- 14 Jun, 2016 1 commit
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Peter Zijlstra authored
This new form allows using hardware assisted waiting. Some hardware (ARM64 and x86) allow monitoring an address for changes, so by providing a pointer we can use this to replace the cpu_relax() with hardware optimized methods in the future. Requested-by:
Will Deacon <will.deacon@arm.com> Suggested-by:
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- 10 Mar, 2016 2 commits
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Davidlohr Bueso authored
We can micro-optimize this call and mildly relax the barrier requirements by relying on ctrl + rmb, keeping the acquire semantics. In addition, this is pretty much the now standard for busy-waiting under such restraints. Signed-off-by:
Davidlohr Bueso <dbueso@suse.de> Acked-by:
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Davidlohr Bueso authored
While the compiler tends to already to it for us (except for csd_unlock), make it explicit. These helpers mainly deal with the ->flags, are short-lived and can be called, for example, from smp_call_function_many(). Signed-off-by:
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- 01 Mar, 2016 1 commit
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Thomas Gleixner authored
In order to let the hotplugged cpu take care of the setup/teardown, we need a seperate hotplug thread. Signed-off-by:
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- 07 Nov, 2015 1 commit
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Mel Gorman authored
mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for backgrou...
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- 19 Apr, 2015 1 commit
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Linus Torvalds authored
Commit 8053871d ("smp: Fix smp_call_function_single_async() locking") fixed the locking for the asynchronous smp-call case, but in the process of moving the lock handling around, one of the error cases ended up not unlocking the call data at all. This went unnoticed on x86, because this is a "caller is buggy" case, where the caller is trying to call a non-existent CPU. But apparently ARM does that (at least under qemu-arm). Bindly doing cross-cpu calls to random CPU's that aren't even online seems a bit fishy, but the error handling was clearly not correct. Simply add the missing "csd_unlock()" to the error path. Reported-and-tested-by:
Guenter Roeck <linux@roeck-us.net> Analyzed-by:
Rabin Vincent <rabin@rab.in> Acked-by:
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- 17 Apr, 2015 1 commit
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Linus Torvalds authored
The current smp_function_call code suffers a number of problems, most notably smp_call_function_single_async() is broken. The problem is that flush_smp_call_function_queue() does csd_unlock() _after_ calling csd->func(). This means that a caller cannot properly synchronize the csd usage as it has to. Change the code to release the csd before calling ->func() for the async case, and put a WARN_ON_ONCE(csd->flags & CSD_FLAG_LOCK) in smp_call_function_single_async() to warn us of improper serialization, because any waiting there can results in deadlocks when called with IRQs disabled. Rename the (currently) unused WAIT flag to SYNCHRONOUS and (re)use it such that we know what to do in flush_smp_call_function_queue(). Rework csd_{,un}lock() to use smp_load_acquire() / smp_store_release() to avoid some full barriers while more clearly providing lock semantics. Finally move the csd maintenance out of generic_exec_single() into its callers for clearer code. Signed-off-by:
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- 19 Sep, 2014 1 commit
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Chuansheng Liu authored
Currently kick_all_cpus_sync() can break non-polling idle cpus thru IPI interrupts. But sometimes we need to break the polling idle cpus immediately to reselect the suitable c-state, also for non-idle cpus, we need to do nothing if we try to wake up them. Here adding one new function wake_up_all_idle_cpus() to let all cpus out of idle based on function wake_up_if_idle(). Signed-off-by:
Chuansheng Liu <chuansheng.liu@intel.com> Signed-off-by:
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- 26 Aug, 2014 1 commit
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Christoph Lameter authored
Replace uses of __get_cpu_var for address calculation with this_cpu_ptr. Cc: akpm@linux-foundation.org Signed-off-by:
Christoph Lameter <cl@linux.com> Signed-off-by:
Tejun Heo <tj@kernel.org>
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- 07 Aug, 2014 1 commit
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Sasha Levin authored
The rarely-executed memry-allocation-failed callback path generates a WARN_ON_ONCE() when smp_call_function_single() succeeds. Presumably it's supposed to warn on failures. Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Gilad Ben-Yossef <gilad@benyossef.com> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Tejun Heo <htejun@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
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- 23 Jun, 2014 1 commit
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Srivatsa S. Bhat authored
There is a race between the CPU offline code (within stop-machine) and the smp-call-function code, which can lead to getting IPIs on the outgoing CPU, *after* it has gone offline. Specifically, this can happen when using smp_call_function_single_async() to send the IPI, since this API allows sending asynchronous IPIs from IRQ disabled contexts. The exact race condition is described below. During CPU offline, in stop-machine, we don't enforce any rule in the _DISABLE_IRQ stage, regarding the order in which the outgoing CPU and the other CPUs disable their local interrupts. Due to this, we can encounter a situation in which an IPI is sent by one of the other CPUs to the outgoing CPU (while it is *still* online), but the outgoing CPU ends up noticing it only *after* it has gone offline. CPU 1 CPU 2 (Online CPU) (CPU going offline) Ente...
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- 16 Jun, 2014 1 commit
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Frederic Weisbecker authored
irq work currently only supports local callbacks. However its code is mostly ready to run remote callbacks and we have some potential user. The full nohz subsystem currently open codes its own remote irq work on top of the scheduler ipi when it wants a CPU to reevaluate its next tick. However this ad hoc solution bloats the scheduler IPI. Lets just extend the irq work subsystem to support remote queuing on top of the generic SMP IPI to handle this kind of user. This shouldn't add noticeable overhead. Suggested-by:
Frederic Weisbecker <fweisbec@gmail.com>
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- 06 Jun, 2014 1 commit
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Srivatsa S. Bhat authored
There is a longstanding problem related to CPU hotplug which causes IPIs to be delivered to offline CPUs, and the smp-call-function IPI handler code prints out a warning whenever this is detected. Every once in a while this (usually harmless) warning gets reported on LKML, but so far it has not been completely fixed. Usually the solution involves finding out the IPI sender and fixing it by adding appropriate synchronization with CPU hotplug. However, while going through one such internal bug reports, I found that there is a significant bug in the receiver side itself (more specifically, in stop-machine) that can lead to this problem even when the sender code is perfectly fine. This patchset fixes that synchronization problem in the CPU hotplug stop-machine code. Patch 1 adds some additional debug code to the smp-call-function framework, to help debug such issues easily. Patch 2 modifies the stop-machine code to ensure that any IPIs that were sent while the target CPU was online, would be noticed and handled by that CPU without fail before it goes offline. Thus, this avoids scenarios where IPIs are received on offline CPUs (as long as the sender uses proper hotplug synchronization). In fact, I debugged the problem by using Patch 1, and found that the payload of the IPI was always the block layer's trigger_softirq() function. But I was not able to find anything wrong with the block layer code. That's when I started looking at the stop-machine code and realized that there is a race-window which makes the IPI _receiver_ the culprit, not the sender. Patch 2 fixes that race and hence this should put an end to most of the hard-to-debug IPI-to-offline-CPU issues. This patch (of 2): Today the smp-call-function code just prints a warning if we get an IPI on an offline CPU. This info is sufficient to let us know that something went wrong, but often it is very hard to debug exactly who sent the IPI and why, from this info alone. In most cases, we get the warning about the IPI to an offline CPU, immediately after the CPU going offline comes out of the stop-machine phase and reenables interrupts. Since all online CPUs participate in stop-machine, the information regarding the sender of the IPI is already lost by the time we exit the stop-machine loop. So even if we dump the stack on each CPU at this point, we won't find anything useful since all of them will show the stack-trace of the stopper thread. So we need a better way to figure out who sent the IPI and why. To achieve this, when we detect an IPI targeted to an offline CPU, loop through the call-single-data linked list and print out the payload (i.e., the name of the function which was supposed to be executed by the target CPU). This would give us an insight as to who might have sent the IPI and help us debug this further. [akpm@linux-foundation.org: correctly suppress warning output on second and later occurrences] Signed-off-by:
Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <mgalbraith@suse.de> Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Signed-off-by:
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- 24 Feb, 2014 6 commits
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Frederic Weisbecker authored
The name __smp_call_function_single() doesn't tell much about the properties of this function, especially when compared to smp_call_function_single(). The comments above the implementation are also misleading. The main point of this function is actually not to be able to embed the csd in an object. This is actually a requirement that result from the purpose of this function which is to raise an IPI asynchronously. As such it can be called with interrupts disabled. And this feature comes at the cost of the caller who then needs to serialize the IPIs on this csd. Lets rename the function and enhance the comments so that they reflect these properties. Suggested-by:Christoph Hellwig <hch@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmai...
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Frederic Weisbecker authored
The main point of calling __smp_call_function_single() is to send an IPI in a pure asynchronous way. By embedding a csd in an object, a caller can send the IPI without waiting for a previous one to complete as is required by smp_call_function_single() for example. As such, sending this kind of IPI can be safe even when irqs are disabled. This flexibility comes at the expense of the caller who then needs to synchronize the csd lifecycle by himself and make sure that IPIs on a single csd are serialized. This is how __smp_call_function_single() works when wait = 0 and this usecase is relevant. Now there don't seem to be any usecase with wait = 1 that can't be covered by smp_call_function_single() instead, which is safer. Lets look at the two possible scenario: 1) The user calls __smp_call_function_single(wait = 1) on a csd embedded in an object. It looks like a nice and convenient pattern at the first sight because we can then retrieve the object from the IPI handler easily. But actually it is a waste of memory space in the object since the csd can be allocated from the stack by smp_call_function_single(wait = 1) and the object can be passed an the IPI argument. Besides that, embedding the csd in an object is more error prone because the caller must take care of the serialization of the IPIs for this csd. 2) The user calls __smp_call_function_single(wait = 1) on a csd that is allocated on the stack. It's ok but smp_call_function_single() can do it as well and it already takes care of the allocation on the stack. Again it's more simple and less error prone. Therefore, using the underscore prepend API version with wait = 1 is a bad pattern and a sign that the caller can do safer and more simple. There was a single user of that which has just been converted. So lets remove this option to discourage further users. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Signed-off-by:
Jens Axboe <axboe@fb.com>
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Frederic Weisbecker authored
Move this function closer to __smp_call_function_single(). These functions have very similar behavior and should be displayed in the same block for clarity. Reviewed-by:
Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Signed-off-by:
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Frederic Weisbecker authored
__smp_call_function_single() and smp_call_function_single() share some code that can be factorized: execute inline when the target is local, check if the target is online, lock the csd, call generic_exec_single(). Lets move the common parts to generic_exec_single(). Reviewed-by:
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Jan Kara authored
Align __smp_call_function_single() with smp_call_function_single() so that it also checks whether requested cpu is still online. Signed-off-by:
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Jan Kara authored
The IPI function llist iteration is open coded. Lets simplify this with using an llist iterator. Also we want to keep the iteration safe against possible csd.llist->next value reuse from the IPI handler. At least the block subsystem used to do such things so lets stay careful and use llist_for_each_entry_safe(). Signed-off-by:
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- 31 Jan, 2014 2 commits
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Roman Gushchin authored
After commit 9a46ad6d ("smp: make smp_call_function_many() use logic similar to smp_call_function_single()"), cfd->cpumask is accessed only in smp_call_function_many(). So there is no more need to copy it into cfd->cpumask_ipi before putting csd into the list. The cpumask_ipi field is obsolete and can be removed. Signed-off-by:
Roman Gushchin <klamm@yandex-team.ru> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Wang YanQing <udknight@gmail.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Shaohua Li <shli@fusionio.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
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Christoph Hellwig authored
Make smp_call_function_single and friends more efficient by using a lockless list. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
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- 15 Nov, 2013 2 commits
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Christoph Hellwig authored
Signed-off-by:
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Christoph Hellwig authored
We've switched over every architecture that supports SMP to it, so remove the new useless config variable. Signed-off-by:
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- 25 Oct, 2013 2 commits
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Jens Axboe authored
blk-mq reuses the request potentially immediately, since the most cache hot is always given out first. This means that rq->csd could be reused between csd->func() being called and csd_unlock() being called. This isn't a problem, since we never use wait == 1 for the smp call function. Add CSD_FLAG_WAIT to be able to tell the difference, retaining the warning for other cases. Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by:Jens Axboe <axboe@kernel.dk>
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Jens Axboe authored
The blk-mq core and the blk-mq null driver uses it. Reviewed-by:
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- 01 Oct, 2013 1 commit
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Borislav Petkov authored
Turn it into (for example): [ 0.073380] x86: Booting SMP configuration: [ 0.074005] .... node #0, CPUs: #1 #2 #3 #4 #5 #6 #7 [ 0.603005] .... node #1, CPUs: #8 #9 #10 #11 #12 #13 #14 #15 [ 1.200005] .... node #2, CPUs: #16 #17 #18 #19 #20 #21 #22 #23 [ 1.796005] .... node #3, CPUs: #24 #25 #26 #27 #28 #29 #30 #31 [ 2.393005] .... node #4, CPUs: #32 #33 #34 #35 #36 #37 #38 #39 [ 2.996005] .... node #5, CPUs: #40 #41 #42 #43 #44 #45 #46 #47 [ 3.600005] .... node #6, CPUs: #48 #49 #50 #51 #52 #53 #54 #55 [ 4.202005] .... node #7, CPUs: #56 #57 #58 #59 #60 #61 #62 #63 [ 4.811005] .... node #8, CPUs: #64 #65 #66 #67 #68 #69 #70 #71 [ 5.421006] .... node #9, CPUs: #72 #73 #74 #75 #76 #77 #78 #79 [ 6.032005] .... node #10, CPUs: #80 #81 #82 #83 #84 #85 #86 #87 [ 6.648006] .... node #11, CPUs: #88 #89 #90 #91 #92 #93 #94 #95 [ 7.262005] .... node #12, CPUs: #96 #97 #98 #99 #100 #101 #102 #103 [ 7.865005] .... node #13, CPUs: #104 #105 #106 #107 #108 #109 #110 #111 [ 8.466005] .... node #14, CPUs: #112 #113 #114 #115 #116 #117 #118 #119 [ 9.073006] .... node #15, CPUs: #120 #121 #122 #123 #124 #125 #126 #127 [ 9.679901] x86: Booted up 16 nodes, 128 CPUs and drop useless elements. Change num_digits() to hpa's division-avoiding, cell-phone-typed version which he went at great lengths and pains to submit on a Saturday evening. Signed-off-by:
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- 11 Sep, 2013 1 commit
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David Daney authored
As in commit f21afc25 ("smp.h: Use local_irq_{save,restore}() in !SMP version of on_each_cpu()"), we don't want to enable irqs if they are not already enabled. I don't know of any bugs currently caused by this unconditional local_irq_enable(), but I want to use this function in MIPS/OCTEON early boot (when we have early_boot_irqs_disabled). This also makes this function have similar semantics to on_each_cpu() which is good in itself. Signed-off-by:
David Daney <david.daney@cavium.com> Cc: Gilad Ben-Yossef <gilad@benyossef.com> Cc: Christoph Lameter <cl@linux.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
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