linux/kernel/smp.c, branch v5.7

cpu/hotplug: Move bringup of secondary CPUs out of smp_init()

2020-03-25T11:59:37Z

This is the last direct user of cpu_up() before it can become an internal implementation detail of the cpu subsystem. Signed-off-by: Qais Yousef Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200323135110.30522-17-qais.yousef@arm.com

smp: Allow smp_call_function_single_async() to insert locked csd

2020-03-06T12:42:28Z

Previously we will raise an warning if we want to insert a csd object which is with the LOCK flag set, and if it happens we'll also wait for the lock to be released. However, this operation does not match perfectly with how the function is named - the name with "_async" suffix hints that this function should not block, while we will. This patch changed this behavior by simply return -EBUSY instead of waiting, at the meantime we allow this operation to happen without warning the user to change this into a feature when the caller wants to "insert a csd object, if it's there, just wait for that one". This is pretty safe because in flush_smp_call_function_queue() for async csd objects (where csd->flags&SYNC is zero) we'll first do the unlock then we call the csd->func(). So if we see the csd->flags&LOCK is true in smp_call_function_single_async(), then it's guaranteed that csd->func() will be called after this smp_call_function_single_async() returns -EBUSY. Update the comment of the function too to refect this. Signed-off-by: Peter Xu Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lkml.kernel.org/r/20191216213125.9536-2-peterx@redhat.com

smp: Remove superfluous cond_func check in smp_call_function_many_cond()

2020-01-28T14:43:00Z

It was requested to remove the cond_func check but the follow up patch was overlooked. Remove it now. Fixes: 67719ef25eeb ("smp: Add a smp_cond_func_t argument to smp_call_function_many()") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20200127083915.434tdkztorkklpdu@linutronix.de

smp: Remove allocation mask from on_each_cpu_cond.*()

2020-01-24T19:40:09Z

The allocation mask is no longer used by on_each_cpu_cond() and on_each_cpu_cond_mask() and can be removed. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20200117090137.1205765-4-bigeasy@linutronix.de

smp: Add a smp_cond_func_t argument to smp_call_function_many()

2020-01-24T19:40:09Z

on_each_cpu_cond_mask() allocates a new CPU mask. The newly allocated mask is a subset of the provided mask based on the conditional function. This memory allocation can be avoided by extending smp_call_function_many() with the conditional function and performing the remote function call based on the mask and the conditional function. Rename smp_call_function_many() to smp_call_function_many_cond() and add the smp_cond_func_t argument. If smp_cond_func_t is provided then it is used before invoking the function. Provide smp_call_function_many() with cond_func set to NULL. Let on_each_cpu_cond_mask() use smp_call_function_many_cond(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20200117090137.1205765-3-bigeasy@linutronix.de

smp: Use smp_cond_func_t as type for the conditional function

2020-01-24T19:40:08Z

Use a typdef for the conditional function instead defining it each time in the function prototype. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20200117090137.1205765-2-bigeasy@linutronix.de

smp: Warn on function calls from softirq context

2019-07-20T09:27:16Z

It's clearly documented that smp function calls cannot be invoked from softirq handling context. Unfortunately nothing enforces that or emits a warning. A single function call can be invoked from softirq context only via smp_call_function_single_async(). The only legit context is task context, so add a warning to that effect. Reported-by: luferry Signed-off-by: Peter Zijlstra Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20190718160601.GP3402@hirez.programming.kicks-ass.net

smp: Remove smp_call_function() and on_each_cpu() return values

2019-06-23T12:26:26Z

The return value is fixed. Remove it and amend the callers. [ tglx: Fixup arm/bL_switcher and powerpc/rtas ] Signed-off-by: Nadav Amit Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Tony Luck Cc: Fenghua Yu Cc: Andrew Morton Link: https://lkml.kernel.org/r/20190613064813.8102-2-namit@vmware.com

smp: Do not mark call_function_data as shared

2019-06-23T12:26:25Z

cfd_data is marked as shared, but although it hold pointers to shared data structures, it is private per core. Signed-off-by: Nadav Amit Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: Rik van Riel Link: https://lkml.kernel.org/r/20190613064813.8102-8-namit@vmware.com

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45Z

Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman