user/sven/linux.git/include/linux/cpumask.h, branch v4.9.74

sched/fair, cpumask: Export for_each_cpu_wrap()

2017-07-21T05:42:23Z

commit c6508a39640b9a27fc2bc10cb708152672c82045 upstream. commit c743f0a5c50f2fcbc628526279cfa24f3dabe182 upstream. More users for for_each_cpu_wrap() have appeared. Promote the construct to generic cpumask interface. The implementation is slightly modified to reduce arguments. Signed-off-by: Peter Zijlstra (Intel) Cc: Lauro Ramos Venancio Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: lwang@redhat.com Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Mel Gorman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

cpumask: use nr_cpumask_bits for parsing functions

2017-02-14T23:25:34Z

commit 4d59b6ccf000862beed6fc0765d3209f98a8d8a2 upstream. Commit 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and parsing functions") converted both cpumask printing and parsing functions to use nr_cpu_ids instead of nr_cpumask_bits. While this was okay for the printing functions as it just picked one of the two output formats that we were alternating between depending on a kernel config, doing the same for parsing wasn't okay. nr_cpumask_bits can be either nr_cpu_ids or NR_CPUS. We can always use nr_cpu_ids but that is a variable while NR_CPUS is a constant, so it can be more efficient to use NR_CPUS when we can get away with it. Converting the printing functions to nr_cpu_ids makes sense because it affects how the masks get presented to userspace and doesn't break anything; however, using nr_cpu_ids for parsing functions can incorrectly leave the higher bits uninitialized while reading in these masks from userland. As all testing and comparison functions use nr_cpumask_bits which can be larger than nr_cpu_ids, the parsed cpumasks can erroneously yield false negative results. This made the taskstats interface incorrectly return -EINVAL even when the inputs were correct. Fix it by restoring the parse functions to use nr_cpumask_bits instead of nr_cpu_ids. Link: http://lkml.kernel.org/r/20170206182442.GB31078@htj.duckdns.org Fixes: 513e3d2d11c9 ("cpumask: always use nr_cpu_ids in formatting and parsing functions") Signed-off-by: Tejun Heo Reported-by: Martin Steigerwald Debugged-by: Ben Hutchings Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

cpumask: fix code comment

2016-08-02T23:35:24Z

Fix code comment for cpumask_parse(). Link: http://lkml.kernel.org/r/71aae2c60ae5dae0cf554199ce6aea8f88c69347.1465380581.git.geliangtang@gmail.com Signed-off-by: Geliang Tang Acked-by: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sched: Allow per-cpu kernel threads to run on online && !active

2016-05-06T12:58:22Z

In order to enable symmetric hotplug, we must mirror the online && !active state of cpu-down on the cpu-up side. However, to retain sanity, limit this state to per-cpu kthreads. Aside from the change to set_cpus_allowed_ptr(), which allow moving the per-cpu kthreads on, the other critical piece is the cpu selection for pinned tasks in select_task_rq(). This avoids dropping into select_fallback_rq(). select_fallback_rq() cannot be allowed to select !active cpus because its used to migrate user tasks away. And we do not want to move user tasks onto cpus that are in transition. Requested-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Thomas Gleixner Cc: Lai Jiangshan Cc: Jan H. Schönherr Cc: Oleg Nesterov Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160301152303.GV6356@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner

cpumask: remove incorrect information from comment

2016-03-22T22:36:02Z

Since commit cdfdef75e795 ("cpumask: only allocate nr_cpumask_bits."), this comment above cpumask_size() is no longer relevant. Signed-off-by: Eric Biggers Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/cpu.c: make set_cpu_* static inlines

2016-01-21T01:09:18Z

Almost all callers of the set_cpu_* functions pass an explicit true or false. Making them static inline thus replaces the function calls with a simple set_bit/clear_bit, saving some .text. Signed-off-by: Rasmus Villemoes Acked-by: Rusty Russell Cc: Greg Kroah-Hartman Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/cpu.c: eliminate cpu_*_mask

2016-01-21T01:09:18Z

Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask and cpu_active_mask with macros expanding to expressions of the same type and value, eliminating some indirection. Signed-off-by: Rasmus Villemoes Acked-by: Rusty Russell Cc: Greg Kroah-Hartman Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kernel/cpu.c: export __cpu_*_mask

2016-01-21T01:09:18Z

Exporting the cpumasks __cpu_possible_mask and friends will allow us to remove the extra indirection through the cpu_*_mask variables. It will also allow the set_cpu_* functions to become static inlines, which will give a .text reduction. Signed-off-by: Rasmus Villemoes Acked-by: Rusty Russell Cc: Greg Kroah-Hartman Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cpumask_set_cpu_local_first => cpumask_local_spread, lament

2015-05-28T01:35:20Z

da91309e0a7e (cpumask: Utility function to set n'th cpu...) created a genuinely weird function. I never saw it before, it went through DaveM. (He only does this to make us other maintainers feel better about our own mistakes.) cpumask_set_cpu_local_first's purpose is say "I need to spread things across N online cpus, choose the ones on this numa node first"; you call it in a loop. It can fail. One of the two callers ignores this, the other aborts and fails the device open. It can fail in two ways: allocating the off-stack cpumask, or through a convoluted codepath which AFAICT can only occur if cpu_online_mask changes. Which shouldn't happen, because if cpu_online_mask can change while you call this, it could return a now-offline cpu anyway. It contains a nonsensical test "!cpumask_of_node(numa_node)". This was drawn to my attention by Geert, who said this causes a warning on Sparc. It sets a single bit in a cpumask instead of returning a cpu number, because that's what the callers want. It could be made more efficient by passing the previous cpu rather than an index, but that would be more invasive to the callers. Fixes: da91309e0a7e8966d916a74cce42ed170fde06bf Signed-off-by: Rusty Russell (then rebased) Tested-by: Amir Vadai Acked-by: Amir Vadai Acked-by: David S. Miller

cpumask: resurrect CPU_MASK_CPU0

2015-04-16T03:03:51Z

We removed it in 2f0f267ea072 (cpumask: remove deprecated functions.), but grep shows it still used by MIPS, and not unreasonably. Signed-off-by: Rusty Russell