Hi, > -----Original Message----- > From: stable-owner@xxxxxxxxxxxxxxx [mailto:stable-owner@xxxxxxxxxxxxxxx] On Behalf Of Greg Kroah-Hartman > Sent: Wednesday, May 27, 2020 3:53 AM > To: linux-kernel@xxxxxxxxxxxxxxx > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx; Peter Zijlstra (Intel) > <peterz@xxxxxxxxxxxxx>; Lauro Ramos Venancio <lvenanci@xxxxxxxxxx>; Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>; > Mike Galbraith <efault@xxxxxx>; Rik van Riel <riel@xxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; > lwang@xxxxxxxxxx; Ingo Molnar <mingo@xxxxxxxxxx>; Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>; Sasha Levin > <sashal@xxxxxxxxxx> > Subject: [PATCH 4.4 26/65] sched/fair, cpumask: Export for_each_cpu_wrap() > > From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > [ Upstream commit c743f0a5c50f2fcbc628526279cfa24f3dabe182 ] > > 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) <peterz@xxxxxxxxxxxxx> > Cc: Lauro Ramos Venancio <lvenanci@xxxxxxxxxx> > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > Cc: Mike Galbraith <efault@xxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Rik van Riel <riel@xxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: lwang@xxxxxxxxxx > Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > [dj: include only what's added to the cpumask interface, 4.4 doesn't > have them in the scheduler] > Signed-off-by: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > include/linux/cpumask.h | 17 +++++++++++++++++ > lib/cpumask.c | 32 ++++++++++++++++++++++++++++++++ > 2 files changed, 49 insertions(+) This commit also needs the following commits: commit d207af2eab3f8668b95ad02b21930481c42806fd Author: Michael Kelley <mhkelley@xxxxxxxxxxx> Date: Wed Feb 14 02:54:03 2018 +0000 cpumask: Make for_each_cpu_wrap() available on UP as well for_each_cpu_wrap() was originally added in the #else half of a large "#if NR_CPUS == 1" statement, but was omitted in the #if half. This patch adds the missing #if half to prevent compile errors when NR_CPUS is 1. Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx> Signed-off-by: Michael Kelley <mhkelley@xxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: kys@xxxxxxxxxxxxx Cc: martin.petersen@xxxxxxxxxx Cc: mikelley@xxxxxxxxxxxxx Fixes: c743f0a5c50f ("sched/fair, cpumask: Export for_each_cpu_wrap()") Link: http://lkml.kernel.org/r/SN6PR1901MB2045F087F59450507D4FCC17CBF50@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Please apply this commit. Best regards, Nobuhro > > diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h > index bb3a4bb35183..1322883e7b46 100644 > --- a/include/linux/cpumask.h > +++ b/include/linux/cpumask.h > @@ -232,6 +232,23 @@ unsigned int cpumask_local_spread(unsigned int i, int node); > (cpu) = cpumask_next_zero((cpu), (mask)), \ > (cpu) < nr_cpu_ids;) > > +extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); > + > +/** > + * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location > + * @cpu: the (optionally unsigned) integer iterator > + * @mask: the cpumask poiter > + * @start: the start location > + * > + * The implementation does not assume any bit in @mask is set (including @start). > + * > + * After the loop, cpu is >= nr_cpu_ids. > + */ > +#define for_each_cpu_wrap(cpu, mask, start) \ > + for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ > + (cpu) < nr_cpumask_bits; \ > + (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) > + > /** > * for_each_cpu_and - iterate over every cpu in both masks > * @cpu: the (optionally unsigned) integer iterator > diff --git a/lib/cpumask.c b/lib/cpumask.c > index 5a70f6196f57..24f06e7abf92 100644 > --- a/lib/cpumask.c > +++ b/lib/cpumask.c > @@ -42,6 +42,38 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) > return i; > } > > +/** > + * cpumask_next_wrap - helper to implement for_each_cpu_wrap > + * @n: the cpu prior to the place to search > + * @mask: the cpumask pointer > + * @start: the start point of the iteration > + * @wrap: assume @n crossing @start terminates the iteration > + * > + * Returns >= nr_cpu_ids on completion > + * > + * Note: the @wrap argument is required for the start condition when > + * we cannot assume @start is set in @mask. > + */ > +int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap) > +{ > + int next; > + > +again: > + next = cpumask_next(n, mask); > + > + if (wrap && n < start && next >= start) { > + return nr_cpumask_bits; > + > + } else if (next >= nr_cpumask_bits) { > + wrap = true; > + n = -1; > + goto again; > + } > + > + return next; > +} > +EXPORT_SYMBOL(cpumask_next_wrap); > + > /* These are not inline because of header tangles. */ > #ifdef CONFIG_CPUMASK_OFFSTACK > /** > -- > 2.25.1 > >
