Re: [PATCH v3 0/6] lib: Extend bitmap find binary operations

[Mathieu Desnoyers]

On 2024-08-30 19:02, Yury Norov wrote:
> On Fri, Aug 30, 2024 at 03:10:37PM -0400, Mathieu Desnoyers wrote:
> > Extend bitmap find.h and cpumask.h with additional binary operations
> > such as "nor".
> >
> > Also extend the testing and benchmark coverage of those bitmap find with
> > binary operations.
> >
> > This is useful for NUMA-aware rseq concurrency IDs which depend on this
> > series. The series can be found at:
> >
> > https://lore.kernel.org/lkml/20240823185946.418340-1-mathieu.desnoyers@xxxxxxxxxxxx/
>
> Added in bitmap-for-next for testing.

Hi Yuri,

FYI, after a lot of performance results analysis on variations over
the NUMA-aware rseq patch, I figured I need to take a drastically
different (and much simpler) approach to solve this in order to improve
cache locality as well, and it turns out I likely won't need the new
bitwise ops added by this series.

So feel free to keep it as a general improvement, or to drop it for
now.

Thanks,

Mathieu

> Thanks,
> Yury
>
> > Mathieu Desnoyers (6):
> >    lib: Clarify comment on top of find_next_andnot_bit
> >    lib: Implement find_{first,next,nth}_nor_bit, for_each_nor_bit,
> >      find_first_andnot_bit
> >    lib: test bitmap sets binary operation iterators
> >    lib: Fix test_find_first_and_bit and test_find_next_and_bit benchmark
> >    lib: benchmark bitmap sets binary operation find
> >    cpumask: Implement cpumask_{first,next}_{nor,andnot}
> >
> >   include/linux/cpumask.h  |  60 ++++++++++++++++
> >   include/linux/find.h     | 124 +++++++++++++++++++++++++++++++--
> >   lib/find_bit.c           |  36 ++++++++++
> >   lib/find_bit_benchmark.c | 143 +++++++++++++++++++++++++++++++++------
> >   lib/test_bitmap.c        |  81 ++++++++++++++++++++++
> >   5 files changed, 418 insertions(+), 26 deletions(-)
> >
> > --
> > 2.39.2

--
Mathieu Desnoyers
EfficiOS Inc.
https://www.efficios.com