Andrea Arcangeli a458b76a41 mm: gup: pack has_pinned in MMF_HAS_PINNED ... has_pinned 32bit can be packed in the MMF_HAS_PINNED bit as a noop cleanup. Any atomic_inc/dec to the mm cacheline shared by all threads in pin-fast would reintroduce a loss of SMP scalability to pin-fast, so there's no future potential usefulness to keep an atomic in the mm for this. set_bit(MMF_HAS_PINNED) will be theoretically a bit slower than WRITE_ONCE (atomic_set is equivalent to WRITE_ONCE), but the set_bit (just like atomic_set after this commit) has to be still issued only once per "mm", so the difference between the two will be lost in the noise. will-it-scale "mmap2" shows no change in performance with enterprise config as expected. will-it-scale "pin_fast" retains the > 4000% SMP scalability performance improvement against upstream as expected. This is a noop as far as overall performance and SMP scalability are concerned. [peterx@redhat.com: pack has_pinned in MMF_HAS_PINNED] Link: https://lkml.kernel.org/r/YJqWESqyxa8OZA+2@t490s [akpm@linux-foundation.org: coding style fixes] [peterx@redhat.com: fix build for task_mmu.c, introduce mm_set_has_pinned_flag, fix comments] Link: https://lkml.kernel.org/r/20210507150553.208763-4-peterx@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Kirill Shutemov <kirill@shutemov.name> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2021-06-29 10:53:48 -07:00
..
autogroup.h
clock.h
coredump.h	mm: gup: pack has_pinned in MMF_HAS_PINNED	2021-06-29 10:53:48 -07:00
cpufreq.h
cputime.h
deadline.h
debug.h
hotplug.h
idle.h
init.h
isolation.h
jobctl.h
loadavg.h
mm.h	mm: honor PF_MEMALLOC_PIN for all movable pages	2021-05-05 11:27:26 -07:00
nohz.h
numa_balancing.h
prio.h	sched: Remove USER_PRIO, TASK_USER_PRIO and MAX_USER_PRIO	2021-02-17 14:08:17 +01:00
rt.h
sd_flags.h
signal.h	signal: Factor force_sig_perf out of perf_sigtrap	2021-05-18 16:20:54 -05:00
smt.h
stat.h
sysctl.h	sched: Warn on long periods of pending need_resched	2021-04-21 13:55:41 +02:00
task_stack.h
task.h	kernel: provide create_io_thread() helper	2021-03-04 15:45:03 -07:00
topology.h
types.h
user.h	fanotify: configurable limits via sysfs	2021-03-16 16:49:31 +01:00
wake_q.h
xacct.h