Messages in this thread | | | Date | Thu, 08 Nov 2018 15:33:06 +0530 | From | Arun KS <> | Subject | Re: [PATCH v3 4/4] mm: Remove managed_page_count spinlock |
| |
On 2018-11-08 14:04, Michal Hocko wrote: > On Thu 08-11-18 13:53:18, Arun KS wrote: >> Now totalram_pages and managed_pages are atomic varibles. No need >> of managed_page_count spinlock. > > As explained earlier. Please add a motivation here. Feel free to reuse > wording from > http://lkml.kernel.org/r/20181107103630.GF2453@dhcp22.suse.cz
Sure. Will add in next spin.
Regards, Arun > >> >> Signed-off-by: Arun KS <arunks@codeaurora.org> >> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> >> Acked-by: Michal Hocko <mhocko@suse.com> >> Acked-by: Vlastimil Babka <vbabka@suse.cz> >> --- >> include/linux/mmzone.h | 6 ------ >> mm/page_alloc.c | 5 ----- >> 2 files changed, 11 deletions(-) >> >> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h >> index e73dc31..c71b4d9 100644 >> --- a/include/linux/mmzone.h >> +++ b/include/linux/mmzone.h >> @@ -428,12 +428,6 @@ struct zone { >> * Write access to present_pages at runtime should be protected by >> * mem_hotplug_begin/end(). Any reader who can't tolerant drift of >> * present_pages should get_online_mems() to get a stable value. >> - * >> - * Read access to managed_pages should be safe because it's unsigned >> - * long. Write access to zone->managed_pages and totalram_pages are >> - * protected by managed_page_count_lock at runtime. Idealy only >> - * adjust_managed_page_count() should be used instead of directly >> - * touching zone->managed_pages and totalram_pages. >> */ >> atomic_long_t managed_pages; >> unsigned long spanned_pages; >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index f8b64cc..26c5e14 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -122,9 +122,6 @@ >> }; >> EXPORT_SYMBOL(node_states); >> >> -/* Protect totalram_pages and zone->managed_pages */ >> -static DEFINE_SPINLOCK(managed_page_count_lock); >> - >> atomic_long_t _totalram_pages __read_mostly; >> EXPORT_SYMBOL(_totalram_pages); >> unsigned long totalreserve_pages __read_mostly; >> @@ -7065,14 +7062,12 @@ static int __init >> cmdline_parse_movablecore(char *p) >> >> void adjust_managed_page_count(struct page *page, long count) >> { >> - spin_lock(&managed_page_count_lock); >> atomic_long_add(count, &page_zone(page)->managed_pages); >> totalram_pages_add(count); >> #ifdef CONFIG_HIGHMEM >> if (PageHighMem(page)) >> totalhigh_pages_add(count); >> #endif >> - spin_unlock(&managed_page_count_lock); >> } >> EXPORT_SYMBOL(adjust_managed_page_count); >> >> -- >> 1.9.1
| |