Re: [RFC v7 PATCH 2/4] mm: mmap: zap pages with read mmap_sem in munmap

On 8/10/18 10:57 AM, Matthew Wilcox wrote: On Fri, Aug 10, 2018 at 07:36:01AM +0800, Yang Shi wrote: +/* + * Zap pages with read mmap_sem held + * + * uf is the list for userfaultfd + */ +static int do_munmap_zap_rlock(struct mm_struct *mm, unsigned long start, +

Re: [RFC v7 PATCH 2/4] mm: mmap: zap pages with read mmap_sem in munmap

On Fri, Aug 10, 2018 at 07:36:01AM +0800, Yang Shi wrote: > +/* > + * Zap pages with read mmap_sem held > + * > + * uf is the list for userfaultfd > + */ > +static int do_munmap_zap_rlock(struct mm_struct *mm, unsigned long start, > +size_t len, struct list_head *uf) I

[RFC v7 PATCH 2/4] mm: mmap: zap pages with read mmap_sem in munmap

When running some mmap/munmap scalability tests with large memory (i.e. > 300GB), the below hung task issue may happen occasionally. INFO: task ps:14018 blocked for more than 120 seconds. Tainted: GE 4.9.79-009.ali3000.alios7.x86_64 #1 "echo 0 > /proc/sys/kernel/hung_task_timeo