Re: [PATCH 01/24] mm: update_lru_size warn and reset bad lru_size

2015-03-22 Thread Hugh Dickins
On Mon, 23 Feb 2015, Kirill A. Shutemov wrote: > On Fri, Feb 20, 2015 at 07:51:16PM -0800, Hugh Dickins wrote: > > Though debug kernels have a VM_BUG_ON to help protect from misaccounting > > lru_size, non-debug kernels are liable to wrap it around: and then the > > vast unsigned long size draws pa

Re: [PATCH 01/24] mm: update_lru_size warn and reset bad lru_size

2015-02-23 Thread Kirill A. Shutemov
On Fri, Feb 20, 2015 at 07:51:16PM -0800, Hugh Dickins wrote: > Though debug kernels have a VM_BUG_ON to help protect from misaccounting > lru_size, non-debug kernels are liable to wrap it around: and then the > vast unsigned long size draws page reclaim into a loop of repeatedly > doing nothing on

[PATCH 01/24] mm: update_lru_size warn and reset bad lru_size

2015-02-20 Thread Hugh Dickins
Though debug kernels have a VM_BUG_ON to help protect from misaccounting lru_size, non-debug kernels are liable to wrap it around: and then the vast unsigned long size draws page reclaim into a loop of repeatedly doing nothing on an empty list, without even a cond_resched(). That soft lockup looks