From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 22 Oct 2007 19:51:33 +0100 (BST) From: Hugh Dickins Subject: Re: [RFC] [-mm PATCH] Memory controller fix swap charging context in unuse_pte() In-Reply-To: <4713A2F2.1010408@linux.vnet.ibm.com> Message-ID: References: <20071005041406.21236.88707.sendpatchset@balbir-laptop> <4713A2F2.1010408@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Balbir Singh Cc: Linux MM Mailing List , Linux Containers List-ID: On Mon, 15 Oct 2007, Balbir Singh wrote: > Hugh Dickins wrote: > > > > --- 2.6.23-rc8-mm2/mm/swapfile.c 2007-09-27 12:03:36.000000000 +0100 > > +++ linux/mm/swapfile.c 2007-10-07 14:33:05.000000000 +0100 > > @@ -507,11 +507,23 @@ unsigned int count_swap_pages(int type, > > * just let do_wp_page work it out if a write is requested later - to > > * force COW, vm_page_prot omits write permission from any private vma. > > */ > > -static int unuse_pte(struct vm_area_struct *vma, pte_t *pte, > > +static int unuse_pte(struct vm_area_struct *vma, pmd_t *pmd, > > unsigned long addr, swp_entry_t entry, struct page *page) ... > > I tested this patch and it seems to be working fine. I tried swapoff -a > in the middle of tests consuming swap. Not 100% rigorous, but a good > test nevertheless. > > Tested-by: Balbir Singh Thanks, Balbir. Sorry for the delay. I've not forgotten our agreement that I should be splitting it into before-and-after mem cgroup patches. But it's low priority for me until we're genuinely assigning to a cgroup there. Hope to get back to looking into that tomorrow, but no promises. I think you still see no problem, where I claim that simply omitting the mem charge mods from mm/swap_state.c leads to OOMs? Maybe our difference is because my memhog in the cgroup is using more memory than RAM, not just more memory than allowed to the cgroup. I suspect that arrives at a state (when the swapcache pages are not charged) where it cannot locate the pages it needs to reclaim to stay within its limit. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org