From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263725AbUE3Na6 (ORCPT ); Sun, 30 May 2004 09:30:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263736AbUE3Na6 (ORCPT ); Sun, 30 May 2004 09:30:58 -0400 Received: from mail005.syd.optusnet.com.au ([211.29.132.54]:19604 "EHLO mail005.syd.optusnet.com.au") by vger.kernel.org with ESMTP id S263725AbUE3Naw (ORCPT ); Sun, 30 May 2004 09:30:52 -0400 From: Con Kolivas To: Linux Kernel Mailinglist Subject: [PATCH] Autoregulated VM swappiness Date: Sun, 30 May 2004 23:30:41 +1000 User-Agent: KMail/1.6.1 MIME-Version: 1.0 Content-Disposition: inline Content-Type: Multipart/Mixed; boundary="Boundary-00=_BIeuAGNbQsbnkwl" Message-Id: <200405302330.48595.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --Boundary-00=_BIeuAGNbQsbnkwl Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline =2D----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 With all the recent attention paid to swap I thought I'd resync this patch= =20 with 2.6.7-rc2 in it's more recent incarnation. What this patch does is this: The swappiness is made proportional to the amount of ram consumed by=20 application pages, and inversely proportional to the amount of the last=20 (sizeof physical ram) of swap ram used up. This has the effect of hardly ev= er=20 using swap if you have large amounts of cached data by say copying an iso=20 image or manipulating video files. Conversely if you have lots of=20 applications running at once it will allow the less used ones to swap out b= y=20 increasing the swappiness, giving preference to the "foreground" one.=20 Changes from the first version announced on lkml: Amount of swap space consumed is also taken into account, and the size of i= t=20 compared to the physical ram is taken into consideration when making it's=20 effect on the value of swappiness. With this patch, this should make any=20 machine that has swapspace as resistant to OOM as possible. This version by default autoregulates the swappiness, but also allows you t= o=20 choose a manual setting if you so desire by echo 0 > /proc/sys/vm/autoswappiness and then setting the swappiness the manual way as previously. This makes=20 comparison with autoregulation easy. A few bugfixes. Con =2D----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQFAueIEZUg7+tp6mRURAnx5AJ9bkBsu+nAxT3fXJe2qLQ3PSYVL7wCbBrrC pZOZHLOBhVsVdrd1a1ozKS4=3D =3DXeIZ =2D----END PGP SIGNATURE----- --Boundary-00=_BIeuAGNbQsbnkwl Content-Type: text/x-diff; charset="us-ascii"; name="patch-2.6.7-rc2-am10" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="patch-2.6.7-rc2-am10" diff -Naurp linux-2.6.7-rc2-base/include/linux/swap.h linux-2.6.7-rc2-am9/include/linux/swap.h --- linux-2.6.7-rc2-base/include/linux/swap.h 2004-05-30 17:51:45.896165842 +1000 +++ linux-2.6.7-rc2-am9/include/linux/swap.h 2004-05-30 23:07:34.718254427 +1000 @@ -175,6 +175,7 @@ extern void swap_setup(void); extern int try_to_free_pages(struct zone **, unsigned int, unsigned int); extern int shrink_all_memory(int); extern int vm_swappiness; +extern int auto_swappiness; #ifdef CONFIG_MMU /* linux/mm/shmem.c */ diff -Naurp linux-2.6.7-rc2-base/include/linux/sysctl.h linux-2.6.7-rc2-am9/include/linux/sysctl.h --- linux-2.6.7-rc2-base/include/linux/sysctl.h 2004-05-30 17:51:45.897165687 +1000 +++ linux-2.6.7-rc2-am9/include/linux/sysctl.h 2004-05-30 23:08:29.022809409 +1000 @@ -164,6 +164,7 @@ enum VM_LAPTOP_MODE=23, /* vm laptop mode */ VM_BLOCK_DUMP=24, /* block dump mode */ VM_HUGETLB_GROUP=25, /* permitted hugetlb group */ + VM_AUTO_SWAPPINESS=26, /* Make vm_swappiness autoregulated */ }; diff -Naurp linux-2.6.7-rc2-base/kernel/sysctl.c linux-2.6.7-rc2-am9/kernel/sysctl.c --- linux-2.6.7-rc2-base/kernel/sysctl.c 2004-05-30 17:51:45.978153070 +1000 +++ linux-2.6.7-rc2-am9/kernel/sysctl.c 2004-05-30 23:07:14.588384816 +1000 @@ -727,6 +727,17 @@ static ctl_table vm_table[] = { .extra1 = &zero, .extra2 = &one_hundred, }, + { + .ctl_name = VM_AUTO_SWAPPINESS, + .procname = "autoswappiness", + .data = &auto_swappiness, + .maxlen = sizeof(auto_swappiness), + .mode = 0644, + .proc_handler = &proc_dointvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one_hundred, + }, #ifdef CONFIG_HUGETLB_PAGE { .ctl_name = VM_HUGETLB_PAGES, diff -Naurp linux-2.6.7-rc2-base/mm/vmscan.c linux-2.6.7-rc2-am9/mm/vmscan.c --- linux-2.6.7-rc2-base/mm/vmscan.c 2004-05-30 17:51:46.041143257 +1000 +++ linux-2.6.7-rc2-am9/mm/vmscan.c 2004-05-30 23:07:14.260435815 +1000 @@ -43,6 +43,7 @@ * From 0 .. 100. Higher means more swappy. */ int vm_swappiness = 60; +int auto_swappiness = 1; static long total_memory; #define lru_to_page(_head) (list_entry((_head)->prev, struct page, lru)) @@ -634,6 +635,41 @@ refill_inactive_zone(struct zone *zone, */ mapped_ratio = (ps->nr_mapped * 100) / total_memory; + if (auto_swappiness) { +#ifdef CONFIG_SWAP + int app_percent; + struct sysinfo i; + + si_swapinfo(&i); + + if (likely(i.totalswap >= 100)) { + int swap_centile; + + /* + * app_percent is the percentage of physical ram used + * by application pages. + */ + si_meminfo(&i); + app_percent = 100 - ((i.freeram + get_page_cache_size() - + swapper_space.nrpages) / (i.totalram / 100)); + + /* + * swap_centile is the percentage of the last (sizeof physical + * ram) of swap free. + */ + swap_centile = i.freeswap / + (min(i.totalswap, i.totalram) / 100); + + /* + * Autoregulate vm_swappiness to be equal to the lowest of + * app_percent and swap_centile. -ck + */ + vm_swappiness = min(app_percent, swap_centile); + } else + vm_swappiness = 0; +#endif + } + /* * Now decide how much we really want to unmap some pages. The mapped * ratio is downgraded - just because there's a lot of mapped memory --Boundary-00=_BIeuAGNbQsbnkwl--