From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161210AbWBUXtB (ORCPT ); Tue, 21 Feb 2006 18:49:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161132AbWBUXtB (ORCPT ); Tue, 21 Feb 2006 18:49:01 -0500 Received: from gold.veritas.com ([143.127.12.110]:26020 "EHLO gold.veritas.com") by vger.kernel.org with ESMTP id S1030222AbWBUXs7 (ORCPT ); Tue, 21 Feb 2006 18:48:59 -0500 X-IronPort-AV: i="4.02,135,1139212800"; d="scan'208"; a="55824217:sNHT32900172" Date: Tue, 21 Feb 2006 23:49:47 +0000 (GMT) From: Hugh Dickins X-X-Sender: hugh@goblin.wat.veritas.com To: Linus Torvalds cc: Andrew Morton , Andi Kleen , Robin Holt , Brent Casavant , Christoph Rohland , linux-kernel@vger.kernel.org Subject: [PATCH] tmpfs: fix mount mpol nodelist parsing Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 21 Feb 2006 23:48:59.0370 (UTC) FILETIME=[62A01CA0:01C63741] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I've been dissatisfied with the mpol_nodelist mount option which was added to tmpfs earlier in -rc. Replace it by mpol=policy:nodelist. And it was broken: a nodelist is a comma-separated list of numbers and ranges; the mount options are a comma-separated list of token=values. Whoops, blindly strsep'ing on commas doesn't work so well: since we've no numeric tokens, and unlikely to add them, use that to distinguish. Move the mpol= parsing to shmem_parse_mpol under CONFIG_NUMA, reject all its options as invalid if not NUMA. /proc shows MPOL_PREFERRED as "prefer", so use that name for the policy instead of "preferred". Enforce that mpol=default has no nodelist; that mpol=prefer has one node only; that mpol=bind has a nodelist; but let mpol=interleave use node_online_map if no nodelist given. Describe this in tmpfs.txt. Signed-off-by: Hugh Dickins Acked-by: Robin Holt --- Documentation/filesystems/tmpfs.txt | 23 +++++----- mm/shmem.c | 81 ++++++++++++++++++++++++++++++------ 2 files changed, 82 insertions(+), 22 deletions(-) --- 2.6.16-rc4/Documentation/filesystems/tmpfs.txt 2006-02-18 12:27:18.000000000 +0000 +++ linux/Documentation/filesystems/tmpfs.txt 2006-02-19 19:49:36.000000000 +0000 @@ -79,15 +79,18 @@ that instance in a system with many cpus tmpfs has a mount option to set the NUMA memory allocation policy for -all files in that instance: -mpol=interleave prefers to allocate memory from each node in turn -mpol=default prefers to allocate memory from the local node -mpol=bind prefers to allocate from mpol_nodelist -mpol=preferred prefers to allocate from first node in mpol_nodelist - -The following mount option is used in conjunction with mpol=interleave, -mpol=bind or mpol=preferred: -mpol_nodelist: nodelist suitable for parsing with nodelist_parse. +all files in that instance (if CONFIG_NUMA is enabled) - which can be +adjusted on the fly via 'mount -o remount ...' + +mpol=default prefers to allocate memory from the local node +mpol=prefer:Node prefers to allocate memory from the given Node +mpol=bind:NodeList allocates memory only from nodes in NodeList +mpol=interleave prefers to allocate from each node in turn +mpol=interleave:NodeList allocates from each node of NodeList in turn + +NodeList format is a comma-separated list of decimal numbers and ranges, +a range being two hyphen-separated decimal numbers, the smallest and +largest node numbers in the range. For example, mpol=bind:0-3,5,7,9-15 To specify the initial root directory you can use the following mount @@ -109,4 +112,4 @@ RAM/SWAP in 10240 inodes and it is only Author: Christoph Rohland , 1.12.01 Updated: - Hugh Dickins , 13 March 2005 + Hugh Dickins , 19 February 2006 --- 2.6.16-rc4/mm/shmem.c 2006-02-18 12:28:19.000000000 +0000 +++ linux/mm/shmem.c 2006-02-19 19:49:36.000000000 +0000 @@ -45,6 +45,7 @@ #include #include #include +#include #include #include #include @@ -874,6 +875,51 @@ redirty: } #ifdef CONFIG_NUMA +static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) +{ + char *nodelist = strchr(value, ':'); + int err = 1; + + if (nodelist) { + /* NUL-terminate policy string */ + *nodelist++ = '\0'; + if (nodelist_parse(nodelist, *policy_nodes)) + goto out; + } + if (!strcmp(value, "default")) { + *policy = MPOL_DEFAULT; + /* Don't allow a nodelist */ + if (!nodelist) + err = 0; + } else if (!strcmp(value, "prefer")) { + *policy = MPOL_PREFERRED; + /* Insist on a nodelist of one node only */ + if (nodelist) { + char *rest = nodelist; + while (isdigit(*rest)) + rest++; + if (!*rest) + err = 0; + } + } else if (!strcmp(value, "bind")) { + *policy = MPOL_BIND; + /* Insist on a nodelist */ + if (nodelist) + err = 0; + } else if (!strcmp(value, "interleave")) { + *policy = MPOL_INTERLEAVE; + /* Default to nodes online if no nodelist */ + if (!nodelist) + *policy_nodes = node_online_map; + err = 0; + } +out: + /* Restore string for error message */ + if (nodelist) + *--nodelist = ':'; + return err; +} + static struct page *shmem_swapin_async(struct shared_policy *p, swp_entry_t entry, unsigned long idx) { @@ -926,6 +972,11 @@ shmem_alloc_page(gfp_t gfp, struct shmem return page; } #else +static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes) +{ + return 1; +} + static inline struct page * shmem_swapin(struct shmem_inode_info *info,swp_entry_t entry,unsigned long idx) { @@ -1859,7 +1910,23 @@ static int shmem_parse_options(char *opt { char *this_char, *value, *rest; - while ((this_char = strsep(&options, ",")) != NULL) { + while (options != NULL) { + this_char = options; + for (;;) { + /* + * NUL-terminate this option: unfortunately, + * mount options form a comma-separated list, + * but mpol's nodelist may also contain commas. + */ + options = strchr(options, ','); + if (options == NULL) + break; + options++; + if (!isdigit(*options)) { + options[-1] = '\0'; + break; + } + } if (!*this_char) continue; if ((value = strchr(this_char,'=')) != NULL) { @@ -1910,18 +1977,8 @@ static int shmem_parse_options(char *opt if (*rest) goto bad_val; } else if (!strcmp(this_char,"mpol")) { - if (!strcmp(value,"default")) - *policy = MPOL_DEFAULT; - else if (!strcmp(value,"preferred")) - *policy = MPOL_PREFERRED; - else if (!strcmp(value,"bind")) - *policy = MPOL_BIND; - else if (!strcmp(value,"interleave")) - *policy = MPOL_INTERLEAVE; - else + if (shmem_parse_mpol(value,policy,policy_nodes)) goto bad_val; - } else if (!strcmp(this_char,"mpol_nodelist")) { - nodelist_parse(value, *policy_nodes); } else { printk(KERN_ERR "tmpfs: Bad mount option %s\n", this_char);