[PATCH] add memory.vmscan_stat commit log of commit 0ae5e89 " memcg: count the soft_limit reclaim in..." says it adds scanning stats to memory.stat file. But it doesn't because we considered we needed to make a concensus for such new APIs. This patch is a trial to add memory.scan_stat. This shows - the number of scanned pages(total, anon, file) - the number of rotated pages(total, anon, file) - the number of freed pages(total, anon, file) - the number of elaplsed time (including sleep/pause time) for both of direct/soft reclaim. The biggest difference with oringinal Ying's one is that this file can be reset by some write, as # echo 0 ...../memory.scan_stat Example of output is here. This is a result after make -j 6 kernel under 300M limit. [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.scan_stat [kamezawa@bluextal ~]$ cat /cgroup/memory/A/memory.vmscan_stat scanned_pages_by_limit 9471864 scanned_anon_pages_by_limit 6640629 scanned_file_pages_by_limit 2831235 rotated_pages_by_limit 4243974 rotated_anon_pages_by_limit 3971968 rotated_file_pages_by_limit 272006 freed_pages_by_limit 2318492 freed_anon_pages_by_limit 962052 freed_file_pages_by_limit 1356440 elapsed_ns_by_limit 351386416101 scanned_pages_by_system 0 scanned_anon_pages_by_system 0 scanned_file_pages_by_system 0 rotated_pages_by_system 0 rotated_anon_pages_by_system 0 rotated_file_pages_by_system 0 freed_pages_by_system 0 freed_anon_pages_by_system 0 freed_file_pages_by_system 0 elapsed_ns_by_system 0 scanned_pages_by_limit_under_hierarchy 9471864 scanned_anon_pages_by_limit_under_hierarchy 6640629 scanned_file_pages_by_limit_under_hierarchy 2831235 rotated_pages_by_limit_under_hierarchy 4243974 rotated_anon_pages_by_limit_under_hierarchy 3971968 rotated_file_pages_by_limit_under_hierarchy 272006 freed_pages_by_limit_under_hierarchy 2318492 freed_anon_pages_by_limit_under_hierarchy 962052 freed_file_pages_by_limit_under_hierarchy 1356440 elapsed_ns_by_limit_under_hierarchy 351386416101 scanned_pages_by_system_under_hierarchy 0 scanned_anon_pages_by_system_under_hierarchy 0 scanned_file_pages_by_system_under_hierarchy 0 rotated_pages_by_system_under_hierarchy 0 rotated_anon_pages_by_system_under_hierarchy 0 rotated_file_pages_by_system_under_hierarchy 0 freed_pages_by_system_under_hierarchy 0 freed_anon_pages_by_system_under_hierarchy 0 freed_file_pages_by_system_under_hierarchy 0 elapsed_ns_by_system_under_hierarchy 0 total_xxxx is for hierarchy management. This will be useful for further memcg developments and need to be developped before we do some complicated rework on LRU/softlimit management. This patch adds a new struct memcg_scanrecord into scan_control struct. sc->nr_scanned at el is not designed for exporting information. For example, nr_scanned is reset frequentrly and incremented +2 at scanning mapped pages. For avoiding complexity, I added a new param in scan_control which is for exporting scanning score. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Changelog: - fixed the trigger for recording nr_freed in shrink_inactive_list() Changelog: - renamed as vmscan_stat - handle file/anon - added "rotated" - changed names of param in vmscan_stat. --- Documentation/cgroups/memory.txt | 85 +++++++++++++++++++ include/linux/memcontrol.h | 19 ++++ include/linux/swap.h | 6 - mm/memcontrol.c | 172 +++++++++++++++++++++++++++++++++++++-- mm/vmscan.c | 39 +++++++- 5 files changed, 303 insertions(+), 18 deletions(-) Index: mmotm-0710/Documentation/cgroups/memory.txt =================================================================== --- mmotm-0710.orig/Documentation/cgroups/memory.txt +++ mmotm-0710/Documentation/cgroups/memory.txt @@ -380,7 +380,7 @@ will be charged as a new owner of it. 5.2 stat file -memory.stat file includes following statistics +5.2.1 memory.stat file includes following statistics # per-memory cgroup local status cache - # of bytes of page cache memory. @@ -438,6 +438,89 @@ Note: file_mapped is accounted only when the memory cgroup is owner of page cache.) +5.2.2 memory.vmscan_stat + +memory.vmscan_stat includes statistics information for memory scanning and +freeing, reclaiming. The statistics shows memory scanning information since +memory cgroup creation and can be reset to 0 by writing 0 as + + #echo 0 > ../memory.vmscan_stat + +This file contains following statistics. + +[param]_[file_or_anon]_pages_by_[reason]_[under_heararchy] +[param]_elapsed_ns_by_[reason]_[under_hierarchy] + +For example, + + scanned_file_pages_by_limit indicates the number of scanned + file pages at vmscan. + +Now, 3 parameters are supported + + scanned - the number of pages scanned by vmscan + rotated - the number of pages activated at vmscan + freed - the number of pages freed by vmscan + +If "rotated" is high against scanned/freed, the memcg seems busy. + +Now, 2 reason are supported + + limit - the memory cgroup's limit + system - global memory pressure + softlimit + (global memory pressure not under softlimit is not handled now) + +When under_hierarchy is added in the tail, the number indicates the +total memcg scan of its children and itself. + +elapsed_ns is a elapsed time in nanosecond. This may include sleep time +and not indicates CPU usage. So, please take this as just showing +latency. + +Here is an example. + +# cat /cgroup/memory/A/memory.vmscan_stat +scanned_pages_by_limit 9471864 +scanned_anon_pages_by_limit 6640629 +scanned_file_pages_by_limit 2831235 +rotated_pages_by_limit 4243974 +rotated_anon_pages_by_limit 3971968 +rotated_file_pages_by_limit 272006 +freed_pages_by_limit 2318492 +freed_anon_pages_by_limit 962052 +freed_file_pages_by_limit 1356440 +elapsed_ns_by_limit 351386416101 +scanned_pages_by_system 0 +scanned_anon_pages_by_system 0 +scanned_file_pages_by_system 0 +rotated_pages_by_system 0 +rotated_anon_pages_by_system 0 +rotated_file_pages_by_system 0 +freed_pages_by_system 0 +freed_anon_pages_by_system 0 +freed_file_pages_by_system 0 +elapsed_ns_by_system 0 +scanned_pages_by_limit_under_hierarchy 9471864 +scanned_anon_pages_by_limit_under_hierarchy 6640629 +scanned_file_pages_by_limit_under_hierarchy 2831235 +rotated_pages_by_limit_under_hierarchy 4243974 +rotated_anon_pages_by_limit_under_hierarchy 3971968 +rotated_file_pages_by_limit_under_hierarchy 272006 +freed_pages_by_limit_under_hierarchy 2318492 +freed_anon_pages_by_limit_under_hierarchy 962052 +freed_file_pages_by_limit_under_hierarchy 1356440 +elapsed_ns_by_limit_under_hierarchy 351386416101 +scanned_pages_by_system_under_hierarchy 0 +scanned_anon_pages_by_system_under_hierarchy 0 +scanned_file_pages_by_system_under_hierarchy 0 +rotated_pages_by_system_under_hierarchy 0 +rotated_anon_pages_by_system_under_hierarchy 0 +rotated_file_pages_by_system_under_hierarchy 0 +freed_pages_by_system_under_hierarchy 0 +freed_anon_pages_by_system_under_hierarchy 0 +freed_file_pages_by_system_under_hierarchy 0 +elapsed_ns_by_system_under_hierarchy 0 + 5.3 swappiness Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. Index: mmotm-0710/include/linux/memcontrol.h =================================================================== --- mmotm-0710.orig/include/linux/memcontrol.h +++ mmotm-0710/include/linux/memcontrol.h @@ -39,6 +39,16 @@ extern unsigned long mem_cgroup_isolate_ struct mem_cgroup *mem_cont, int active, int file); +struct memcg_scanrecord { + struct mem_cgroup *mem; /* scanend memory cgroup */ + struct mem_cgroup *root; /* scan target hierarchy root */ + int context; /* scanning context (see memcontrol.c) */ + unsigned long nr_scanned[2]; /* the number of scanned pages */ + unsigned long nr_rotated[2]; /* the number of rotated pages */ + unsigned long nr_freed[2]; /* the number of freed pages */ + unsigned long elapsed; /* nsec of time elapsed while scanning */ +}; + #ifdef CONFIG_CGROUP_MEM_RES_CTLR /* * All "charge" functions with gfp_mask should use GFP_KERNEL or @@ -117,6 +127,15 @@ mem_cgroup_get_reclaim_stat_from_page(st extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p); +extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem, + gfp_t gfp_mask, bool noswap, + struct memcg_scanrecord *rec); +extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, + gfp_t gfp_mask, bool noswap, + struct zone *zone, + struct memcg_scanrecord *rec, + unsigned long *nr_scanned); + #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP extern int do_swap_account; #endif Index: mmotm-0710/include/linux/swap.h =================================================================== --- mmotm-0710.orig/include/linux/swap.h +++ mmotm-0710/include/linux/swap.h @@ -253,12 +253,6 @@ static inline void lru_cache_add_file(st /* linux/mm/vmscan.c */ extern unsigned long try_to_free_pages(struct zonelist *zonelist, int order, gfp_t gfp_mask, nodemask_t *mask); -extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem, - gfp_t gfp_mask, bool noswap); -extern unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, - gfp_t gfp_mask, bool noswap, - struct zone *zone, - unsigned long *nr_scanned); extern int __isolate_lru_page(struct page *page, int mode, int file); extern unsigned long shrink_all_memory(unsigned long nr_pages); extern int vm_swappiness; Index: mmotm-0710/mm/memcontrol.c =================================================================== --- mmotm-0710.orig/mm/memcontrol.c +++ mmotm-0710/mm/memcontrol.c @@ -204,6 +204,50 @@ struct mem_cgroup_eventfd_list { static void mem_cgroup_threshold(struct mem_cgroup *mem); static void mem_cgroup_oom_notify(struct mem_cgroup *mem); +enum { + SCAN_BY_LIMIT, + SCAN_BY_SYSTEM, + NR_SCAN_CONTEXT, + SCAN_BY_SHRINK, /* not recorded now */ +}; + +enum { + SCAN, + SCAN_ANON, + SCAN_FILE, + ROTATE, + ROTATE_ANON, + ROTATE_FILE, + FREED, + FREED_ANON, + FREED_FILE, + ELAPSED, + NR_SCANSTATS, +}; + +struct scanstat { + spinlock_t lock; + unsigned long stats[NR_SCAN_CONTEXT][NR_SCANSTATS]; + unsigned long rootstats[NR_SCAN_CONTEXT][NR_SCANSTATS]; +}; + +const char *scanstat_string[NR_SCANSTATS] = { + "scanned_pages", + "scanned_anon_pages", + "scanned_file_pages", + "rotated_pages", + "rotated_anon_pages", + "rotated_file_pages", + "freed_pages", + "freed_anon_pages", + "freed_file_pages", + "elapsed_ns", +}; +#define SCANSTAT_WORD_LIMIT "_by_limit" +#define SCANSTAT_WORD_SYSTEM "_by_system" +#define SCANSTAT_WORD_HIERARCHY "_under_hierarchy" + + /* * The memory controller data structure. The memory controller controls both * page cache and RSS per cgroup. We would eventually like to provide @@ -266,7 +310,8 @@ struct mem_cgroup { /* For oom notifier event fd */ struct list_head oom_notify; - + /* For recording LRU-scan statistics */ + struct scanstat scanstat; /* * Should we move charges of a task when a task is moved into this * mem_cgroup ? And what type of charges should we move ? @@ -1619,6 +1664,44 @@ bool mem_cgroup_reclaimable(struct mem_c } #endif +static void __mem_cgroup_record_scanstat(unsigned long *stats, + struct memcg_scanrecord *rec) +{ + + stats[SCAN] += rec->nr_scanned[0] + rec->nr_scanned[1]; + stats[SCAN_ANON] += rec->nr_scanned[0]; + stats[SCAN_FILE] += rec->nr_scanned[1]; + + stats[ROTATE] += rec->nr_rotated[0] + rec->nr_rotated[1]; + stats[ROTATE_ANON] += rec->nr_rotated[0]; + stats[ROTATE_FILE] += rec->nr_rotated[1]; + + stats[FREED] += rec->nr_freed[0] + rec->nr_freed[1]; + stats[FREED_ANON] += rec->nr_freed[0]; + stats[FREED_FILE] += rec->nr_freed[1]; + + stats[ELAPSED] += rec->elapsed; +} + +static void mem_cgroup_record_scanstat(struct memcg_scanrecord *rec) +{ + struct mem_cgroup *mem; + int context = rec->context; + + if (context >= NR_SCAN_CONTEXT) + return; + + mem = rec->mem; + spin_lock(&mem->scanstat.lock); + __mem_cgroup_record_scanstat(mem->scanstat.stats[context], rec); + spin_unlock(&mem->scanstat.lock); + + mem = rec->root; + spin_lock(&mem->scanstat.lock); + __mem_cgroup_record_scanstat(mem->scanstat.rootstats[context], rec); + spin_unlock(&mem->scanstat.lock); +} + /* * Scan the hierarchy if needed to reclaim memory. We remember the last child * we reclaimed from, so that we don't end up penalizing one child extensively @@ -1643,8 +1726,9 @@ static int mem_cgroup_hierarchical_recla bool noswap = reclaim_options & MEM_CGROUP_RECLAIM_NOSWAP; bool shrink = reclaim_options & MEM_CGROUP_RECLAIM_SHRINK; bool check_soft = reclaim_options & MEM_CGROUP_RECLAIM_SOFT; + struct memcg_scanrecord rec; unsigned long excess; - unsigned long nr_scanned; + unsigned long scanned; excess = res_counter_soft_limit_excess(&root_mem->res) >> PAGE_SHIFT; @@ -1652,6 +1736,15 @@ static int mem_cgroup_hierarchical_recla if (!check_soft && root_mem->memsw_is_minimum) noswap = true; + if (shrink) + rec.context = SCAN_BY_SHRINK; + else if (check_soft) + rec.context = SCAN_BY_SYSTEM; + else + rec.context = SCAN_BY_LIMIT; + + rec.root = root_mem; + while (1) { victim = mem_cgroup_select_victim(root_mem); if (victim == root_mem) { @@ -1692,14 +1785,23 @@ static int mem_cgroup_hierarchical_recla css_put(&victim->css); continue; } + rec.mem = victim; + rec.nr_scanned[0] = 0; + rec.nr_scanned[1] = 0; + rec.nr_rotated[0] = 0; + rec.nr_rotated[1] = 0; + rec.nr_freed[0] = 0; + rec.nr_freed[1] = 0; + rec.elapsed = 0; /* we use swappiness of local cgroup */ if (check_soft) { ret = mem_cgroup_shrink_node_zone(victim, gfp_mask, - noswap, zone, &nr_scanned); - *total_scanned += nr_scanned; + noswap, zone, &rec, &scanned); + *total_scanned += scanned; } else ret = try_to_free_mem_cgroup_pages(victim, gfp_mask, - noswap); + noswap, &rec); + mem_cgroup_record_scanstat(&rec); css_put(&victim->css); /* * At shrinking usage, we can't check we should stop here or @@ -3688,14 +3790,18 @@ try_to_free: /* try to free all pages in this cgroup */ shrink = 1; while (nr_retries && mem->res.usage > 0) { + struct memcg_scanrecord rec; int progress; if (signal_pending(current)) { ret = -EINTR; goto out; } + rec.context = SCAN_BY_SHRINK; + rec.mem = mem; + rec.root = mem; progress = try_to_free_mem_cgroup_pages(mem, GFP_KERNEL, - false); + false, &rec); if (!progress) { nr_retries--; /* maybe some writeback is necessary */ @@ -4539,6 +4645,54 @@ static int mem_control_numa_stat_open(st } #endif /* CONFIG_NUMA */ +static int mem_cgroup_vmscan_stat_read(struct cgroup *cgrp, + struct cftype *cft, + struct cgroup_map_cb *cb) +{ + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); + char string[64]; + int i; + + for (i = 0; i < NR_SCANSTATS; i++) { + strcpy(string, scanstat_string[i]); + strcat(string, SCANSTAT_WORD_LIMIT); + cb->fill(cb, string, mem->scanstat.stats[SCAN_BY_LIMIT][i]); + } + + for (i = 0; i < NR_SCANSTATS; i++) { + strcpy(string, scanstat_string[i]); + strcat(string, SCANSTAT_WORD_SYSTEM); + cb->fill(cb, string, mem->scanstat.stats[SCAN_BY_SYSTEM][i]); + } + + for (i = 0; i < NR_SCANSTATS; i++) { + strcpy(string, scanstat_string[i]); + strcat(string, SCANSTAT_WORD_LIMIT); + strcat(string, SCANSTAT_WORD_HIERARCHY); + cb->fill(cb, string, mem->scanstat.rootstats[SCAN_BY_LIMIT][i]); + } + for (i = 0; i < NR_SCANSTATS; i++) { + strcpy(string, scanstat_string[i]); + strcat(string, SCANSTAT_WORD_SYSTEM); + strcat(string, SCANSTAT_WORD_HIERARCHY); + cb->fill(cb, string, mem->scanstat.rootstats[SCAN_BY_SYSTEM][i]); + } + return 0; +} + +static int mem_cgroup_reset_vmscan_stat(struct cgroup *cgrp, + unsigned int event) +{ + struct mem_cgroup *mem = mem_cgroup_from_cont(cgrp); + + spin_lock(&mem->scanstat.lock); + memset(&mem->scanstat.stats, 0, sizeof(mem->scanstat.stats)); + memset(&mem->scanstat.rootstats, 0, sizeof(mem->scanstat.rootstats)); + spin_unlock(&mem->scanstat.lock); + return 0; +} + + static struct cftype mem_cgroup_files[] = { { .name = "usage_in_bytes", @@ -4609,6 +4763,11 @@ static struct cftype mem_cgroup_files[] .mode = S_IRUGO, }, #endif + { + .name = "vmscan_stat", + .read_map = mem_cgroup_vmscan_stat_read, + .trigger = mem_cgroup_reset_vmscan_stat, + }, }; #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP @@ -4872,6 +5031,7 @@ mem_cgroup_create(struct cgroup_subsys * atomic_set(&mem->refcnt, 1); mem->move_charge_at_immigrate = 0; mutex_init(&mem->thresholds_lock); + spin_lock_init(&mem->scanstat.lock); return &mem->css; free_out: __mem_cgroup_free(mem); Index: mmotm-0710/mm/vmscan.c =================================================================== --- mmotm-0710.orig/mm/vmscan.c +++ mmotm-0710/mm/vmscan.c @@ -105,6 +105,7 @@ struct scan_control { /* Which cgroup do we reclaim from */ struct mem_cgroup *mem_cgroup; + struct memcg_scanrecord *memcg_record; /* * Nodemask of nodes allowed by the caller. If NULL, all nodes @@ -1307,6 +1308,8 @@ putback_lru_pages(struct zone *zone, str int file = is_file_lru(lru); int numpages = hpage_nr_pages(page); reclaim_stat->recent_rotated[file] += numpages; + if (!scanning_global_lru(sc)) + sc->memcg_record->nr_rotated[file] += numpages; } if (!pagevec_add(&pvec, page)) { spin_unlock_irq(&zone->lru_lock); @@ -1350,6 +1353,10 @@ static noinline_for_stack void update_is reclaim_stat->recent_scanned[0] += *nr_anon; reclaim_stat->recent_scanned[1] += *nr_file; + if (!scanning_global_lru(sc)) { + sc->memcg_record->nr_scanned[0] += *nr_anon; + sc->memcg_record->nr_scanned[1] += *nr_file; + } } /* @@ -1463,6 +1470,9 @@ shrink_inactive_list(unsigned long nr_to nr_reclaimed += shrink_page_list(&page_list, zone, sc); } + if (!scanning_global_lru(sc)) + sc->memcg_record->nr_freed[file] += nr_reclaimed; + local_irq_disable(); if (current_is_kswapd()) __count_vm_events(KSWAPD_STEAL, nr_reclaimed); @@ -1562,6 +1572,8 @@ static void shrink_active_list(unsigned } reclaim_stat->recent_scanned[file] += nr_taken; + if (!scanning_global_lru(sc)) + sc->memcg_record->nr_scanned[file] += nr_taken; __count_zone_vm_events(PGREFILL, zone, pgscanned); if (file) @@ -1613,6 +1625,8 @@ static void shrink_active_list(unsigned * get_scan_ratio. */ reclaim_stat->recent_rotated[file] += nr_rotated; + if (!scanning_global_lru(sc)) + sc->memcg_record->nr_rotated[file] += nr_rotated; move_active_pages_to_lru(zone, &l_active, LRU_ACTIVE + file * LRU_FILE); @@ -2207,9 +2229,10 @@ unsigned long try_to_free_pages(struct z #ifdef CONFIG_CGROUP_MEM_RES_CTLR unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *mem, - gfp_t gfp_mask, bool noswap, - struct zone *zone, - unsigned long *nr_scanned) + gfp_t gfp_mask, bool noswap, + struct zone *zone, + struct memcg_scanrecord *rec, + unsigned long *scanned) { struct scan_control sc = { .nr_scanned = 0, @@ -2219,7 +2242,9 @@ unsigned long mem_cgroup_shrink_node_zon .may_swap = !noswap, .order = 0, .mem_cgroup = mem, + .memcg_record = rec, }; + unsigned long start, end; sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); @@ -2228,6 +2253,7 @@ unsigned long mem_cgroup_shrink_node_zon sc.may_writepage, sc.gfp_mask); + start = sched_clock(); /* * NOTE: Although we can get the priority field, using it * here is not a good idea, since it limits the pages we can scan. @@ -2236,19 +2262,25 @@ unsigned long mem_cgroup_shrink_node_zon * the priority and make it zero. */ shrink_zone(0, zone, &sc); + end = sched_clock(); + + if (rec) + rec->elapsed += end - start; + *scanned = sc.nr_scanned; trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed); - *nr_scanned = sc.nr_scanned; return sc.nr_reclaimed; } unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont, gfp_t gfp_mask, - bool noswap) + bool noswap, + struct memcg_scanrecord *rec) { struct zonelist *zonelist; unsigned long nr_reclaimed; + unsigned long start, end; int nid; struct scan_control sc = { .may_writepage = !laptop_mode, @@ -2257,6 +2289,7 @@ unsigned long try_to_free_mem_cgroup_pag .nr_to_reclaim = SWAP_CLUSTER_MAX, .order = 0, .mem_cgroup = mem_cont, + .memcg_record = rec, .nodemask = NULL, /* we don't care the placement */ .gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK), @@ -2265,6 +2298,7 @@ unsigned long try_to_free_mem_cgroup_pag .gfp_mask = sc.gfp_mask, }; + start = sched_clock(); /* * Unlike direct reclaim via alloc_pages(), memcg's reclaim doesn't * take care of from where we get pages. So the node where we start the @@ -2279,6 +2313,9 @@ unsigned long try_to_free_mem_cgroup_pag sc.gfp_mask); nr_reclaimed = do_try_to_free_pages(zonelist, &sc, &shrink); + end = sched_clock(); + if (rec) + rec->elapsed += end - start; trace_mm_vmscan_memcg_reclaim_end(nr_reclaimed); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>