From: Jes Sorensen On larger systems, the amount of output dumped on the console when you do SysRq-M is beyond insane. This patch is trying to reduce it somewhat as even with the smaller NUMA systems that have hit the desktop this seems to be a fair thing to do. The philosophy I have taken is as follows: 1) If a zone is empty, don't tell, we don't need yet another line telling us so. The information is available since one can look up the fact how many zones were initialized in the first place. 2) Put as much information on a line is possible, if it can be done in one line, rahter than two, then do it in one. I tried to format the temperature stuff for easy reading. Change show_free_areas() to not print lines for empty zones. If no zone output is printed, the zone is empty. This reduces the number of lines dumped to the console in sysrq on a large system by several thousand lines. Change the zone temperature printouts to use one line per CPU instead of two lines (one hot, one cold). On a 1024 CPU, 1024 node system, this reduces the console output by over a million lines of output. While this is a bigger problem on large NUMA systems, it is also applicable to smaller desktop sized and mid range NUMA systems. Signed-off-by: Jes Sorensen Signed-off-by: Andrew Morton --- mm/page_alloc.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) diff -puN mm/page_alloc.c~condense-output-of-show_free_areas mm/page_alloc.c --- a/mm/page_alloc.c~condense-output-of-show_free_areas +++ a/mm/page_alloc.c @@ -1297,34 +1297,30 @@ void si_meminfo_node(struct sysinfo *val */ void show_free_areas(void) { - int cpu, temperature; + int cpu; unsigned long active; unsigned long inactive; unsigned long free; struct zone *zone; for_each_zone(zone) { - show_node(zone); - printk("%s per-cpu:", zone->name); - - if (!populated_zone(zone)) { - printk(" empty\n"); + if (!populated_zone(zone)) continue; - } else - printk("\n"); + + show_node(zone); + printk("%s per-cpu:\n", zone->name); for_each_online_cpu(cpu) { struct per_cpu_pageset *pageset; pageset = zone_pcp(zone, cpu); - for (temperature = 0; temperature < 2; temperature++) - printk("cpu %d %s: high %d, batch %d used:%d\n", - cpu, - temperature ? "cold" : "hot", - pageset->pcp[temperature].high, - pageset->pcp[temperature].batch, - pageset->pcp[temperature].count); + printk("CPU %4d: Hot: hi:%5d, btch:%4d usd:%4d " + "Cold: hi:%5d, btch:%4d usd:%4d\n", + cpu, pageset->pcp[0].high, + pageset->pcp[0].batch, pageset->pcp[0].count, + pageset->pcp[1].high, pageset->pcp[1].batch, + pageset->pcp[1].count); } } @@ -1346,6 +1342,9 @@ void show_free_areas(void) for_each_zone(zone) { int i; + if (!populated_zone(zone)) + continue; + show_node(zone); printk("%s" " free:%lukB" @@ -1378,12 +1377,11 @@ void show_free_areas(void) for_each_zone(zone) { unsigned long nr[MAX_ORDER], flags, order, total = 0; + if (!populated_zone(zone)) + continue; + show_node(zone); printk("%s: ", zone->name); - if (!populated_zone(zone)) { - printk("empty\n"); - continue; - } spin_lock_irqsave(&zone->lock, flags); for (order = 0; order < MAX_ORDER; order++) { _