From: Eric Dumazet Date: Sun, 5 Feb 2006 07:27:36 +0000 (-0800) Subject: [PATCH] percpu data: only iterate over possible CPUs X-Git-Tag: v2.6.16-rc3~174 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=88a2a4ac6b671a4b0dd5d2d762418904c05f4104;p=linux-2.6-omap-h63xx.git [PATCH] percpu data: only iterate over possible CPUs percpu_data blindly allocates bootmem memory to store NR_CPUS instances of cpudata, instead of allocating memory only for possible cpus. As a preparation for changing that, we need to convert various 0 -> NR_CPUS loops to use for_each_cpu(). (The above only applies to users of asm-generic/percpu.h. powerpc has gone it alone and is presently only allocating memory for present CPUs, so it's currently corrupting memory). Signed-off-by: Eric Dumazet Cc: "David S. Miller" Cc: James Bottomley Acked-by: Ingo Molnar Cc: Jens Axboe Cc: Anton Blanchard Acked-by: William Irwin Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index d661703ac1c..63f39a7e2c9 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -138,7 +138,7 @@ static int __init check_nmi_watchdog(void) if (nmi_watchdog == NMI_LOCAL_APIC) smp_call_function(nmi_cpu_busy, (void *)&endflag, 0, 0); - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_cpu(cpu) prev_nmi_count[cpu] = per_cpu(irq_stat, cpu).__nmi_count; local_irq_enable(); mdelay((10*1000)/nmi_hz); // wait 10 ticks diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index f9fc07efd2d..e5aad831458 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3453,7 +3453,7 @@ int __init blk_dev_init(void) iocontext_cachep = kmem_cache_create("blkdev_ioc", sizeof(struct io_context), 0, SLAB_PANIC, NULL, NULL); - for (i = 0; i < NR_CPUS; i++) + for_each_cpu(i) INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i)); open_softirq(BLOCK_SOFTIRQ, blk_done_softirq, NULL); diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 245ca99a641..c551bb84dbf 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -1245,7 +1245,7 @@ static int __init init_scsi(void) if (error) goto cleanup_sysctl; - for (i = 0; i < NR_CPUS; i++) + for_each_cpu(i) INIT_LIST_HEAD(&per_cpu(scsi_done_q, i)); devfs_mk_dir("scsi"); diff --git a/fs/file.c b/fs/file.c index fd066b261c7..cea7cbea11d 100644 --- a/fs/file.c +++ b/fs/file.c @@ -379,7 +379,6 @@ static void __devinit fdtable_defer_list_init(int cpu) void __init files_defer_init(void) { int i; - /* Really early - can't use for_each_cpu */ - for (i = 0; i < NR_CPUS; i++) + for_each_cpu(i) fdtable_defer_list_init(i); } diff --git a/kernel/sched.c b/kernel/sched.c index f77f23f8f47..839466fdfb4 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6109,7 +6109,7 @@ void __init sched_init(void) runqueue_t *rq; int i, j, k; - for (i = 0; i < NR_CPUS; i++) { + for_each_cpu(i) { prio_array_t *array; rq = cpu_rq(i); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 44b4eb4202d..dde04ff4be3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1213,18 +1213,21 @@ static void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask) { int cpu = 0; - memset(ret, 0, sizeof(*ret)); + memset(ret, 0, nr * sizeof(unsigned long)); cpus_and(*cpumask, *cpumask, cpu_online_map); cpu = first_cpu(*cpumask); while (cpu < NR_CPUS) { unsigned long *in, *out, off; + if (!cpu_isset(cpu, *cpumask)) + continue; + in = (unsigned long *)&per_cpu(page_states, cpu); cpu = next_cpu(cpu, *cpumask); - if (cpu < NR_CPUS) + if (likely(cpu < NR_CPUS)) prefetch(&per_cpu(page_states, cpu)); out = (unsigned long *)ret; @@ -1886,8 +1889,7 @@ static void setup_pagelist_highmark(struct per_cpu_pageset *p, * not check if the processor is online before following the pageset pointer. * Other parts of the kernel may not check if the zone is available. */ -static struct per_cpu_pageset - boot_pageset[NR_CPUS]; +static struct per_cpu_pageset boot_pageset[NR_CPUS]; /* * Dynamically allocate memory for the diff --git a/net/core/dev.c b/net/core/dev.c index ffb82073056..2afb0de9532 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3237,7 +3237,7 @@ static int __init net_dev_init(void) * Initialise the packet receive queues. */ - for (i = 0; i < NR_CPUS; i++) { + for_each_cpu(i) { struct softnet_data *queue; queue = &per_cpu(softnet_data, i); diff --git a/net/core/utils.c b/net/core/utils.c index ac1d1fcf867..fdc4f38bc46 100644 --- a/net/core/utils.c +++ b/net/core/utils.c @@ -121,7 +121,7 @@ void __init net_random_init(void) { int i; - for (i = 0; i < NR_CPUS; i++) { + for_each_cpu(i) { struct nrnd_state *state = &per_cpu(net_rand_state,i); __net_srandom(state, i+jiffies); } @@ -133,7 +133,7 @@ static int net_random_reseed(void) unsigned long seed[NR_CPUS]; get_random_bytes(seed, sizeof(seed)); - for (i = 0; i < NR_CPUS; i++) { + for_each_cpu(i) { struct nrnd_state *state = &per_cpu(net_rand_state,i); __net_srandom(state, seed[i]); } diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c index 39d49dc333a..1b167c4bb3b 100644 --- a/net/ipv4/proc.c +++ b/net/ipv4/proc.c @@ -49,7 +49,7 @@ static int fold_prot_inuse(struct proto *proto) int res = 0; int cpu; - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_cpu(cpu) res += proto->stats[cpu].inuse; return res; diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c index 50a13e75d70..4238b1ed886 100644 --- a/net/ipv6/proc.c +++ b/net/ipv6/proc.c @@ -38,7 +38,7 @@ static int fold_prot_inuse(struct proto *proto) int res = 0; int cpu; - for (cpu=0; cpustats[cpu].inuse; return res; diff --git a/net/socket.c b/net/socket.c index b38a263853c..a00851f981d 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2078,7 +2078,7 @@ void socket_seq_show(struct seq_file *seq) int cpu; int counter = 0; - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_cpu(cpu) counter += per_cpu(sockets_in_use, cpu); /* It can be negative, by the way. 8) */