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treewide: make "nr_cpu_ids" unsigned

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First, number of CPUs can't be negative number.

Second, different signnnedness leads to suboptimal code in the following
cases:

1)
	kmalloc(nr_cpu_ids * sizeof(X));

"int" has to be sign extended to size_t.

2)
	while (loff_t *pos < nr_cpu_ids)

MOVSXD is 1 byte longed than the same MOV.

Other cases exist as well. Basically compiler is told that nr_cpu_ids
can't be negative which can't be deduced if it is "int".

Code savings on allyesconfig kernel: -3KB

	add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370)
	function                                     old     new   delta
	coretemp_cpu_online                          450     512     +62
	rcu_init_one                                1234    1272     +38
	pci_device_probe                             374     399     +25

				...

	pgdat_reclaimable_pages                      628     556     -72
	select_fallback_rq                           446     369     -77
	task_numa_find_cpu                          1923    1807    -116

Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Alexey Dobriyan 2017-09-08 16:14:18 -07:00 committed by Linus Torvalds
parent ac036f9570
commit 9b130ad5bb
17 changed files with 21 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/arm64/kernel/smp.c
View file

@ -690,7 +690,7 @@ void __init smp_init_cpus(void)
acpi_parse_gic_cpu_interface, 0);
if (cpu_count > nr_cpu_ids)
pr_warn("Number of cores (%d) exceeds configured maximum of %d - clipping\n",
pr_warn("Number of cores (%d) exceeds configured maximum of %u - clipping\n",
cpu_count, nr_cpu_ids);
if (!bootcpu_valid) {

2
arch/powerpc/kernel/paca.c
View file

@ -224,7 +224,7 @@ void __init allocate_pacas(void)
paca = __va(memblock_alloc_base(paca_size, PAGE_SIZE, limit));
memset(paca, 0, paca_size);
printk(KERN_DEBUG "Allocated %u bytes for %d pacas at %p\n",
printk(KERN_DEBUG "Allocated %u bytes for %u pacas at %p\n",
paca_size, nr_cpu_ids, paca);
allocate_lppacas(nr_cpu_ids, limit);

2
arch/powerpc/kernel/setup-common.c
View file

@ -551,7 +551,7 @@ void __init smp_setup_cpu_maps(void)
if (maxcpus > nr_cpu_ids) {
printk(KERN_WARNING
"Partition configured for %d cpus, "
"operating system maximum is %d.\n",
"operating system maximum is %u.\n",
maxcpus, nr_cpu_ids);
maxcpus = nr_cpu_ids;
} else

4
arch/powerpc/sysdev/xive/native.c
View file

@ -511,13 +511,13 @@ static bool xive_parse_provisioning(struct device_node *np)
static void xive_native_setup_pools(void)
{
/* Allocate a pool big enough */
pr_debug("XIVE: Allocating VP block for pool size %d\n", nr_cpu_ids);
pr_debug("XIVE: Allocating VP block for pool size %u\n", nr_cpu_ids);
xive_pool_vps = xive_native_alloc_vp_block(nr_cpu_ids);
if (WARN_ON(xive_pool_vps == XIVE_INVALID_VP))
pr_err("XIVE: Failed to allocate pool VP, KVM might not function\n");
pr_debug("XIVE: Pool VPs allocated at 0x%x for %d max CPUs\n",
pr_debug("XIVE: Pool VPs allocated at 0x%x for %u max CPUs\n",
xive_pool_vps, nr_cpu_ids);
}

2
arch/tile/kernel/setup.c
View file

@ -1200,7 +1200,7 @@ static void __init validate_hv(void)
* We use a struct cpumask for this, so it must be big enough.
*/
if ((smp_height * smp_width) > nr_cpu_ids)
early_panic("Hypervisor %d x %d grid too big for Linux NR_CPUS %d\n",
early_panic("Hypervisor %d x %d grid too big for Linux NR_CPUS %u\n",
smp_height, smp_width, nr_cpu_ids);
#endif

2
arch/x86/kernel/apic/apic.c
View file

@ -2097,7 +2097,7 @@ static int allocate_logical_cpuid(int apicid)
/* Allocate a new cpuid. */
if (nr_logical_cpuids >= nr_cpu_ids) {
WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %i reached. "
WARN_ONCE(1, "APIC: NR_CPUS/possible_cpus limit of %u reached. "
"Processor %d/0x%x and the rest are ignored.\n",
nr_cpu_ids, nr_logical_cpuids, apicid);
return -EINVAL;

2
arch/x86/kernel/setup_percpu.c
View file

@ -168,7 +168,7 @@ void __init setup_per_cpu_areas(void)
unsigned long delta;
int rc;
pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%u nr_node_ids:%d\n",
NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
/*

2
arch/x86/kernel/smpboot.c
View file

@ -1461,7 +1461,7 @@ __init void prefill_possible_map(void)
/* nr_cpu_ids could be reduced via nr_cpus= */
if (possible > nr_cpu_ids) {
pr_warn("%d Processors exceeds NR_CPUS limit of %d\n",
pr_warn("%d Processors exceeds NR_CPUS limit of %u\n",
possible, nr_cpu_ids);
possible = nr_cpu_ids;
}

4
drivers/base/cpu.c
View file

@ -256,9 +256,9 @@ static ssize_t print_cpus_offline(struct device *dev,
buf[n++] = ',';
if (nr_cpu_ids == total_cpus-1)
n += snprintf(&buf[n], len - n, "%d", nr_cpu_ids);
n += snprintf(&buf[n], len - n, "%u", nr_cpu_ids);
else
n += snprintf(&buf[n], len - n, "%d-%d",
n += snprintf(&buf[n], len - n, "%u-%d",
nr_cpu_ids, total_cpus-1);
}

2
drivers/scsi/scsi_debug.c
View file

@ -5465,7 +5465,7 @@ static int sdebug_driver_probe(struct device * dev)
return error;
}
if (submit_queues > nr_cpu_ids) {
pr_warn("%s: trim submit_queues (was %d) to nr_cpu_ids=%d\n",
pr_warn("%s: trim submit_queues (was %d) to nr_cpu_ids=%u\n",
my_name, submit_queues, nr_cpu_ids);
submit_queues = nr_cpu_ids;
}

6
include/linux/cpumask.h
View file

@ -32,15 +32,15 @@ typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
#define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp)
#if NR_CPUS == 1
#define nr_cpu_ids 1
#define nr_cpu_ids 1U
#else
extern int nr_cpu_ids;
extern unsigned int nr_cpu_ids;
#endif
#ifdef CONFIG_CPUMASK_OFFSTACK
/* Assuming NR_CPUS is huge, a runtime limit is more efficient. Also,
* not all bits may be allocated. */
#define nr_cpumask_bits ((unsigned int)nr_cpu_ids)
#define nr_cpumask_bits nr_cpu_ids
#else
#define nr_cpumask_bits ((unsigned int)NR_CPUS)
#endif

2
kernel/rcu/tree.c
View file

@ -4091,7 +4091,7 @@ static void __init rcu_init_geometry(void)
if (rcu_fanout_leaf == RCU_FANOUT_LEAF &&
nr_cpu_ids == NR_CPUS)
return;
pr_info("RCU: Adjusting geometry for rcu_fanout_leaf=%d, nr_cpu_ids=%d\n",
pr_info("RCU: Adjusting geometry for rcu_fanout_leaf=%d, nr_cpu_ids=%u\n",
rcu_fanout_leaf, nr_cpu_ids);
/*

2
kernel/rcu/tree_plugin.h
View file

@ -89,7 +89,7 @@ static void __init rcu_bootup_announce_oddness(void)
if (rcu_fanout_leaf != RCU_FANOUT_LEAF)
pr_info("\tBoot-time adjustment of leaf fanout to %d.\n", rcu_fanout_leaf);
if (nr_cpu_ids != NR_CPUS)
pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
pr_info("\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%u.\n", NR_CPUS, nr_cpu_ids);
#ifdef CONFIG_RCU_BOOST
pr_info("\tRCU priority boosting: priority %d delay %d ms.\n", kthread_prio, CONFIG_RCU_BOOST_DELAY);
#endif

2
kernel/sched/topology.c
View file

@ -473,7 +473,7 @@ static int __init isolated_cpu_setup(char *str)
alloc_bootmem_cpumask_var(&cpu_isolated_map);
ret = cpulist_parse(str, cpu_isolated_map);
if (ret) {
pr_err("sched: Error, all isolcpus= values must be between 0 and %d\n", nr_cpu_ids);
pr_err("sched: Error, all isolcpus= values must be between 0 and %u\n", nr_cpu_ids);
return 0;
}
return 1;

2
kernel/smp.c
View file

@ -550,7 +550,7 @@ static int __init maxcpus(char *str)
early_param("maxcpus", maxcpus);
/* Setup number of possible processor ids */
int nr_cpu_ids __read_mostly = NR_CPUS;
unsigned int nr_cpu_ids __read_mostly = NR_CPUS;
EXPORT_SYMBOL(nr_cpu_ids);
/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */

2
kernel/trace/trace_functions_graph.c
View file

@ -1543,7 +1543,7 @@ fs_initcall(init_graph_tracefs);
static __init int init_graph_trace(void)
{
max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
max_bytes_for_cpu = snprintf(NULL, 0, "%u", nr_cpu_ids - 1);
if (!register_trace_event(&graph_trace_entry_event)) {
pr_warn("Warning: could not register graph trace events\n");

2
mm/slub.c
View file

@ -4232,7 +4232,7 @@ void __init kmem_cache_init(void)
cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL,
slub_cpu_dead);
pr_info("SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d, CPUs=%d, Nodes=%d\n",
pr_info("SLUB: HWalign=%d, Order=%d-%d, MinObjects=%d, CPUs=%u, Nodes=%d\n",
cache_line_size(),
slub_min_order, slub_max_order, slub_min_objects,
nr_cpu_ids, nr_node_ids);