diff options
| author | Alexey Dobriyan <adobriyan@gmail.com> | 2017-09-08 16:14:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-08 18:26:48 -0700 |
| commit | 9b130ad5bb8255ee8534d92d67e12b2a4887eacb (patch) | |
| tree | 125a5e867be6b0dbd4958ca41426e2c733768110 /arch/x86 | |
| parent | ac036f9570a2d318b7d8dbbdbf0e269d7cc68cef (diff) | |
| download | linux-9b130ad5bb8255ee8534d92d67e12b2a4887eacb.tar.gz | |
treewide: make "nr_cpu_ids" unsigned
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>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 2 |
3 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 7834f73efbf1..8315e2f517a7 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -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; diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 6e8fcb6f7e1e..28dafed6c682 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -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); /* diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 54b9e89d4d6b..cd6622c3204e 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -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; } |