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author | Alexey Dobriyan <adobriyan@gmail.com> | 2017-09-09 01:14:18 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-09 03:26:48 +0200 |
commit | 9b130ad5bb8255ee8534d92d67e12b2a4887eacb (patch) | |
tree | 125a5e867be6b0dbd4958ca41426e2c733768110 /arch/powerpc | |
parent | vga: optimise console scrolling (diff) | |
download | linux-9b130ad5bb8255ee8534d92d67e12b2a4887eacb.tar.xz linux-9b130ad5bb8255ee8534d92d67e12b2a4887eacb.zip |
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/powerpc')
-rw-r--r-- | arch/powerpc/kernel/paca.c | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/setup-common.c | 2 | ||||
-rw-r--r-- | arch/powerpc/sysdev/xive/native.c | 4 |
3 files changed, 4 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c index 70f073d6c3b2..2ff2b8a19f71 100644 --- a/arch/powerpc/kernel/paca.c +++ b/arch/powerpc/kernel/paca.c @@ -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); diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 7de73589d8e2..0ac741fae90e 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -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 diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 44f3a25ca630..ebc244b08d67 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -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); } |