mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-03 15:47:36 +00:00
9b130ad5bb
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> |
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| video | ||
| xen | ||