diff options
| author | Alexander Kuleshov <kuleshovmail@gmail.com> | 2016-01-30 14:01:12 +0600 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-01-30 09:20:55 +0100 |
| commit | 5e9ebbd87a99ecc6abb74325b0ac63c46891f6f3 (patch) | |
| tree | e34b02c5146bcd897c46a9044f8679a22d6afda3 | |
| parent | 26cd83670f2f5a3d5b5514a1f7d96567cdb9558b (diff) | |
x86/boot: Micro-optimize reset_early_page_tables()
Save 25 bytes of code and make the bootup a tiny bit faster:
text data bss dec filename
9735144 4970776 15474688 30180608 vmlinux.old
9735119 4970776 15474688 30180583 vmlinux
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1454140872-16926-1-git-send-email-kuleshovmail@gmail.com
[ Fixed various small details. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/head64.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index f129a9af6357..35843caa4ea7 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -40,13 +40,8 @@ pmdval_t early_pmd_flags = __PAGE_KERNEL_LARGE & ~(_PAGE_GLOBAL | _PAGE_NX); /* Wipe all early page tables except for the kernel symbol map */ static void __init reset_early_page_tables(void) { - unsigned long i; - - for (i = 0; i < PTRS_PER_PGD-1; i++) - early_level4_pgt[i].pgd = 0; - + memset(early_level4_pgt, 0, sizeof(pgd_t)*(PTRS_PER_PGD-1)); next_early_pgt = 0; - write_cr3(__pa_nodebug(early_level4_pgt)); } @@ -54,7 +49,6 @@ static void __init reset_early_page_tables(void) int __init early_make_pgtable(unsigned long address) { unsigned long physaddr = address - __PAGE_OFFSET; - unsigned long i; pgdval_t pgd, *pgd_p; pudval_t pud, *pud_p; pmdval_t pmd, *pmd_p; @@ -81,8 +75,7 @@ again: } pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++]; - for (i = 0; i < PTRS_PER_PUD; i++) - pud_p[i] = 0; + memset(pud_p, 0, sizeof(pud_p) * PTRS_PER_PUD); *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } pud_p += pud_index(address); @@ -97,8 +90,7 @@ again: } pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++]; - for (i = 0; i < PTRS_PER_PMD; i++) - pmd_p[i] = 0; + memset(pmd_p, 0, sizeof(pmd_p) * PTRS_PER_PMD); *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } pmd = (physaddr & PMD_MASK) + early_pmd_flags; |