diff options
| author | alc <alc@FreeBSD.org> | 2005-08-19 07:25:40 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2005-08-19 07:25:40 +0000 |
| commit | e4a69a69564c976cfef3991fa2a45685c2ec0edd (patch) | |
| tree | ec892f9b3c85d26979af1e4f5af9aeb551f76d2e /sys/amd64 | |
| parent | 311fa8ec23a5cd1abad920bbd2719466207e6ae1 (diff) | |
| download | FreeBSD-src-e4a69a69564c976cfef3991fa2a45685c2ec0edd.zip FreeBSD-src-e4a69a69564c976cfef3991fa2a45685c2ec0edd.tar.gz | |
Correct a performance bug in revision 1.462. The effect of the bug is to
execute the outer loop in procedures such as pmap_protect() many more times
than necessary.
Reviewed by: tegge
Diffstat (limited to 'sys/amd64')
| -rw-r--r-- | sys/amd64/amd64/pmap.c | 21 |
1 files changed, 7 insertions, 14 deletions
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index d9ead4c..9082832 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -1569,13 +1569,13 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) break; pml4e = pmap_pml4e(pmap, sva); - if (pml4e == 0) { + if ((*pml4e & PG_V) == 0) { va_next = (sva + NBPML4) & ~PML4MASK; continue; } pdpe = pmap_pdpe(pmap, sva); - if (pdpe == 0) { + if ((*pdpe & PG_V) == 0) { va_next = (sva + NBPDP) & ~PDPMASK; continue; } @@ -1586,8 +1586,6 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) va_next = (sva + NBPDR) & ~PDRMASK; pde = pmap_pde(pmap, sva); - if (pde == 0) - continue; ptpaddr = *pde; /* @@ -1724,13 +1722,13 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) for (; sva < eva; sva = va_next) { pml4e = pmap_pml4e(pmap, sva); - if (pml4e == 0) { + if ((*pml4e & PG_V) == 0) { va_next = (sva + NBPML4) & ~PML4MASK; continue; } pdpe = pmap_pdpe(pmap, sva); - if (pdpe == 0) { + if ((*pdpe & PG_V) == 0) { va_next = (sva + NBPDP) & ~PDPMASK; continue; } @@ -1738,8 +1736,6 @@ pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) va_next = (sva + NBPDR) & ~PDRMASK; pde = pmap_pde(pmap, sva); - if (pde == NULL) - continue; ptpaddr = *pde; /* @@ -2263,13 +2259,13 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, break; pml4e = pmap_pml4e(src_pmap, addr); - if (pml4e == 0) { + if ((*pml4e & PG_V) == 0) { va_next = (addr + NBPML4) & ~PML4MASK; continue; } pdpe = pmap_pdpe(src_pmap, addr); - if (pdpe == 0) { + if ((*pdpe & PG_V) == 0) { va_next = (addr + NBPDP) & ~PDPMASK; continue; } @@ -2277,10 +2273,7 @@ pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, vm_size_t len, va_next = (addr + NBPDR) & ~PDRMASK; pde = pmap_pde(src_pmap, addr); - if (pde) - srcptepaddr = *pde; - else - continue; + srcptepaddr = *pde; if (srcptepaddr == 0) continue; |
