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| author | alc <alc@FreeBSD.org> | 2004-06-12 20:01:48 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2004-06-12 20:01:48 +0000 |
| commit | f6af690bdeb2e55a1bdabd5af91a8a601955e892 (patch) | |
| tree | 2932c2aa045737086a3494b92d63233e95fbc8c1 /sys | |
| parent | a1214ecb7b3a5536b459a68adb96489226a904ad (diff) | |
| download | FreeBSD-src-f6af690bdeb2e55a1bdabd5af91a8a601955e892.zip FreeBSD-src-f6af690bdeb2e55a1bdabd5af91a8a601955e892.tar.gz | |
In a multiprocessor, the PG_W bit in the pte must be changed atomically.
Otherwise, the setting of the PG_M bit by one processor could be lost if
another processor is simultaneously changing the PG_W bit.
Reviewed by: tegge@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/amd64/amd64/pmap.c | 4 | ||||
| -rw-r--r-- | sys/i386/i386/pmap.c | 3 |
2 files changed, 4 insertions, 3 deletions
diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index d332045..6526987 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -2200,10 +2200,10 @@ pmap_change_wiring(pmap, va, wired) pte = pmap_pte(pmap, va); if (wired && (*pte & PG_W) == 0) { pmap->pm_stats.wired_count++; - *pte |= PG_W; + atomic_set_long(pte, PG_W); } else if (!wired && (*pte & PG_W) != 0) { pmap->pm_stats.wired_count--; - *pte &= ~PG_W; + atomic_clear_long(pte, PG_W); } } diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c index 375cfad..32f3b07 100644 --- a/sys/i386/i386/pmap.c +++ b/sys/i386/i386/pmap.c @@ -178,7 +178,8 @@ __FBSDID("$FreeBSD$"); #define pmap_pte_u(pte) ((*(int *)pte & PG_A) != 0) #define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0) -#define pmap_pte_set_w(pte, v) ((v)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W)) +#define pmap_pte_set_w(pte, v) ((v) ? atomic_set_int((u_int *)(pte), PG_W) : \ + atomic_clear_int((u_int *)(pte), PG_W)) #define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v))) struct pmap kernel_pmap_store; |
