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Code Issues Releases Activity

protect pbufs and associated counts with a mutex

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This commit is contained in:
Alfred Perlstein 2001-04-13 10:23:32 +00:00
parent 493607117e
commit 2a758ebe58
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=75474
3 changed files with 14 additions and 2 deletions
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2
sys/vm/swap_pager.c
View File

@ -1282,12 +1282,14 @@ swap_pager_putpages(object, m, count, sync, rtvals)
* at this time.
*/
s = splvm();
mtx_lock(&pbuf_mtx);
n -= nsw_wcount_async_max;
if (nsw_wcount_async + n >= 0) {
nsw_wcount_async += n;
nsw_wcount_async_max += n;
wakeup(&nsw_wcount_async);
}
mtx_unlock(&pbuf_mtx);
splx(s);
}

13
sys/vm/vm_pager.c
View File

@ -193,6 +193,7 @@ int pager_map_size = PAGER_MAP_SIZE;
vm_map_t pager_map;
static int bswneeded;
static vm_offset_t swapbkva; /* swap buffers kva */
struct mtx pbuf_mtx;
void
vm_pager_init()
@ -213,6 +214,7 @@ vm_pager_bufferinit()
struct buf *bp;
int i;
mtx_init(&pbuf_mtx, "pbuf mutex", MTX_DEF);
bp = swbuf;
/*
* Now set up swap and physical I/O buffer headers.
@ -379,11 +381,12 @@ getpbuf(pfreecnt)
struct buf *bp;
s = splvm();
mtx_lock(&pbuf_mtx);
for (;;) {
if (pfreecnt) {
while (*pfreecnt == 0) {
tsleep(pfreecnt, PVM, "wswbuf0", 0);
msleep(pfreecnt, &pbuf_mtx, PVM, "wswbuf0", 0);
}
}
@ -392,12 +395,13 @@ getpbuf(pfreecnt)
break;
bswneeded = 1;
tsleep(&bswneeded, PVM, "wswbuf1", 0);
msleep(&bswneeded, &pbuf_mtx, PVM, "wswbuf1", 0);
/* loop in case someone else grabbed one */
}
TAILQ_REMOVE(&bswlist, bp, b_freelist);
if (pfreecnt)
--*pfreecnt;
mtx_unlock(&pbuf_mtx);
splx(s);
initpbuf(bp);
@ -418,7 +422,9 @@ trypbuf(pfreecnt)
struct buf *bp;
s = splvm();
mtx_lock(&pbuf_mtx);
if (*pfreecnt == 0 || (bp = TAILQ_FIRST(&bswlist)) == NULL) {
mtx_unlock(&pbuf_mtx);
splx(s);
return NULL;
}
@ -426,6 +432,7 @@ trypbuf(pfreecnt)
--*pfreecnt;
mtx_unlock(&pbuf_mtx);
splx(s);
initpbuf(bp);
@ -447,6 +454,7 @@ relpbuf(bp, pfreecnt)
int s;
s = splvm();
mtx_lock(&pbuf_mtx);
if (bp->b_rcred != NOCRED) {
crfree(bp->b_rcred);
@ -472,5 +480,6 @@ relpbuf(bp, pfreecnt)
if (++*pfreecnt == 1)
wakeup(pfreecnt);
}
mtx_unlock(&pbuf_mtx);
splx(s);
}

1
sys/vm/vm_pager.h
View File

@ -91,6 +91,7 @@ MALLOC_DECLARE(M_VMPGDATA);
extern vm_map_t pager_map;
extern int pager_map_size;
extern struct pagerops *pagertab[];
extern struct mtx pbuf_mtx;
vm_object_t vm_pager_allocate __P((objtype_t, void *, vm_ooffset_t, vm_prot_t, vm_ooffset_t));
void vm_pager_bufferinit __P((void));