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Index: vm_reserv.c
===================================================================
--- vm_reserv.c
+++ vm_reserv.c
@@ -1269,10 +1269,88 @@
}
/*
+ * Determine whether this reservation has free pages that satisfy the given
+ * request for contiguous physical memory. Start searching from the lower
+ * bound, defined by low_index.
+ *
+ * The free page queue lock must be held.
+ */
+static bool
+vm_reserv_test_contig(vm_reserv_t rv, u_long npages, vm_paddr_t low,
+ vm_paddr_t high, u_long alignment, vm_paddr_t boundary)
+{
+ vm_paddr_t pa, size;
+ u_long changes;
+ int bitpos, i, hi, lo;
+
+ vm_reserv_assert_locked(rv);
+ size = npages << PAGE_SHIFT;
+ pa = VM_PAGE_TO_PHYS(&rv->pages[0]);
+ lo = (pa < low) ?
+ ((low + PAGE_MASK - pa) >> PAGE_SHIFT) : 0;
+ i = lo / NBPOPMAP;
+ changes = rv->popmap[i] | ((1UL << (lo % NBPOPMAP)) - 1);
+ hi = lo = -1;
+ for (;;) {
+ /*
+ * "changes" is a bitmask that marks where a new sequence of
+ * 0s or 1s begins in popmap[i], with last bit in popmap[i-1]
+ * considered to be 1 if and only if lo == hi. The bits of
+ * popmap[-1] and popmap[NPOPMAP] are considered all 1s.
+ */
+ changes ^= (changes << 1) | (lo == hi);
+ while (changes != 0) {
+ /*
+ * If the next change marked begins a run of 0s, set
+ * lo to mark that position. Otherwise set hi and
+ * look for a satisfactory first page from lo up to hi.
+ */
+ bitpos = ffsl(changes) - 1;
+ changes ^= 1UL << bitpos;
+ if (lo == hi) {
+ lo = NBPOPMAP * i + bitpos;
+ continue;
+ }
+ hi = NBPOPMAP * i + bitpos;
+ pa = VM_PAGE_TO_PHYS(&rv->pages[lo]);
+ if ((pa & (alignment - 1)) != 0) {
+ /* Skip to next aligned page. */
+ lo += (((pa - 1) | (alignment - 1)) + 1) >>
+ PAGE_SHIFT;
+ if (lo >= VM_LEVEL_0_NPAGES)
+ return (false);
+ pa = VM_PAGE_TO_PHYS(&rv->pages[lo]);
+ }
+ if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) {
+ /* Skip to next boundary-matching page. */
+ lo += (((pa - 1) | (boundary - 1)) + 1) >>
+ PAGE_SHIFT;
+ if (lo >= VM_LEVEL_0_NPAGES)
+ return (false);
+ pa = VM_PAGE_TO_PHYS(&rv->pages[lo]);
+ }
+ if (pa + size > high) {
+ /* The rest of this reservation is too high. */
+ return (false);
+ }
+ if (lo * PAGE_SIZE + size <= hi * PAGE_SIZE)
+ return (true);
+ lo = hi;
+ }
+ if (++i < NPOPMAP)
+ changes = rv->popmap[i];
+ else if (i == NPOPMAP)
+ changes = ~0UL;
+ else
+ return (false);
+ }
+}
+
+/*
* Searches the partially populated reservation queue for the least recently
* changed reservation with free pages that satisfy the given request for
* contiguous physical memory. If a satisfactory reservation is found, it is
- * broken. Returns TRUE if a reservation is broken and FALSE otherwise.
+ * broken. Returns true if a reservation is broken and false otherwise.
*
* The free page queue lock must be held.
*/
@@ -1282,21 +1360,19 @@
{
vm_paddr_t pa, size;
vm_reserv_t rv, rvn;
- int hi, i, lo, low_index, next_free;
if (npages > VM_LEVEL_0_NPAGES - 1)
- return (FALSE);
+ return (false);
size = npages << PAGE_SHIFT;
vm_reserv_domain_lock(domain);
again:
for (rv = TAILQ_FIRST(&vm_rvq_partpop[domain]); rv != NULL; rv = rvn) {
rvn = TAILQ_NEXT(rv, partpopq);
- pa = VM_PAGE_TO_PHYS(&rv->pages[VM_LEVEL_0_NPAGES - 1]);
- if (pa + PAGE_SIZE - size < low) {
+ pa = VM_PAGE_TO_PHYS(&rv->pages[0]);
+ if (pa + VM_LEVEL_0_SIZE - size < low) {
/* This entire reservation is too low; go to next. */
continue;
}
- pa = VM_PAGE_TO_PHYS(&rv->pages[0]);
if (pa + size > high) {
/* This entire reservation is too high; go to next. */
continue;
@@ -1312,73 +1388,19 @@
}
} else
vm_reserv_domain_unlock(domain);
- if (pa < low) {
- /* Start the search for free pages at "low". */
- low_index = (low + PAGE_MASK - pa) >> PAGE_SHIFT;
- i = low_index / NBPOPMAP;
- hi = low_index % NBPOPMAP;
- } else
- i = hi = 0;
- do {
- /* Find the next free page. */
- lo = ffsl(~(((1UL << hi) - 1) | rv->popmap[i]));
- while (lo == 0 && ++i < NPOPMAP)
- lo = ffsl(~rv->popmap[i]);
- if (i == NPOPMAP)
- break;
- /* Convert from ffsl() to ordinary bit numbering. */
- lo--;
- next_free = NBPOPMAP * i + lo;
- pa = VM_PAGE_TO_PHYS(&rv->pages[next_free]);
- KASSERT(pa >= low,
- ("vm_reserv_reclaim_contig: pa is too low"));
- if (pa + size > high) {
- /* The rest of this reservation is too high. */
- break;
- } else if ((pa & (alignment - 1)) != 0 ||
- ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) {
- /*
- * The current page doesn't meet the alignment
- * and/or boundary requirements. Continue
- * searching this reservation until the rest
- * of its free pages are either excluded or
- * exhausted.
- */
- hi = lo + 1;
- if (hi >= NBPOPMAP) {
- hi = 0;
- i++;
- }
- continue;
- }
- /* Find the next used page. */
- hi = ffsl(rv->popmap[i] & ~((1UL << lo) - 1));
- while (hi == 0 && ++i < NPOPMAP) {
- if ((NBPOPMAP * i - next_free) * PAGE_SIZE >=
- size) {
- vm_reserv_reclaim(rv);
- vm_reserv_unlock(rv);
- return (TRUE);
- }
- hi = ffsl(rv->popmap[i]);
- }
- /* Convert from ffsl() to ordinary bit numbering. */
- if (i != NPOPMAP)
- hi--;
- if ((NBPOPMAP * i + hi - next_free) * PAGE_SIZE >=
- size) {
- vm_reserv_reclaim(rv);
- vm_reserv_unlock(rv);
- return (TRUE);
- }
- } while (i < NPOPMAP);
+ if (vm_reserv_test_contig(rv, npages, low, high,
+ alignment, boundary)) {
+ vm_reserv_reclaim(rv);
+ vm_reserv_unlock(rv);
+ return (true);
+ }
vm_reserv_unlock(rv);
vm_reserv_domain_lock(domain);
if (rvn != NULL && !rvn->inpartpopq)
goto again;
}
vm_reserv_domain_unlock(domain);
- return (FALSE);
+ return (false);
}
/*

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