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Three changes to vm_phys_alloc_seg_contig():

Browse Source 
1. Optimize the order computation.

2. Update the pool for all of the chunks that are removed from the free
   page lists, and not just the first chunk.

3. Simplify the code for returning excess pages to the free page lists.

Reviewed by:	Doug Moore <dougm@rice.edu>
This commit is contained in:
alc 2018-06-29 04:08:14 +00:00
parent 6283552b65
commit 6b67d15c28
1 changed files with 5 additions and 7 deletions
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12
sys/vm/vm_phys.c
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@ -1239,7 +1239,7 @@ vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
KASSERT(powerof2(boundary), ("boundary is not a power of 2"));
vm_domain_free_assert_locked(VM_DOMAIN(seg->domain));
/* Compute the queue that is the best fit for npages. */
for (order = 0; (1 << order) < npages; order++);
order = flsl(npages - 1);
/* Search for a run satisfying the specified conditions. */
size = npages << PAGE_SHIFT;
for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER;
@ -1297,14 +1297,12 @@ vm_phys_alloc_seg_contig(struct vm_phys_seg *seg, u_long npages,
done:
for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
fl = (*seg->free_queues)[m->pool];
vm_freelist_rem(fl, m, m->order);
vm_freelist_rem(fl, m, oind);
if (m->pool != VM_FREEPOOL_DEFAULT)
vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, oind);
}
if (m_ret->pool != VM_FREEPOOL_DEFAULT)
vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
fl = (*seg->free_queues)[m_ret->pool];
vm_phys_split_pages(m_ret, oind, fl, order);
/* Return excess pages to the free lists. */
npages_end = roundup2(npages, 1 << imin(oind, order));
npages_end = roundup2(npages, 1 << oind);
if (npages < npages_end)
vm_phys_free_contig(&m_ret[npages], npages_end - npages);
return (m_ret);