diff options
| author | Martin Pieuchot <mpi@cvs.openbsd.org> | 2022-06-30 20:28:43 +0000 |
|---|---|---|
| committer | Martin Pieuchot <mpi@cvs.openbsd.org> | 2022-06-30 20:28:43 +0000 |
| commit | abeab691a0b88dc078281874f7de0fe683cfecbd (patch) | |
| tree | 1e2e0f26d54030d23b1fcbf4df392db289872bfe | |
| parent | 355e9fa4e24a4e95e8002972a0d2f9b45fd52b73 (diff) | |
Reduce allocations and possible failures in uvm_pagermapin/out().
. If a direct map exists use it to map single-page allocations
. Use pmap_kenter_pa() instead of pmap_enter() in all other cases.
This speeds up file-based mmap up to 75% when I/O are performed and it
also reduces possible allocations failtures in the page daemon making
it more stable in OOM situations.
ok kettenis@, beck@
| -rw-r--r-- | sys/uvm/uvm_pager.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/sys/uvm/uvm_pager.c b/sys/uvm/uvm_pager.c index 4f8a96c77de..1ff94989165 100644 --- a/sys/uvm/uvm_pager.c +++ b/sys/uvm/uvm_pager.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uvm_pager.c,v 1.81 2022/06/28 19:07:40 mpi Exp $ */ +/* $OpenBSD: uvm_pager.c,v 1.82 2022/06/30 20:28:42 mpi Exp $ */ /* $NetBSD: uvm_pager.c,v 1.36 2000/11/27 18:26:41 chs Exp $ */ /* @@ -258,6 +258,16 @@ uvm_pagermapin(struct vm_page **pps, int npages, int flags) vsize_t size; struct vm_page *pp; +#ifdef __HAVE_PMAP_DIRECT + /* use direct mappings for single page */ + if (npages == 1) { + KASSERT(pps[0]); + KASSERT(pps[0]->pg_flags & PG_BUSY); + kva = pmap_map_direct(pps[0]); + return kva; + } +#endif + prot = PROT_READ; if (flags & UVMPAGER_MAPIN_READ) prot |= PROT_WRITE; @@ -273,14 +283,7 @@ uvm_pagermapin(struct vm_page **pps, int npages, int flags) pp = *pps++; KASSERT(pp); KASSERT(pp->pg_flags & PG_BUSY); - /* Allow pmap_enter to fail. */ - if (pmap_enter(pmap_kernel(), cva, VM_PAGE_TO_PHYS(pp), - prot, PMAP_WIRED | PMAP_CANFAIL | prot) != 0) { - pmap_remove(pmap_kernel(), kva, cva); - pmap_update(pmap_kernel()); - uvm_pseg_release(kva); - return 0; - } + pmap_kenter_pa(cva, VM_PAGE_TO_PHYS(pp), prot); } pmap_update(pmap_kernel()); return kva; @@ -294,8 +297,15 @@ uvm_pagermapin(struct vm_page **pps, int npages, int flags) void uvm_pagermapout(vaddr_t kva, int npages) { +#ifdef __HAVE_PMAP_DIRECT + /* use direct mappings for single page */ + if (npages == 1) { + pmap_unmap_direct(kva); + return; + } +#endif - pmap_remove(pmap_kernel(), kva, kva + ((vsize_t)npages << PAGE_SHIFT)); + pmap_kremove(kva, (vsize_t)npages << PAGE_SHIFT); pmap_update(pmap_kernel()); uvm_pseg_release(kva); |