diff options
| author | dyson <dyson@FreeBSD.org> | 1997-03-22 04:28:16 +0000 |
|---|---|---|
| committer | dyson <dyson@FreeBSD.org> | 1997-03-22 04:28:16 +0000 |
| commit | bd6347d78d8bc0690951bb37df7601bc1b705753 (patch) | |
| tree | 1f18e1ab3fbac9b78737d1db88d23b6f2e10e2c0 | |
| parent | 3860b8cd127797c2d283a53fb1310460d1efcc85 (diff) | |
| download | FreeBSD-src-bd6347d78d8bc0690951bb37df7601bc1b705753.zip FreeBSD-src-bd6347d78d8bc0690951bb37df7601bc1b705753.tar.gz | |
Decrease the latency/overhead in the prezero code when there is
an adequate number of prezeroed pages.
| -rw-r--r-- | sys/amd64/amd64/vm_machdep.c | 19 | ||||
| -rw-r--r-- | sys/i386/i386/vm_machdep.c | 19 |
2 files changed, 34 insertions, 4 deletions
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c index 18fda31..376af2a 100644 --- a/sys/amd64/amd64/vm_machdep.c +++ b/sys/amd64/amd64/vm_machdep.c @@ -38,7 +38,7 @@ * * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ - * $Id$ + * $Id: vm_machdep.c,v 1.75 1997/02/22 09:33:01 peter Exp $ */ #include "npx.h" @@ -854,7 +854,22 @@ int vm_page_zero_idle() { vm_page_t m; static int free_rover = 0; - if ((cnt.v_free_count > cnt.v_interrupt_free_min) && +/* XXX + * We stop zeroing pages when there are sufficent prezeroed pages. + * This threshold isn't really needed, except we want to + * bypass unneeded calls to vm_page_list_find, and the + * associated cache flush and latency. The pre-zero will + * still be called when there are significantly more + * non-prezeroed pages than zeroed pages. The threshold + * of half the number of reserved pages is arbitrary, but + * approximately the right amount. Eventually, we should + * perhaps interrupt the zero operation when a process + * is found to be ready to run. + */ + if (((cnt.v_free_count - vm_page_zero_count) > (cnt.v_free_reserved / 2)) && +#ifdef NOT_NEEDED + (cnt.v_free_count > cnt.v_interrupt_free_min) && +#endif (m = vm_page_list_find(PQ_FREE, free_rover))) { --(*vm_page_queues[m->queue].lcnt); TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c index 18fda31..376af2a 100644 --- a/sys/i386/i386/vm_machdep.c +++ b/sys/i386/i386/vm_machdep.c @@ -38,7 +38,7 @@ * * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ - * $Id$ + * $Id: vm_machdep.c,v 1.75 1997/02/22 09:33:01 peter Exp $ */ #include "npx.h" @@ -854,7 +854,22 @@ int vm_page_zero_idle() { vm_page_t m; static int free_rover = 0; - if ((cnt.v_free_count > cnt.v_interrupt_free_min) && +/* XXX + * We stop zeroing pages when there are sufficent prezeroed pages. + * This threshold isn't really needed, except we want to + * bypass unneeded calls to vm_page_list_find, and the + * associated cache flush and latency. The pre-zero will + * still be called when there are significantly more + * non-prezeroed pages than zeroed pages. The threshold + * of half the number of reserved pages is arbitrary, but + * approximately the right amount. Eventually, we should + * perhaps interrupt the zero operation when a process + * is found to be ready to run. + */ + if (((cnt.v_free_count - vm_page_zero_count) > (cnt.v_free_reserved / 2)) && +#ifdef NOT_NEEDED + (cnt.v_free_count > cnt.v_interrupt_free_min) && +#endif (m = vm_page_list_find(PQ_FREE, free_rover))) { --(*vm_page_queues[m->queue].lcnt); TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq); |
