Stefano Stabellini
2013-Sep-30 12:06 UTC
[PATCH v2 1/1] xen/arm: map_domain_page: reuse slots with avail == 0
If a slot has avail == 0 but still points to the right mfn, reuse it.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Changes in v2:
- check that the slot which we are about to reuse is valid.
---
xen/arch/arm/mm.c | 17 ++++++++++-------
1 files changed, 10 insertions(+), 7 deletions(-)
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index 44ec0e3..21e20fa 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -232,7 +232,15 @@ void *map_domain_page(unsigned long mfn)
i < DOMHEAP_ENTRIES;
slot = (slot + 1) % DOMHEAP_ENTRIES, i++ )
{
- if ( map[slot].pt.avail == 0 )
+ if ( map[slot].pt.avail < 0xf &&
+ map[slot].pt.base == slot_mfn &&
+ map[slot].pt.valid )
+ {
+ /* This slot already points to the right place; reuse it */
+ map[slot].pt.avail++;
+ break;
+ }
+ else if ( map[slot].pt.avail == 0 )
{
/* Commandeer this 2MB slot */
pte = mfn_to_xen_entry(slot_mfn);
@@ -240,12 +248,7 @@ void *map_domain_page(unsigned long mfn)
write_pte(map + slot, pte);
break;
}
- else if ( map[slot].pt.avail < 0xf && map[slot].pt.base ==
slot_mfn )
- {
- /* This slot already points to the right place; reuse it */
- map[slot].pt.avail++;
- break;
- }
+
}
/* If the map fills up, the callers have misbehaved. */
BUG_ON(i == DOMHEAP_ENTRIES);
--
1.7.2.5
Tim Deegan
2013-Sep-30 12:17 UTC
Re: [PATCH v2 1/1] xen/arm: map_domain_page: reuse slots with avail == 0
At 13:06 +0100 on 30 Sep (1380546372), Stefano Stabellini wrote:> If a slot has avail == 0 but still points to the right mfn, reuse it. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>Acked-by: Tim Deegan <tim@xen.org>> Changes in v2: > - check that the slot which we are about to reuse is valid. > --- > xen/arch/arm/mm.c | 17 ++++++++++------- > 1 files changed, 10 insertions(+), 7 deletions(-) > > diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c > index 44ec0e3..21e20fa 100644 > --- a/xen/arch/arm/mm.c > +++ b/xen/arch/arm/mm.c > @@ -232,7 +232,15 @@ void *map_domain_page(unsigned long mfn) > i < DOMHEAP_ENTRIES; > slot = (slot + 1) % DOMHEAP_ENTRIES, i++ ) > { > - if ( map[slot].pt.avail == 0 ) > + if ( map[slot].pt.avail < 0xf && > + map[slot].pt.base == slot_mfn && > + map[slot].pt.valid ) > + { > + /* This slot already points to the right place; reuse it */ > + map[slot].pt.avail++; > + break; > + } > + else if ( map[slot].pt.avail == 0 ) > { > /* Commandeer this 2MB slot */ > pte = mfn_to_xen_entry(slot_mfn); > @@ -240,12 +248,7 @@ void *map_domain_page(unsigned long mfn) > write_pte(map + slot, pte); > break; > } > - else if ( map[slot].pt.avail < 0xf && map[slot].pt.base == slot_mfn ) > - { > - /* This slot already points to the right place; reuse it */ > - map[slot].pt.avail++; > - break; > - } > + > } > /* If the map fills up, the callers have misbehaved. */ > BUG_ON(i == DOMHEAP_ENTRIES); > -- > 1.7.2.5 >
Ian Campbell
2013-Oct-03 13:38 UTC
Re: [PATCH v2 1/1] xen/arm: map_domain_page: reuse slots with avail == 0
On Mon, 2013-09-30 at 13:17 +0100, Tim Deegan wrote:> At 13:06 +0100 on 30 Sep (1380546372), Stefano Stabellini wrote: > > If a slot has avail == 0 but still points to the right mfn, reuse it. > > > > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> > > Acked-by: Tim Deegan <tim@xen.org>Likewise, and applied.