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.