search for: mark_free_pages_bitmap

...changed, 46 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 7da61ad..3ad8b10 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4523,6 +4523,52 @@ unsigned long get_max_pfn(void) > } > EXPORT_SYMBOL(get_max_pfn); > > +static void mark_free_pages_bitmap(struct zone *zone, unsigned long start_pfn, > + unsigned long end_pfn, unsigned long *bitmap, unsigned long len) > +{ > + unsigned long pfn, flags, page_num; > + unsigned int order, t; > + struct list_head *curr; > + > + if (zone_is_empty(zone)) > + return; > + end_pfn =...

...changed, 46 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 7da61ad..3ad8b10 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4523,6 +4523,52 @@ unsigned long get_max_pfn(void) > } > EXPORT_SYMBOL(get_max_pfn); > > +static void mark_free_pages_bitmap(struct zone *zone, unsigned long start_pfn, > + unsigned long end_pfn, unsigned long *bitmap, unsigned long len) > +{ > + unsigned long pfn, flags, page_num; > + unsigned int order, t; > + struct list_head *curr; > + > + if (zone_is_empty(zone)) > + return; > + end_pfn =...

...+++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7da61ad..3ad8b10 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4523,6 +4523,52 @@ unsigned long get_max_pfn(void) } EXPORT_SYMBOL(get_max_pfn); +static void mark_free_pages_bitmap(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn, unsigned long *bitmap, unsigned long len) +{ + unsigned long pfn, flags, page_num; + unsigned int order, t; + struct list_head *curr; + + if (zone_is_empty(zone)) + return; + end_pfn = min(start_pfn + len, end_pfn); + spin_lock_i...

...;free_page_bitmap', and then the driver will send the content of 'free_page_bitmap' back to QEMU. That all the new interface does and there are no ' alloc_page' related affairs, so it's faster. Some code snippet: ---------------------------------------------- +static void mark_free_pages_bitmap(struct zone *zone, + unsigned long *free_page_bitmap, unsigned long pfn_gap) { + unsigned long pfn, flags, i; + unsigned int order, t; + struct list_head *curr; + + if (zone_is_empty(zone)) + return; + + spin_lock_irqsave(&zone->lock, flags); + + for_each_migratetype_order(order, t) { +...

...;free_page_bitmap', and then the driver will send the content of 'free_page_bitmap' back to QEMU. That all the new interface does and there are no ' alloc_page' related affairs, so it's faster. Some code snippet: ---------------------------------------------- +static void mark_free_pages_bitmap(struct zone *zone, + unsigned long *free_page_bitmap, unsigned long pfn_gap) { + unsigned long pfn, flags, i; + unsigned int order, t; + struct list_head *curr; + + if (zone_is_empty(zone)) + return; + + spin_lock_irqsave(&zone->lock, flags); + + for_each_migratetype_order(order, t) { +...

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

The current QEMU live migration implementation mark the all the guest's RAM pages as dirtied in the ram bulk stage, all these pages will be processed and that takes quit a lot of CPU cycles. >From guest's point of view, it doesn't care about the content in free pages. We can make use of this fact and skip processing the free pages in the ram bulk stage, it can save a lot CPU cycles

...e driver will send the content > of 'free_page_bitmap' back to QEMU. That all the new interface does and > there are no ' alloc_page' related affairs, so it's faster. > > > Some code snippet: > ---------------------------------------------- > +static void mark_free_pages_bitmap(struct zone *zone, > + unsigned long *free_page_bitmap, unsigned long pfn_gap) { > + unsigned long pfn, flags, i; > + unsigned int order, t; > + struct list_head *curr; > + > + if (zone_is_empty(zone)) > + return; > + > + spin_lock_irqsave(&zone->lock, flags); &...

> On Fri, Mar 04, 2016 at 09:12:12AM +0000, Li, Liang Z wrote: > > > Although I wonder which is cheaper; that would be fairly expensive > > > for the guest wouldn't it? And you'd somehow have to kick the guest > > > before migration to do the ballooning - and how long would you wait for > it to finish? > > > > About 5 seconds for an 8G guest,

> On Fri, Mar 04, 2016 at 09:12:12AM +0000, Li, Liang Z wrote: > > > Although I wonder which is cheaper; that would be fairly expensive > > > for the guest wouldn't it? And you'd somehow have to kick the guest > > > before migration to do the ballooning - and how long would you wait for > it to finish? > > > > About 5 seconds for an 8G guest,

This patchset is for kernel and contains two parts of change to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by

This patchset is for kernel and contains two parts of change to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by

This patch set contains two parts of changes to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by about 85%.

This patch set contains two parts of changes to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by about 85%.