On Thu, 9 Jul 2015, Julien Grall wrote:
> Only use the first 4KB of the page to store the events channel info. It
> means that we will wast 60KB every time we allocate page for:
^ waste
> * control block: a page is allocating per CPU
> * event array: a page is allocating everytime we need to expand it
>
> I think we can reduce the memory waste for the 2 areas by:
>
> * control block: sharing between multiple vCPUs. Although it will
> require some bookkeeping in order to not free the page when the CPU
> goes offline and the other CPUs sharing the page still there
>
> * event array: always extend the array event by 64K (i.e 16 4K
> chunk). That would require more care when we fail to expand the
> event channel.
But this is not implemented in this series, right?
> Signed-off-by: Julien Grall <julien.gr...@citrix.com>
> Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
> Cc: Boris Ostrovsky <boris.ostrov...@oracle.com>
> Cc: David Vrabel <david.vra...@citrix.com>
> ---
> drivers/xen/events/events_base.c | 2 +-
> drivers/xen/events/events_fifo.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/xen/events/events_base.c
> b/drivers/xen/events/events_base.c
> index 96093ae..858d2f6 100644
> --- a/drivers/xen/events/events_base.c
> +++ b/drivers/xen/events/events_base.c
> @@ -40,11 +40,11 @@
> #include <asm/idle.h>
> #include <asm/io_apic.h>
> #include <asm/xen/pci.h>
> -#include <xen/page.h>
> #endif
> #include <asm/sync_bitops.h>
> #include <asm/xen/hypercall.h>
> #include <asm/xen/hypervisor.h>
> +#include <xen/page.h>
>
> #include <xen/xen.h>
> #include <xen/hvm.h>
Spurious change?
> diff --git a/drivers/xen/events/events_fifo.c
> b/drivers/xen/events/events_fifo.c
> index ed673e1..d53c297 100644
> --- a/drivers/xen/events/events_fifo.c
> +++ b/drivers/xen/events/events_fifo.c
> @@ -54,7 +54,7 @@
>
> #include "events_internal.h"
>
> -#define EVENT_WORDS_PER_PAGE (PAGE_SIZE / sizeof(event_word_t))
> +#define EVENT_WORDS_PER_PAGE (XEN_PAGE_SIZE / sizeof(event_word_t))
> #define MAX_EVENT_ARRAY_PAGES (EVTCHN_FIFO_NR_CHANNELS /
> EVENT_WORDS_PER_PAGE)
>
> struct evtchn_fifo_queue {
> --
> 2.1.4
>
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