Mailing List Archive

# HG changeset patch
# User Olaf Hering <olaf@aepfle.de>
# Date 1321804965 -3600
# Node ID 827fcaf0d610dd0c54d3f1f305b2b8f12bd4240a
# Parent 303d1521463bda6431cc0001d8755dd681e67a0d
xenpaging: use guests tot_pages as working target

This change reverses the task of xenpaging. Before this change a fixed number
of pages was paged out. With this change the guest will not have access to
more than the given number of pages at the same time.

Signed-off-by: Olaf Hering <olaf@aepfle.de>

diff -r 303d1521463b -r 827fcaf0d610 tools/xenpaging/policy_default.c
--- a/tools/xenpaging/policy_default.c
+++ b/tools/xenpaging/policy_default.c
@@ -71,7 +71,6 @@ int policy_init(xenpaging_t *paging)

/* Start in the middle to avoid paging during BIOS startup */
current_gfn = max_pages / 2;
- current_gfn -= paging->num_pages / 2;

rc = 0;
out:
diff -r 303d1521463b -r 827fcaf0d610 tools/xenpaging/xenpaging.c
--- a/tools/xenpaging/xenpaging.c
+++ b/tools/xenpaging/xenpaging.c
@@ -136,6 +136,21 @@ err:
return rc;
}

+static int xenpaging_get_tot_pages(xenpaging_t *paging)
+{
+ xc_interface *xch = paging->xc_handle;
+ xc_domaininfo_t domain_info;
+ int rc;
+
+ rc = xc_domain_getinfolist(xch, paging->mem_event.domain_id, 1, &domain_info);
+ if ( rc != 1 )
+ {
+ PERROR("Error getting domain info");
+ return -1;
+ }
+ return domain_info.tot_pages;
+}
+
static void *init_page(void)
{
void *buffer;
@@ -161,7 +176,7 @@ static void *init_page(void)
return NULL;
}

-static xenpaging_t *xenpaging_init(domid_t domain_id, int num_pages)
+static xenpaging_t *xenpaging_init(domid_t domain_id, int target_tot_pages)
{
xenpaging_t *paging;
xc_domaininfo_t domain_info;
@@ -296,12 +311,7 @@ static xenpaging_t *xenpaging_init(domid
}
DPRINTF("max_pages = %d\n", paging->max_pages);

- if ( num_pages < 0 || num_pages > paging->max_pages )
- {
- num_pages = paging->max_pages;
- DPRINTF("setting num_pages to %d\n", num_pages);
- }
- paging->num_pages = num_pages;
+ paging->target_tot_pages = target_tot_pages;

/* Initialise policy */
rc = policy_init(paging);
@@ -648,7 +658,9 @@ int main(int argc, char *argv[])
xenpaging_victim_t *victims;
mem_event_request_t req;
mem_event_response_t rsp;
+ int num, prev_num = 0;
int i;
+ int tot_pages;
int rc = -1;
int rc1;
xc_interface *xch;
@@ -659,7 +671,7 @@ int main(int argc, char *argv[])

if ( argc != 3 )
{
- fprintf(stderr, "Usage: %s <domain_id> <num_pages>\n", argv[0]);
+ fprintf(stderr, "Usage: %s <domain_id> <tot_pages>\n", argv[0]);
return -1;
}

@@ -672,7 +684,7 @@ int main(int argc, char *argv[])
}
xch = paging->xc_handle;

- DPRINTF("starting %s %u %d\n", argv[0], paging->mem_event.domain_id, paging->num_pages);
+ DPRINTF("starting %s %u %d\n", argv[0], paging->mem_event.domain_id, paging->target_tot_pages);

/* Open file */
sprintf(filename, "page_cache_%u", paging->mem_event.domain_id);
@@ -704,9 +716,6 @@ int main(int argc, char *argv[])
/* listen for page-in events to stop pager */
create_page_in_thread(paging);

- i = evict_pages(paging, fd, victims, paging->num_pages);
- DPRINTF("%d pages evicted. Done.\n", i);
-
/* Swap pages in and out */
while ( 1 )
{
@@ -771,12 +780,8 @@ int main(int argc, char *argv[])
goto out;
}

- /* Evict a new page to replace the one we just paged in,
- * or clear this pagefile slot on exit */
- if ( interrupted )
- victims[i].gfn = INVALID_MFN;
- else
- evict_victim(paging, &victims[i], fd, i);
+ /* Clear this pagefile slot */
+ victims[i].gfn = INVALID_MFN;
}
else
{
@@ -823,6 +828,43 @@ int main(int argc, char *argv[])
if ( interrupted )
break;

+ /* Check if the target has been reached already */
+ tot_pages = xenpaging_get_tot_pages(paging);
+ if ( tot_pages < 0 )
+ goto out;
+
+ /* Resume all pages if paging is disabled or no target was set */
+ if ( paging->target_tot_pages == 0 )
+ {
+ if ( paging->num_paged_out )
+ resume_pages(paging, paging->num_paged_out);
+ }
+ /* Evict more pages if target not reached */
+ else if ( tot_pages > paging->target_tot_pages )
+ {
+ num = tot_pages - paging->target_tot_pages;
+ if ( num != prev_num )
+ {
+ DPRINTF("Need to evict %d pages to reach %d target_tot_pages\n", num, paging->target_tot_pages);
+ prev_num = num;
+ }
+ /* Limit the number of evicts to be able to process page-in requests */
+ if ( num > 42 )
+ num = 42;
+ evict_pages(paging, fd, victims, num);
+ }
+ /* Resume some pages if target not reached */
+ else if ( tot_pages < paging->target_tot_pages && paging->num_paged_out )
+ {
+ num = paging->target_tot_pages - tot_pages;
+ if ( num != prev_num )
+ {
+ DPRINTF("Need to resume %d pages to reach %d target_tot_pages\n", num, paging->target_tot_pages);
+ prev_num = num;
+ }
+ resume_pages(paging, num);
+ }
+
}
DPRINTF("xenpaging got signal %d\n", interrupted);

diff -r 303d1521463b -r 827fcaf0d610 tools/xenpaging/xenpaging.h
--- a/tools/xenpaging/xenpaging.h
+++ b/tools/xenpaging/xenpaging.h
@@ -50,7 +50,7 @@ typedef struct xenpaging {
/* number of pages for which data structures were allocated */
int max_pages;
int num_paged_out;
- int num_pages;
+ int target_tot_pages;
int policy_mru_size;
unsigned long pagein_queue[XENPAGING_PAGEIN_QUEUE_SIZE];
} xenpaging_t;

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