[CRIU] [RFC 3/3] mem: Start using pagemap cache

[Cyrill Gorcunov]

Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
---
 mem.c | 49 ++++++++++++++++++++-----------------------------
 1 file changed, 20 insertions(+), 29 deletions(-)

diff --git a/mem.c b/mem.c
index 2c2717d290d6..a4d22bdf19a3 100644
--- a/mem.c
+++ b/mem.c
@@ -19,6 +19,7 @@
 #include "pstree.h"
 #include "restorer.h"
 #include "files-reg.h"
+#include "pagemap-cache.h"
 
 #include "protobuf.h"
 #include "protobuf/pagemap.pb-c.h"
@@ -105,28 +106,27 @@ static inline bool page_in_parent(u64 pme)
  * the memory contents is present in the pagent image set.
  */
 
-static int generate_iovs(struct vma_area *vma, int pagemap,
-			 struct page_pipe *pp, u64 *map, u64 *off)
+static int generate_iovs(pmc_t *pmc, struct vma_area *vma,
+			 struct page_pipe *pp, u64 *off)
 {
-	unsigned long pfn, nr_to_scan;
+	unsigned long nr_to_scan;
 	unsigned long pages[2] = {};
 	unsigned long vaddr = *off;
-	u64 from, len;
+	u64 pme;
 
-	nr_to_scan = (vma->e->end - vaddr) / PAGE_SIZE;
-	from = vaddr / PAGE_SIZE * sizeof(*map);
-	len = nr_to_scan * sizeof(*map);
-	if (pread(pagemap, map, len, from) != len) {
-		pr_perror("Can't read pagemap file");
-		return -1;
-	}
+	nr_to_scan = PAGEMAP_PFN(vma->e->end - vaddr);
 
 	for ( ; vaddr < vma->e->end; vaddr += PAGE_SIZE) {
 		int ret;
 
-		pfn = (vaddr - vma->e->start) / PAGE_SIZE;
+		pme = pmc_get_pme(pmc, vma, vaddr);
+		if (pme == PAGEMAP_PME_ERR) {
+			pr_err("Failed obtain PME for %p\n", (void *)vaddr);
+			*off = vaddr;
+			return -1;
+		}
 
-		if (!should_dump_page(vma->e, map[pfn]))
+		if (!should_dump_page(vma->e, pme))
 			continue;
 
 		/*
@@ -136,7 +136,7 @@ static int generate_iovs(struct vma_area *vma, int pagemap,
 		 * page. The latter would be checked in page-xfer.
 		 */
 
-		if (page_in_parent(map[pfn])) {
+		if (page_in_parent(pme)) {
 			ret = page_pipe_add_hole(pp, vaddr);
 			pages[0]++;
 		} else {
@@ -236,8 +236,7 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 		struct vm_area_list *vma_area_list,
 		struct page_pipe **pp_ret)
 {
-	u64 *map;
-	int pagemap;
+	pmc_t pmc = PMC_INIT;
 	struct page_pipe *pp;
 	struct vma_area *vma_area;
 	struct page_xfer xfer;
@@ -258,19 +257,14 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 	 * Step 0 -- prepare
 	 */
 
-	map = xmalloc(vma_area_list->longest * sizeof(*map));
-	if (!map)
-		goto out;
-
-	ret = pagemap = open_proc(ctl->pid.real, "pagemap");
-	if (ret < 0)
-		goto out_free;
+	if (pmc_init(&pmc, ctl->pid.real, &vma_area_list->h, vma_area_list->longest))
+		return -1;
 
 	ret = -1;
 	pp = create_page_pipe(vma_area_list->priv_size / 2,
 				pargs_iovs(args), pp_ret == NULL);
 	if (!pp)
-		goto out_close;
+		goto out;
 
 	if (pp_ret == NULL) {
 		ret = open_page_xfer(&xfer, CR_FD_PAGEMAP, ctl->pid.virt);
@@ -288,7 +282,7 @@ static int __parasite_dump_pages_seized(struct parasite_ctl *ctl,
 		if (!privately_dump_vma(vma_area))
 			continue;
 again:
-		ret = generate_iovs(vma_area, pagemap, pp, map, &off);
+		ret = generate_iovs(&pmc, vma_area, pp, &off);
 		if (ret == -EAGAIN) {
 			BUG_ON(pp_ret);
 
@@ -322,11 +316,8 @@ out_xfer:
 out_pp:
 	if (ret || !pp_ret)
 		destroy_page_pipe(pp);
-out_close:
-	close(pagemap);
-out_free:
-	xfree(map);
 out:
+	pmc_fini(&pmc);
 	pr_info("----------------------------------------\n");
 	return ret;
 }
-- 
1.8.3.1