[PATCH v11 6/9] secretmem: add memcg accounting

Mike Rapoport
2020-11-24T09:27:47Z

Account memory consumed by secretmem to memcg. The accounting is updated
when the memory is actually allocated and freed.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Roman Gushchin <guro@fb.com>
---
mm/filemap.c | 3 ++-
mm/secretmem.c | 36 +++++++++++++++++++++++++++++++++++-
2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 249cf489f5df..cf7f1dc9f4b8 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -42,6 +42,7 @@
#include <linux/psi.h>
#include <linux/ramfs.h>
#include <linux/page_idle.h>
+#include <linux/secretmem.h>
#include "internal.h"

#define CREATE_TRACE_POINTS
@@ -844,7 +845,7 @@ static noinline int __add_to_page_cache_locked(struct page *page,
page->mapping = mapping;
page->index = offset;

- if (!huge) {
+ if (!huge && !page_is_secretmem(page)) {
error = mem_cgroup_charge(page, current->mm, gfp);
if (error)
goto error;
diff --git a/mm/secretmem.c b/mm/secretmem.c
index 52a900a135a5..eb6628390444 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -18,6 +18,7 @@
#include <linux/memblock.h>
#include <linux/pseudo_fs.h>
#include <linux/secretmem.h>
+#include <linux/memcontrol.h>
#include <linux/set_memory.h>
#include <linux/sched/signal.h>

@@ -44,6 +45,32 @@ struct secretmem_ctx {

static struct cma *secretmem_cma;

+static int secretmem_account_pages(struct page *page, gfp_t gfp, int order)
+{
+ int err;
+
+ err = memcg_kmem_charge_page(page, gfp, order);
+ if (err)
+ return err;
+
+ /*
+ * seceremem caches are unreclaimable kernel allocations, so treat
+ * them as unreclaimable slab memory for VM statistics purposes
+ */
+ mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B,
+ PAGE_SIZE << order);
+
+ return 0;
+}
+
+static void secretmem_unaccount_pages(struct page *page, int order)
+{
+
+ mod_node_page_state(page_pgdat(page), NR_SLAB_UNRECLAIMABLE_B,
+ -PAGE_SIZE << order);
+ memcg_kmem_uncharge_page(page, order);
+}
+
static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp)
{
unsigned long nr_pages = (1 << PMD_PAGE_ORDER);
@@ -56,10 +83,14 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp)
if (!page)
return -ENOMEM;

- err = set_direct_map_invalid_noflush(page, nr_pages);
+ err = secretmem_account_pages(page, gfp, PMD_PAGE_ORDER);
if (err)
goto err_cma_release;

+ err = set_direct_map_invalid_noflush(page, nr_pages);
+ if (err)
+ goto err_memcg_uncharge;
+
addr = (unsigned long)page_address(page);
err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE);
if (err)
@@ -76,6 +107,8 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp)
* won't fail
*/
set_direct_map_default_noflush(page, nr_pages);
+err_memcg_uncharge:
+ secretmem_unaccount_pages(page, PMD_PAGE_ORDER);
err_cma_release:
cma_release(secretmem_cma, page, nr_pages);
return err;
@@ -302,6 +335,7 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool,
int i;

set_direct_map_default_noflush(page, nr_pages);
+ secretmem_unaccount_pages(page, PMD_PAGE_ORDER);

for (i = 0; i < nr_pages; i++)
clear_highpage(page + i);
--
2.28.0