[PATCH v16 08/11] secretmem: add memcg accounting

[Mike Rapoport]

From: Mike Rapoport <r...@linux.ibm.com>

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

Signed-off-by: Mike Rapoport <r...@linux.ibm.com>
Acked-by: Roman Gushchin <g...@fb.com>
Reviewed-by: Shakeel Butt <shake...@google.com>
Cc: Alexander Viro <v...@zeniv.linux.org.uk>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Arnd Bergmann <a...@arndb.de>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Catalin Marinas <catalin.mari...@arm.com>
Cc: Christopher Lameter <c...@linux.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: David Hildenbrand <da...@redhat.com>
Cc: Elena Reshetova <elena.reshet...@intel.com>
Cc: Hagen Paul Pfeifer <ha...@jauu.net>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: James Bottomley <j...@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kir...@shutemov.name>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Matthew Wilcox <wi...@infradead.org>
Cc: Michael Kerrisk <mtk.manpa...@gmail.com>
Cc: Palmer Dabbelt <pal...@dabbelt.com>
Cc: Palmer Dabbelt <palmerdabb...@google.com>
Cc: Paul Walmsley <paul.walms...@sifive.com>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Rick Edgecombe <rick.p.edgeco...@intel.com>
Cc: Shuah Khan <sh...@kernel.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Tycho Andersen <ty...@tycho.ws>
Cc: Will Deacon <w...@kernel.org>
---
 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 2d0c6721879d..bb28dd6d9e22 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
@@ -839,7 +840,7 @@ 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 469211c7cc3a..05026460e2ee 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_lruvec_page_state(page, NR_SLAB_UNRECLAIMABLE_B,
+                             PAGE_SIZE << order);
+
+       return 0;
+}
+
+static void secretmem_unaccount_pages(struct page *page, int order)
+{
+
+       mod_lruvec_page_state(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);
@@ -56,6 +83,10 @@ static int secretmem_pool_increase(struct secretmem_ctx 
*ctx, gfp_t gfp)
        if (!page)
                return -ENOMEM;
 
+       err = secretmem_account_pages(page, gfp, PMD_PAGE_ORDER);
+       if (err)
+               goto err_cma_release;
+
        /*
         * clear the data left from the prevoius user before dropping the
         * pages from the direct map
@@ -65,7 +96,7 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, 
gfp_t gfp)
 
        err = set_direct_map_invalid_noflush(page, nr_pages);
        if (err)
-               goto err_cma_release;
+               goto err_memcg_uncharge;
 
        addr = (unsigned long)page_address(page);
        err = gen_pool_add(pool, addr, PMD_SIZE, NUMA_NO_NODE);
@@ -83,6 +114,8 @@ 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;
@@ -314,6 +347,7 @@ 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