Re: [PATCH v8 6/9] secretmem: add memcg accounting

вт, 10 нояб. 2020 г. в 07:16, Mike Rapoport rppt@kernel.org:

From: Mike Rapoport rppt@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 rppt@linux.ibm.com

mm/filemap.c | 2 +- mm/secretmem.c | 42 +++++++++++++++++++++++++++++++++++++++++- 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c index 249cf489f5df..11387a077373 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -844,7 +844,7 @@ static noinline int __add_to_page_cache_locked(struct page *page, page->mapping = mapping; page->index = offset;

•   if (!huge) {
  

•   if (!huge && !page->memcg_data) {
            error = mem_cgroup_charge(page, current->mm, gfp);
            if (error)
                    goto error;
  

diff --git a/mm/secretmem.c b/mm/secretmem.c index 1aa2b7cffe0d..1eb7667016fa 100644 --- a/mm/secretmem.c +++ b/mm/secretmem.c @@ -17,6 +17,7 @@ #include <linux/syscalls.h> #include <linux/memblock.h> #include <linux/pseudo_fs.h> +#include <linux/memcontrol.h> #include <linux/set_memory.h> #include <linux/sched/signal.h>

@@ -49,6 +50,38 @@ struct secretmem_ctx {

static struct cma *secretmem_cma;

Hi Mike!

+static int secretmem_memcg_charge(struct page *page, gfp_t gfp, int order) +{

•   unsigned long nr_pages = (1 << order);
  

•   int i, err;
  

•   err = memcg_kmem_charge_page(page, gfp, order);
  

•   if (err)
  

•           return err;
  

•   for (i = 1; i < nr_pages; i++) {
  

•           struct page *p = page + i;
  

•           p->memcg_data = page->memcg_data;
  

•   }
  

Hm, it looks very strange to me. Why do we need to copy memcg_data? What about css reference counting?

And what about statistics?

I'm sorry for being late.

Thank you!

•   return 0;
  

+}

+static void secretmem_memcg_uncharge(struct page *page, int order) +{

•   unsigned long nr_pages = (1 << order);
  

•   int i;
  

•   for (i = 1; i < nr_pages; i++) {
  

•           struct page *p = page + i;
  

•           p->memcg_data = 0;
  

•   }
  

•   memcg_kmem_uncharge_page(page, PMD_PAGE_ORDER);
  

+}

static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp) { unsigned long nr_pages = (1 << PMD_PAGE_ORDER); @@ -61,10 +94,14 @@ 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_memcg_charge(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)
  

@@ -81,6 +118,8 @@ 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_memcg_uncharge(page, PMD_PAGE_ORDER);
  

err_cma_release: cma_release(secretmem_cma, page, nr_pages); return err; @@ -310,6 +349,7 @@ static void secretmem_cleanup_chunk(struct gen_pool *pool, int i;

    set_direct_map_default_noflush(page, nr_pages);

•   secretmem_memcg_uncharge(page, PMD_PAGE_ORDER);
  
    for (i = 0; i < nr_pages; i++)
            clear_highpage(page + i);
  

-- 2.28.0