Messages in this thread | | | Date | Mon, 25 Jan 2021 16:17:06 +0000 | From | Matthew Wilcox <> | Subject | Re: [PATCH v16 08/11] secretmem: add memcg accounting |
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On Thu, Jan 21, 2021 at 02:27:20PM +0200, Mike Rapoport wrote: > 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.
I think this is wrong. It fails to account subsequent allocators from the same PMD. If you want to track like this, you need separate pools per memcg.
I think you shouldn't try to track like this; better to just track on a per-page basis. After all, the page allocator doesn't track order-10 pages to the memcg that initially caused them to be split.
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> > Acked-by: Roman Gushchin <guro@fb.com> > Reviewed-by: Shakeel Butt <shakeelb@google.com> > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Christopher Lameter <cl@linux.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Elena Reshetova <elena.reshetova@intel.com> > Cc: Hagen Paul Pfeifer <hagen@jauu.net> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: James Bottomley <jejb@linux.ibm.com> > Cc: "Kirill A. Shutemov" <kirill@shutemov.name> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Matthew Wilcox <willy@infradead.org> > Cc: Michael Kerrisk <mtk.manpages@gmail.com> > Cc: Palmer Dabbelt <palmer@dabbelt.com> > Cc: Palmer Dabbelt <palmerdabbelt@google.com> > Cc: Paul Walmsley <paul.walmsley@sifive.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> > Cc: Shuah Khan <shuah@kernel.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Tycho Andersen <tycho@tycho.ws> > Cc: Will Deacon <will@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 >
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