11:01 a.m.
Hi Oliver,
On Fri, Mar 19, 2021 at 08:51:38PM +0800, Oliver Sang wrote:
Hi Hike,
On Fri, Mar 12, 2021 at 06:56:01AM +0200, Mike Rapoport wrote:
> Hello,
>
> On Wed, Mar 10, 2021 at 09:54:26AM +0800, kernel test robot wrote:
> >
> > Greeting,
> >
> > FYI, we noticed a -4.2% regression of will-it-scale.per_thread_ops due to
commit:
> >
> >
> > commit: 81a779a1a49c8644fd8dc994815a9aa379d10825 ("mm: introduce
memfd_secret system call to create "secret" memory areas")
> > https://git.kernel.org/cgit/linux/kernel/git/rppt/linux.git memfd-secret/v18
> >
> >
> > in testcase: will-it-scale
> > on test machine: 192 threads Intel(R) Xeon(R) Platinum 9242 CPU @ 2.30GHz with
192G memory
> > with following parameters:
> >
> > nr_task: 100%
> > mode: thread
> > test: futex1
> > cpufreq_governor: performance
> > ucode: 0x5003006
> >
> > test-description: Will It Scale takes a testcase and runs it from 1 through to
n parallel copies to see if the testcase will scale. It builds both a process and threads
based test in order to see any differences between the two.
> > test-url: https://github.com/antonblanchard/will-it-scale
> >
> >
> >
> > If you fix the issue, kindly add following tag
> > Reported-by: kernel test robot <oliver.sang(a)intel.com>
>
> Can you please test the following patch on top of commit: 81a779a1a49c
> ("mm: introduce memfd_secret system call to create "secret" memory
areas")
> to see if it performs better:
it performs a little better but still has -3.7% regression:
* e9be99d574c74 (linux-devel/fixup-81a779a1a49c) fix-81a779a1a49c-perf
* 81a779a1a49c8 mm: introduce memfd_secret system call to create "secret"
memory areas
* 043463bfe80b8 set_memory: allow querying whether set_direct_map_*() is actually enabled
Can you please retest with the below patch instead of the previous one:
diff --git a/include/linux/secretmem.h b/include/linux/secretmem.h
index 907a6734059c..6debaadb245d 100644
--- a/include/linux/secretmem.h
+++ b/include/linux/secretmem.h
@@ -4,8 +4,26 @@
#ifdef CONFIG_SECRETMEM
+extern const struct address_space_operations secretmem_aops;
+
+static inline bool page_is_secretmem(struct page *page)
+{
+ page = compound_head(page);
+
+ /*
+ * partially open code page_mapping() to avoid calling it on fast
+ * path in get_user_pages_fast()
+ */
+ if (PageMappingFlags(page) || PageSlab(page) || PageSwapCache(page))
+ return false;
+
+ if (!page->mapping)
+ return false;
+
+ return page->mapping->a_ops == &secretmem_aops;
+}
+
bool vma_is_secretmem(struct vm_area_struct *vma);
-bool page_is_secretmem(struct page *page);
bool secretmem_active(void);
#else
diff --git a/mm/secretmem.c b/mm/secretmem.c
index f2ae3f32a193..cfdb6d9a213d 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -151,22 +151,12 @@ static void secretmem_freepage(struct page *page)
clear_highpage(page);
}
-static const struct address_space_operations secretmem_aops = {
+const struct address_space_operations secretmem_aops = {
.freepage = secretmem_freepage,
.migratepage = secretmem_migratepage,
.isolate_page = secretmem_isolate_page,
};
-bool page_is_secretmem(struct page *page)
-{
- struct address_space *mapping = page_mapping(page);
-
- if (!mapping)
- return false;
-
- return mapping->a_ops == &secretmem_aops;
-}
-
static struct vfsmount *secretmem_mnt;
static struct file *secretmem_file_create(unsigned long flags)
--
Sincerely yours,
Mike.