Commit 92855270 authored by Kaitao Cheng's avatar Kaitao Cheng Committed by Linus Torvalds
Browse files

mm/memcontrol.c: cleanup some useless code 

Compound pages handling in mem_cgroup_migrate is more convoluted than
necessary.  The state is duplicated in compound variable and the same
could be achieved by PageTransHuge check which is trivial and
hpage_nr_pages is already PageTransHuge aware.

It is much simpler to just use hpage_nr_pages for nr_pages and replace
the local variable by PageTransHuge check directly

Link: http://lkml.kernel.org/r/20191210160450.3395-1-pilgrimtao@gmail.com


Signed-off-by: default avatarKaitao Cheng <pilgrimtao@gmail.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 10c8d69f

mm/memcontrol.c

+3 −4
Original line number Diff line number Diff line
@@ -6633,7 +6633,6 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) 
{

	struct mem_cgroup *memcg;

	unsigned int nr_pages;

	bool compound;

	unsigned long flags;



	VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
@@ -6655,8 +6654,7 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) 
		return;



	/* Force-charge the new page. The old one will be freed soon */

	compound = PageTransHuge(newpage);

	nr_pages = compound ? hpage_nr_pages(newpage) : 1;

	nr_pages = hpage_nr_pages(newpage);



	page_counter_charge(&memcg->memory, nr_pages);

	if (do_memsw_account())
@@ -6666,7 +6664,8 @@ void mem_cgroup_migrate(struct page *oldpage, struct page *newpage) 
	commit_charge(newpage, memcg, false);



	local_irq_save(flags);

	mem_cgroup_charge_statistics(memcg, newpage, compound, nr_pages);

	mem_cgroup_charge_statistics(memcg, newpage, PageTransHuge(newpage),

			nr_pages);

	memcg_check_events(memcg, newpage);

	local_irq_restore(flags);

}