From: Roman Gushchin <guro@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, <netdev@vger.kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Shakeel Butt <shakeelb@google.com>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, <kernel-team@fb.com>,
Roman Gushchin <guro@fb.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@suse.com>,
Andrew Morton <akpm@linux-foundation.org>,
Stephen Rothwell <sfr@canb.auug.org.au>
Subject: [PATCH bpf-next v5 03/34] mm: introduce page memcg flags
Date: Thu, 12 Nov 2020 14:15:12 -0800 [thread overview]
Message-ID: <20201112221543.3621014-4-guro@fb.com> (raw)
In-Reply-To: <20201112221543.3621014-1-guro@fb.com>
The lowest bit in page->memcg_data is used to distinguish between struct
memory_cgroup pointer and a pointer to a objcgs array. All checks and
modifications of this bit are open-coded.
Let's formalize it using page memcg flags, defined in enum
page_memcg_data_flags.
Additional flags might be added later.
Link: https://lkml.kernel.org/r/20201027001657.3398190-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
include/linux/memcontrol.h | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c7ac0a5b8989..99a4841d658b 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -343,6 +343,15 @@ struct mem_cgroup {
extern struct mem_cgroup *root_mem_cgroup;
+enum page_memcg_data_flags {
+ /* page->memcg_data is a pointer to an objcgs vector */
+ MEMCG_DATA_OBJCGS = (1UL << 0),
+ /* the next bit after the last actual flag */
+ __NR_MEMCG_DATA_FLAGS = (1UL << 1),
+};
+
+#define MEMCG_DATA_FLAGS_MASK (__NR_MEMCG_DATA_FLAGS - 1)
+
/*
* page_memcg - get the memory cgroup associated with a page
* @page: a pointer to the page struct
@@ -404,13 +413,7 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
*/
unsigned long memcg_data = READ_ONCE(page->memcg_data);
- /*
- * The lowest bit set means that memcg isn't a valid
- * memcg pointer, but a obj_cgroups pointer.
- * In this case the page is shared and doesn't belong
- * to any specific memory cgroup.
- */
- if (memcg_data & 0x1UL)
+ if (memcg_data & MEMCG_DATA_OBJCGS)
return NULL;
return (struct mem_cgroup *)memcg_data;
@@ -429,7 +432,11 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page)
*/
static inline struct obj_cgroup **page_objcgs(struct page *page)
{
- return (struct obj_cgroup **)(READ_ONCE(page->memcg_data) & ~0x1UL);
+ unsigned long memcg_data = READ_ONCE(page->memcg_data);
+
+ VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), page);
+
+ return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
}
/*
@@ -444,10 +451,10 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page)
{
unsigned long memcg_data = READ_ONCE(page->memcg_data);
- if (memcg_data && (memcg_data & 0x1UL))
- return (struct obj_cgroup **)(memcg_data & ~0x1UL);
+ if (!memcg_data || !(memcg_data & MEMCG_DATA_OBJCGS))
+ return NULL;
- return NULL;
+ return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK);
}
/*
@@ -460,7 +467,8 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page)
static inline bool set_page_objcgs(struct page *page,
struct obj_cgroup **objcgs)
{
- return !cmpxchg(&page->memcg_data, 0, (unsigned long)objcgs | 0x1UL);
+ return !cmpxchg(&page->memcg_data, 0, (unsigned long)objcgs |
+ MEMCG_DATA_OBJCGS);
}
#else
static inline struct obj_cgroup **page_objcgs(struct page *page)
--
2.26.2
next prev parent reply other threads:[~2020-11-12 22:26 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-12 22:15 [PATCH bpf-next v5 00/34] bpf: switch to memcg-based memory accounting Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 01/34] mm: memcontrol: use helpers to read page's memcg data Roman Gushchin
2020-11-12 22:56 ` Stephen Rothwell
2020-11-13 0:26 ` Roman Gushchin
2020-11-13 3:04 ` Alexei Starovoitov
2020-11-13 3:18 ` Andrew Morton
2020-11-13 3:25 ` Alexei Starovoitov
2020-11-13 3:40 ` Andrew Morton
2020-11-13 4:08 ` Alexei Starovoitov
2020-11-13 4:01 ` Roman Gushchin
2020-11-13 14:25 ` Shakeel Butt
2020-11-13 17:18 ` Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 02/34] mm: memcontrol/slab: use helpers to access slab page's memcg_data Roman Gushchin
2020-11-12 22:15 ` Roman Gushchin [this message]
2020-11-12 22:15 ` [PATCH bpf-next v5 04/34] mm: convert page kmemcg type to a page memcg flag Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 05/34] bpf: memcg-based memory accounting for bpf progs Roman Gushchin
2020-11-13 17:31 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 06/34] bpf: prepare for memcg-based memory accounting for bpf maps Roman Gushchin
2020-11-13 17:46 ` Song Liu
2020-11-13 19:40 ` Roman Gushchin
2020-11-13 20:48 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 07/34] bpf: " Roman Gushchin
2020-11-13 18:04 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 08/34] bpf: refine memcg-based memory accounting for arraymap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 09/34] bpf: refine memcg-based memory accounting for cpumap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 10/34] bpf: memcg-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 11/34] bpf: refine memcg-based memory accounting for devmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 12/34] bpf: refine memcg-based memory accounting for hashtab maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 13/34] bpf: memcg-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 14/34] bpf: memcg-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 15/34] bpf: memcg-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-13 18:07 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 16/34] bpf: refine memcg-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 17/34] bpf: refine memcg-based memory accounting for xskmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 18/34] bpf: eliminate rlimit-based memory accounting for arraymap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 19/34] bpf: eliminate rlimit-based memory accounting for bpf_struct_ops maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 20/34] bpf: eliminate rlimit-based memory accounting for cpumap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 21/34] bpf: eliminate rlimit-based memory accounting for cgroup storage maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 22/34] bpf: eliminate rlimit-based memory accounting for devmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 23/34] bpf: eliminate rlimit-based memory accounting for hashtab maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 24/34] bpf: eliminate rlimit-based memory accounting for lpm_trie maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 25/34] bpf: eliminate rlimit-based memory accounting for queue_stack_maps maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 26/34] bpf: eliminate rlimit-based memory accounting for reuseport_array maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 27/34] bpf: eliminate rlimit-based memory accounting for bpf ringbuffer Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 28/34] bpf: eliminate rlimit-based memory accounting for sockmap and sockhash maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 29/34] bpf: eliminate rlimit-based memory accounting for stackmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 30/34] bpf: eliminate rlimit-based memory accounting for xskmap maps Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 31/34] bpf: eliminate rlimit-based memory accounting for bpf local storage maps Roman Gushchin
2020-11-13 18:14 ` Song Liu
2020-11-13 19:33 ` Roman Gushchin
2020-11-13 20:53 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 32/34] bpf: eliminate rlimit-based memory accounting infra for bpf maps Roman Gushchin
2020-11-13 18:17 ` Song Liu
2020-11-12 22:15 ` [PATCH bpf-next v5 33/34] bpf: eliminate rlimit-based memory accounting for bpf progs Roman Gushchin
2020-11-12 22:15 ` [PATCH bpf-next v5 34/34] bpf: samples: do not touch RLIMIT_MEMLOCK Roman Gushchin
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