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From: Qi Zheng In-Reply-To: <20260326143736.12d22e38@pumpkin> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Queue-Id: C5A9E1C0003 X-Stat-Signature: ghmri17f43a454smy3sxfqnuzciknbzx X-Rspamd-Server: rspam06 X-HE-Tag: 1774579103-819645 X-HE-Meta: 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 0VVDmqUa QnPersdpk5TDU12D+dAbhykBLInr7bXY+oCy1vvM3c0+lYMVSh89DFCinOHGj3V7VsAn6OmkvwK85EepiX1jtrIJTC31NOEf4HrPlvjVGLwdRedpTfcD+GcI4Z4PT8MnjRCXQMdM7cMbMIfiZp5T9vA3/y1K4JY3SVRN5Ho1WOxsDEwdT0nrMSAJYZpkjzCMNb//tWl61tur1Tx/F2DJ8jCNwZw6GGgycM+m5isxH+FmmfYbpnb2e00KvURY0ghb/0sfr8BwdBtEqCVYeVjuvJ2rCmmzn+Q1b9iVI9JsqUWn0t2CLV3b35abYa7ThyuQGdbX04mBh8ODZA28DVofAmGzp0hedQBcr1m7mQTleLStKBu0QvUyAPdgO5sS6neoKSRKA0EOENgp6fRVANGQmNONs1Q== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 3/26/26 10:37 PM, David Laight wrote: > On Thu, 26 Mar 2026 09:19:29 +0000 > "Lorenzo Stoakes (Oracle)" wrote: > >> On Wed, Mar 25, 2026 at 10:13:23PM +0800, Qi Zheng wrote: >>> From: Qi Zheng >>> >>> The __mod_memcg_state() and __mod_memcg_lruvec_state() functions are also >>> used to reparent non-hierarchical stats. In this scenario, the values >>> passed to them are accumulated statistics that might be extremely large >>> and exceed the upper limit of a 32-bit integer. >>> >>> Change the val parameter type from int to long in these functions and >>> their corresponding tracepoints (memcg_rstat_stats) to prevent potential >>> overflow issues. > > Won't that are be true on 32bit systems? > Which means the underlying values need to be u64 not long. On a 32-bit system, such a large number of values ​​should not accumulate. Furthermore, changing it to u64/s64 would mean modifying memcg_vmstats_percpu->state and lruvec_stats_percpu->state, which involves significant changes, so I think it might be unnecessary. Thanks, Qi > > David > >>> >>> Signed-off-by: Qi Zheng >> >> LGTM, so: >> >> Reviewed-by: Lorenzo Stoakes (Oracle) >> >>> --- >>> include/trace/events/memcg.h | 10 +++++----- >>> mm/memcontrol.c | 8 ++++---- >>> 2 files changed, 9 insertions(+), 9 deletions(-) >>> >>> diff --git a/include/trace/events/memcg.h b/include/trace/events/memcg.h >>> index dfe2f51019b4c..51b62c5931fc2 100644 >>> --- a/include/trace/events/memcg.h >>> +++ b/include/trace/events/memcg.h >>> @@ -11,14 +11,14 @@ >>> >>> DECLARE_EVENT_CLASS(memcg_rstat_stats, >>> >>> - TP_PROTO(struct mem_cgroup *memcg, int item, int val), >>> + TP_PROTO(struct mem_cgroup *memcg, int item, long val), >>> >>> TP_ARGS(memcg, item, val), >>> >>> TP_STRUCT__entry( >>> __field(u64, id) >>> __field(int, item) >>> - __field(int, val) >>> + __field(long, val) >>> ), >>> >>> TP_fast_assign( >>> @@ -27,20 +27,20 @@ DECLARE_EVENT_CLASS(memcg_rstat_stats, >>> __entry->val = val; >>> ), >>> >>> - TP_printk("memcg_id=%llu item=%d val=%d", >>> + TP_printk("memcg_id=%llu item=%d val=%ld", >>> __entry->id, __entry->item, __entry->val) >>> ); >>> >>> DEFINE_EVENT(memcg_rstat_stats, mod_memcg_state, >>> >>> - TP_PROTO(struct mem_cgroup *memcg, int item, int val), >>> + TP_PROTO(struct mem_cgroup *memcg, int item, long val), >>> >>> TP_ARGS(memcg, item, val) >>> ); >>> >>> DEFINE_EVENT(memcg_rstat_stats, mod_memcg_lruvec_state, >>> >>> - TP_PROTO(struct mem_cgroup *memcg, int item, int val), >>> + TP_PROTO(struct mem_cgroup *memcg, int item, long val), >>> >>> TP_ARGS(memcg, item, val) >>> ); >>> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >>> index 7fb9cbc10dfbb..4a78550f6174e 100644 >>> --- a/mm/memcontrol.c >>> +++ b/mm/memcontrol.c >>> @@ -527,7 +527,7 @@ unsigned long lruvec_page_state_local(struct lruvec *lruvec, >>> >>> #ifdef CONFIG_MEMCG_V1 >>> static void __mod_memcg_lruvec_state(struct mem_cgroup_per_node *pn, >>> - enum node_stat_item idx, int val); >>> + enum node_stat_item idx, long val); >>> >>> void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg, >>> struct mem_cgroup *parent, int idx) >>> @@ -784,7 +784,7 @@ static int memcg_page_state_unit(int item); >>> * Normalize the value passed into memcg_rstat_updated() to be in pages. Round >>> * up non-zero sub-page updates to 1 page as zero page updates are ignored. >>> */ >>> -static int memcg_state_val_in_pages(int idx, int val) >>> +static long memcg_state_val_in_pages(int idx, long val) >>> { >>> int unit = memcg_page_state_unit(idx); >>> >>> @@ -831,7 +831,7 @@ static inline void get_non_dying_memcg_end(void) >>> #endif >>> >>> static void __mod_memcg_state(struct mem_cgroup *memcg, >>> - enum memcg_stat_item idx, int val) >>> + enum memcg_stat_item idx, long val) >>> { >>> int i = memcg_stats_index(idx); >>> int cpu; >>> @@ -896,7 +896,7 @@ void reparent_memcg_state_local(struct mem_cgroup *memcg, >>> #endif >>> >>> static void __mod_memcg_lruvec_state(struct mem_cgroup_per_node *pn, >>> - enum node_stat_item idx, int val) >>> + enum node_stat_item idx, long val) >>> { >>> struct mem_cgroup *memcg = pn->memcg; >>> int i = memcg_stats_index(idx); >>> -- >>> 2.20.1 >>> >> >