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Tue, 03 Nov 2026 05:54:14 +0000 X-Mizu-Trace-ID: 4e3eec371c58ba17 X-Migadu-Flow: FLOW_OUT Date: Tue, 3 Nov 2026 13:54:07 +0800 From: Baoquan He To: Ridong Chen Cc: Steven Rostedt , Masami Hiramatsu , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Dave Chinner , Mathieu Desnoyers , Muchun Song , Qi Zheng , David Hildenbrand , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baolin Wang , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, "open list:BPF [MISC]:Keyword:(?:b|_)bpf(?:b|_)" , Ridong Chen Subject: Re: [PATCH v6 6/7] mm/mglru: add lruvec_gen_size() helper Message-ID: References: <20261103025610.3738894-1-ridong.chen@linux.dev> <20261103025610.3738894-7-ridong.chen@linux.dev> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261103025610.3738894-7-ridong.chen@linux.dev> X-Stat-Signature: q85dszkce86zswxcqpbf4spe17n4xsec X-Rspam-User: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: EB4E5100009 X-HE-Tag: 1793685256-666044 X-HE-Meta: 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 4qzjH7A1 qfHjUmk88ywamfPS6Z9Z3JaTIJoYLuYL+zzUAipykowebm5fMC4VGivLLDjEexhI7ocSB6dC3U7/rD37WALSNk7eOUV7/A608u/yXCQSZp4qOOIJ4Fmau/6diggLMeGo0HVsGUwVd5sgICIey5jHwR44urL/kfofp9EWAD4+IL46Yhc77BM5HynicT35o9Ni3tcFP5EZqazBTXunjn7uG8FkucQyFDGgeVP7yT82b7agaXM4sK/+syVPtegXT9EoskzZSI4e0ETsKU/WqM1j4y/YiJIdr1lwo8eeV0k1hTHxi/RwKIdH2AWQK0lSCBJ/JwGOkZBiLx6dVdS/BZ9pDGNp/KoCXU2oHdycSoWrKGR565Pc= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 11/03/26 at 10:56am, Ridong Chen wrote: > From: Ridong Chen > > The number of pages of a given type in a generation is computed by > summing lrugen->nr_pages[gen][type][] over all zones and clamping each > per-zone counter to >= 0, since the counters are updated locklessly and > can transiently go negative. This loop is open-coded in > lruvec_evictable_size() and in the debugfs lru_gen output. > > Add lruvec_gen_size() to compute it from a seq, and convert both users. > Put it in mm/vmscan.h so that the vmscan tracepoints, which include that > header, can use it as well. > An upcoming tracepoint and the MGLRU swappiness rework will also use it. > > No functional change. > > Suggested-by: Barry Song > Signed-off-by: Ridong Chen > --- > mm/vmscan.c | 18 ++++++------------ > mm/vmscan.h | 16 ++++++++++++++++ > 2 files changed, 22 insertions(+), 12 deletions(-) LGTM, Reviewed-by: Baoquan He > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 3054175717ab..1581b73aec56 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4207,18 +4207,15 @@ static void set_initial_priority(struct pglist_data *pgdat, struct scan_control > > static unsigned long lruvec_evictable_size(struct lruvec *lruvec, int swappiness) > { > - int gen, type, zone; > + int type; > unsigned long seq, total = 0; > struct lru_gen_folio *lrugen = &lruvec->lrugen; > DEFINE_MAX_SEQ(lruvec); > DEFINE_MIN_SEQ(lruvec); > > for_each_evictable_type(type, swappiness) { > - for (seq = min_seq[type]; seq <= max_seq; seq++) { > - gen = lru_gen_from_seq(seq); > - for (zone = 0; zone < MAX_NR_ZONES; zone++) > - total += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); > - } > + for (seq = min_seq[type]; seq <= max_seq; seq++) > + total += lruvec_gen_size(lrugen, type, seq); > } > > return total; > @@ -5723,20 +5720,17 @@ static int lru_gen_seq_show(struct seq_file *m, void *v) > seq = 0; > > for (; seq <= max_seq; seq++) { > - int type, zone; > + int type; > int gen = lru_gen_from_seq(seq); > unsigned long birth = READ_ONCE(lruvec->lrugen.timestamps[gen]); > > seq_printf(m, " %10lu %10u", seq, jiffies_to_msecs(jiffies - birth)); > > for (type = 0; type < ANON_AND_FILE; type++) { > - unsigned long size = 0; > char mark = full && seq < min_seq[type] ? 'x' : ' '; > > - for (zone = 0; zone < MAX_NR_ZONES; zone++) > - size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); > - > - seq_printf(m, " %10lu%c", size, mark); > + seq_printf(m, " %10lu%c", > + lruvec_gen_size(lrugen, type, seq), mark); > } > > seq_putc(m, '\n'); > diff --git a/mm/vmscan.h b/mm/vmscan.h > index adb22e80d760..c6b583fc7493 100644 > --- a/mm/vmscan.h > +++ b/mm/vmscan.h > @@ -3,6 +3,7 @@ > #define _MM_VMSCAN_H > > #include > +#include > #include > #include > #include > @@ -115,4 +116,19 @@ struct scan_control { > struct reclaim_state reclaim_state; > }; > > +#ifdef CONFIG_LRU_GEN > +/* The number of pages of @type in the generation @seq, summed over all zones */ > +static inline unsigned long lruvec_gen_size(struct lru_gen_folio *lrugen, > + int type, unsigned long seq) > +{ > + int gen = lru_gen_from_seq(seq); > + unsigned long size = 0; > + > + for (int zone = 0; zone < MAX_NR_ZONES; zone++) > + size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L); > + > + return size; > +} > +#endif /* CONFIG_LRU_GEN */ > + > #endif /* _MM_VMSCAN_H */ > -- > 2.34.1 >