From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-37.mta0.migadu.com [91.218.175.37]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1001845516B for ; Mon, 19 Oct 2026 04:24:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.37 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792383853; cv=none; b=hRctXhd/EqYqeDcIMDM37zXVhwKdnW3qCbXVkAm7PPaOes508xWBm1Mo3ibcSjxg3V8VdsaT9OlDVcs/UQW/2gkP0VBd5CtR5CiIATAaSO9F1BZcNEhFtJSpKtE3MGHnTDAq4wfxCqd9pX+pG7ftHIV/llqF7UErDROOGtDTL8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792383853; c=relaxed/simple; bh=sJuXFmGJeYUYsmp3M6RZmn5KdaBGmBz41TFuVzBcTJY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=BBfIckRhcC3zaxpT3F0PVrsrzNCM66S5YNXKeWeG+YYJVzLU8ACM8x0bfk5MIAc/+9+9FmLa8GTDC4cw7NYrncYRaMo5D/EsJIhblf85x+ax0Ovtp7VVdBY3XPqQmGsIvXRX2YBbjAPZcLJx5Xlc0s8rpuR7gUYSiXGvKgJRAQo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=tltVn2i+; arc=none smtp.client-ip=91.218.175.37 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="tltVn2i+" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=sJuXFmGJeYUYsmp3M6RZmn5KdaBGmBz41TFuVzBcTJY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1792383845; v=1; x=1792988645; b=tltVn2i+pxNA/b6kxY8IwLND9bpDflqZGrbOdphRF+68K5UHyYCeotOfs38EmhpBVUN61piS 6tnWVojHtA2MtH3tjSyuXVjDrF2htx40KCXgsWsnwQlNz/z8g2kUqjpOOmrdgDmnlGpSrLWoIer 3WTnOU0TxKx94QCPTwDVwq5o= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 84520b29f8bc6005; Mon, 19 Oct 2026 04:24:05 +0000 X-Mizu-Trace-ID: 84520b29f8bc6005 X-Migadu-Flow: FLOW_OUT From: Ridong Chen To: Steven Rostedt , Masami Hiramatsu , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Dave Chinner Cc: Mathieu Desnoyers , Muchun Song , Qi Zheng , David Hildenbrand , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, bpf@vger.kernel.org, Ridong Chen , Ridong Chen Subject: [PATCH v4 8/9] mm/mglru: add tracepoint for scan_folios() Date: Mon, 19 Oct 2026 12:23:07 +0800 Message-Id: <20261019042308.2372396-3-ridong.chen@linux.dev> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20261019034426.2354049-1-ridong.chen@linux.dev> References: <20261019034426.2354049-1-ridong.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ridong Chen MGLRU's scan_folios() emits the classic-LRU tracepoint trace_mm_vmscan_lru_isolate(), which predates MGLRU. It reports the scan/isolate counts and the LRU type, but carries no generation or memcg context, so a trace of an MGLRU run cannot tell which memcg a given scan belongs to, nor how far reclaim has progressed through the generations. Add mm_mglru_scan_folios next to it, reporting the same counters plus nr_sorted (folios moved to a younger generation by sort_folio()) and the context the classic tracepoint lacks: the node id and memcg id of the lruvec, and the max_seq, tier and min_seq of the type being scanned. Now that struct scan_control is visible to the trace header, pass sc, lruvec, type and tier straight in and derive everything else in TP_fast_assign(), so nothing is computed at the call site when the event is disabled. The int fields are grouped at the end of the entry to avoid padding on 64-bit. scan_folios() is the MGLRU-specific layer where folios are actually scanned, so it has no classic-LRU counterpart. The existing tracepoint is left unchanged. Assisted-by: LLM Signed-off-by: Ridong Chen --- mm/trace_vmscan.h | 66 +++++++++++++++++++++++++++++++++++++++++++++++ mm/vmscan.c | 2 ++ 2 files changed, 68 insertions(+) diff --git a/mm/trace_vmscan.h b/mm/trace_vmscan.h index b2ad83e5f25e..8148b8224422 100644 --- a/mm/trace_vmscan.h +++ b/mm/trace_vmscan.h @@ -392,6 +392,72 @@ TRACE_EVENT(mm_vmscan_lru_isolate, __print_symbolic(__entry->lru, LRU_NAMES)) ); +#ifdef CONFIG_LRU_GEN +TRACE_EVENT(mm_mglru_scan_folios, + + TP_PROTO(struct lruvec *lruvec, + struct scan_control *sc, + unsigned long nr_requested, + unsigned long nr_scanned, + unsigned long nr_sorted, + unsigned long nr_skipped, + unsigned long nr_taken, + int type, + int tier), + + TP_ARGS(lruvec, sc, nr_requested, nr_scanned, nr_sorted, nr_skipped, + nr_taken, type, tier), + + TP_STRUCT__entry( + __field(u64, memcg_id) + __field(unsigned long, nr_requested) + __field(unsigned long, nr_scanned) + __field(unsigned long, nr_sorted) + __field(unsigned long, nr_skipped) + __field(unsigned long, nr_taken) + __field(unsigned long, max_seq) + __field(unsigned long, min_seq) + __field(int, nid) + __field(int, highest_zoneidx) + __field(int, order) + __field(int, lru) + __field(int, tier) + ), + + TP_fast_assign( + __entry->memcg_id = mem_cgroup_id(lruvec_memcg(lruvec)); + __entry->nr_requested = nr_requested; + __entry->nr_scanned = nr_scanned; + __entry->nr_sorted = nr_sorted; + __entry->nr_skipped = nr_skipped; + __entry->nr_taken = nr_taken; + __entry->max_seq = lruvec->lrugen.max_seq; + __entry->min_seq = lruvec->lrugen.min_seq[type]; + __entry->nid = lruvec_pgdat(lruvec)->node_id; + __entry->highest_zoneidx = sc->reclaim_idx; + __entry->order = sc->order; + __entry->lru = type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON; + __entry->tier = tier; + ), + + TP_printk("nid=%d memcg_id=%llu classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_sorted=%lu nr_skipped=%lu nr_taken=%lu lru=%s max_seq=%lu tier=%d min_seq=%lu", + __entry->nid, + __entry->memcg_id, + __entry->highest_zoneidx, + __entry->order, + __entry->nr_requested, + __entry->nr_scanned, + __entry->nr_sorted, + __entry->nr_skipped, + __entry->nr_taken, + __print_symbolic(__entry->lru, LRU_NAMES), + __entry->max_seq, + __entry->tier, + __entry->min_seq) +); + +#endif /* CONFIG_LRU_GEN */ + TRACE_EVENT(mm_vmscan_write_folio, TP_PROTO(struct folio *folio), diff --git a/mm/vmscan.c b/mm/vmscan.c index 5d699decaa28..d459678c5ee5 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4847,6 +4847,8 @@ static int scan_folios(unsigned long nr_to_scan, struct lruvec *lruvec, trace_mm_vmscan_lru_isolate(sc, nr_to_scan, scanned, skipped, isolated, type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON); + trace_mm_mglru_scan_folios(lruvec, sc, nr_to_scan, scanned, sorted, + skipped, isolated, type, tier); *isolatedp = isolated; return scanned; -- 2.34.1