From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-100.mta0.migadu.com [91.218.175.100]) (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 0C5922DC79F for ; Mon, 7 Sep 2026 04:25:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788755137; cv=none; b=ldpGSyprrQBTUcW0NBDdFB1MhPsSbqlP0E8hMm14IHPgR62uItCJQcD2aLV3CiPJNDSinWb8ggt8Tl103MPhyUdkVFUa7TALcY2iQUnT28jX8jRErlNHJ/Lw8i52UMmHMtLhcPzwTFNRNx1t7hMyZhBxvLIsqMEWoHY8ITjKqV0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788755137; c=relaxed/simple; bh=mK2et90Pf4XLD3r0uXRQiTeVcL8gxLH+/TQolfNphI4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GFt7scywBbQaPPoqR3i5LNeCvSPYV1+nyLakctuGf/UO4ZcH8lMFqhrG1RYPB1upqHwj2ulikAC+ZUSlLzFJdm4UK3+y+DvxIPOfgTe996fHVREAnK9sVGDHXNntebjl1yzKKVdq5Ma1+2hoPvvv3CiXmZQc/cKp5B1QG4GdKnI= 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=JTYxUOTX; arc=none smtp.client-ip=91.218.175.100 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="JTYxUOTX" X-Envelope-To: linux-trace-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=mK2et90Pf4XLD3r0uXRQiTeVcL8gxLH+/TQolfNphI4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1788755134; v=1; x=1789359934; b=JTYxUOTXL1GOPawvOBiUf4pkF8n5ytKR22NHEzOCgWUj42zFrqOXedAn0vV6rG+yJwu3I1Wj P9emkQj7WgF9S/c58Hx8TRX49KFPrj2r2RwdezQAw8NyVjU45iIAxVl7IMeElZBS5OjHb7Wly9m Yh8mFhAud2C9m7BYBP+BLtRE= X-Envelope-To: linux-trace-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f2e3209ee265622f; Mon, 07 Sep 2026 04:25:33 +0000 X-Mizu-Trace-ID: f2e3209ee265622f X-Migadu-Flow: FLOW_OUT From: Ridong Chen To: Steven Rostedt , Masami Hiramatsu , Andrew Morton , Johannes Weiner Cc: Mathieu Desnoyers , David Hildenbrand , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, Ridong Chen , Ridong Chen Subject: [PATCH RFC 2/2] mm/mglru: add tracepoint for inc_max_seq Date: Mon, 7 Sep 2026 12:24:47 +0800 Message-Id: <20260907042447.2450663-3-ridong.chen@linux.dev> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260907042447.2450663-1-ridong.chen@linux.dev> References: <20260907042447.2450663-1-ridong.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Ridong Chen Aging in MGLRU advances max_seq via inc_max_seq(), creating a new youngest generation. There is currently no tracepoint on this path, so the moment a new generation is created, and how the min_seq of each type trails behind it, cannot be observed as it happens. Add mm_mglru_inc_max_seq, emitted right after max_seq is bumped, with the memcg id and the new max_seq alongside the anon and file min_seq. Paired with the mm_mglru_isolate_folios tracepoint it makes the full aging-to-eviction window observable per memcg. Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Ridong Chen --- include/trace/events/vmscan.h | 30 ++++++++++++++++++++++++++++++ mm/vmscan.c | 4 ++++ 2 files changed, 34 insertions(+) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index a0e3cf75294b..ab93c2f4b318 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -439,6 +439,36 @@ TRACE_EVENT(mm_mglru_isolate_folios, __entry->max_seq) ); +TRACE_EVENT(mm_mglru_inc_max_seq, + + TP_PROTO(u64 memcg_id, + unsigned long max_seq, + unsigned long anon_min_seq, + unsigned long file_min_seq), + + TP_ARGS(memcg_id, max_seq, anon_min_seq, file_min_seq), + + TP_STRUCT__entry( + __field(u64, memcg_id) + __field(unsigned long, max_seq) + __field(unsigned long, anon_min_seq) + __field(unsigned long, file_min_seq) + ), + + TP_fast_assign( + __entry->memcg_id = memcg_id; + __entry->max_seq = max_seq; + __entry->anon_min_seq = anon_min_seq; + __entry->file_min_seq = file_min_seq; + ), + + TP_printk("memcg_id=%llu max_seq=%lu anon_min_seq=%lu file_min_seq=%lu", + __entry->memcg_id, + __entry->max_seq, + __entry->anon_min_seq, + __entry->file_min_seq) +); + TRACE_EVENT(mm_vmscan_write_folio, TP_PROTO(struct folio *folio), diff --git a/mm/vmscan.c b/mm/vmscan.c index 771fe6827939..3c806a57d113 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4065,6 +4065,10 @@ static bool inc_max_seq(struct lruvec *lruvec, unsigned long seq, int swappiness WRITE_ONCE(lrugen->timestamps[next], jiffies); /* make sure preceding modifications appear */ smp_store_release(&lrugen->max_seq, lrugen->max_seq + 1); + trace_mm_mglru_inc_max_seq(mem_cgroup_id(lruvec_memcg(lruvec)), + lrugen->max_seq, + lrugen->min_seq[LRU_GEN_ANON], + lrugen->min_seq[LRU_GEN_FILE]); unlock: lruvec_unlock_irq(lruvec); -- 2.34.1