From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.232 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793583900; b=kngrOswWOJ4v5iVS6TcGJOpn92qVwJ/MyGdZIDOt1DUPogVYPubFgYN94bFtVEnYuzQa pMLDDS2K4ILw+NhsF17D9e1W3E3X2Xd3ng6Y7f/e3lC4dVCvnUmcdL4vPpFCS+6jNpsa5 Zq4P2ixha63u2vtvLwqMYiR+mb83WDIMDMW/NQhw0zweu1YtPWlTsr0iO/0Hnqv74ouPV UT3AFSRrmYLMEsUp1YM/YXcICiAhgyWOAyozk0SuDkiY7gfUjmXAeGeHItvqZ00kCjKCJ WSnHpId9oc0PmTtYcZItsIG5BlREnc/JqBG2qnTL5Jx2wwQgvZxO/cAlxUg17qiTQrQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793583900; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=OEkd9ETEU1H1/cSly+n00AuAS0WaAgvozTBt/yDaZw8=; b=eAUIGijjopuIT4/ivru1Kmo3/cbLarz6/NI6q8FtwfYB0HgpwXh/WQY/Xo3VUW5iNZ1H bQqEf9gQNl3bnqZ2C1v2uqsVJn80o4ik9/Bgf5tcWspe4F7fbCsOEMV6QLsYRfnjsYCNZ 6hGEIwA8vLElcgv0pzQPb6bpRCg0OxOxgQoQEmkLnWpyU2ocIiKfhD0/ycEkURo1m0Xdb b1ms7Weae5NtZfkIbLY9lw9pTO3M0h8if12R2vpppInZc2DDJca3eFgaCm2+kQPYDK/oU qMJ/kmcZR3jMHlXnJW3MUDnGZwaTHJvF6ofDIRSvLxiSeAlW5HSNSTmcTKKSMUH6WzA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=IfBo6+HP; arc=none smtp.remote-ip=91.218.175.232 Received: from mta0.migadu.com (out-232.mta0.migadu.com [91.218.175.232]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 54CE0606A324 for ; Mon, 2 Nov 2026 01:44:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 54CE0606A324 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, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=IfBo6+HP X-Envelope-To: linux-trace-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=LDCglTFD9JJRIRS4upbDvcHxcWE5gfnfo+qT8Q0O0nI=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793583897; v=1; x=1794188697; b=IfBo6+HPGHoCqWTW9d7FL3Mpzw7lVFltwm4e1CNHpRdpYX1/oO7kbHAbyScuoA30S2BusA2W cd8BbN3JXJ9mplCKX4Bc6UCX3qNxMIB68maKTGcggwzBi15S5TEKnwqE/7so3LsMq+EmyPo/kcI Qg0dC8Bj3teYPVCcfsZ650SE= X-Envelope-To: linux-trace-kernel@vger.kernel.org Received: by mta11.migadu.com with ESMTPS id 672eb1f5ae80b659; Mon, 02 Nov 2026 01:44:57 +0000 X-Mizu-Trace-ID: 672eb1f5ae80b659 X-Migadu-Flow: FLOW_OUT Date: Mon, 2 Nov 2026 09:44:53 +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 , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baolin Wang , David Hildenbrand , Lorenzo Stoakes , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, "open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)" , "open list:BPF [MISC]:Keyword:(?:b|_)bpf(?:b|_)" , Ridong Chen Subject: Re: [PATCH v5 5/6] mm/mglru: add tracepoint for scan_folios() Message-ID: References: <20261031090041.58574-1-ridong.chen@linux.dev> <20261031090041.58574-6-ridong.chen@linux.dev> X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20261031090041.58574-6-ridong.chen@linux.dev> On 10/31/26 at 05:00pm, Ridong Chen wrote: > 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. > > 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) Now it has nid printed out, it's cool. This patch looks good to me, thanks. Reviewed-by: Baoquan He > + __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 15e9184a580a..ff51fee872f8 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4852,6 +4852,8 @@ 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; > -- > 2.43.0 >