From nobody Fri Dec 19 20:53:45 2025 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0ED1B2DFA25 for ; Wed, 3 Dec 2025 09:55:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764755705; cv=none; b=hCU7TNYXdpl9SjkYDgPoF2eAMbVUZ1IcXDvkFIqP/GTlFR2OynfKJCiyJWTVD8Cu7EGjk613JDGMhQxx9AxQ7XR8GnFpZNlsIHap54uetNFn142hQumhr5MEapQqX0PHhaNzJa7cg2da35nglIRwJtMej7z9uD6MsbVVkfsC/iU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764755705; c=relaxed/simple; bh=jraxpIibHP+8hD5HF14QeXGaHuWC4kNWTzoaGpjZSAc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=i0xbF9+U3BcKlx4bhoSSzeoIlXStW/iKPDiX6e1rE+a/RzNhnivlIwv/kI76pqOztNXyC/PKUZKbqKJy72WlTPtgXVrxZbMz9PbX9EvqBsek+Hgn3MsrnKqBtp3jiJWBQaYVzsTNNaQxYnuUSWZF0+qfpV11e/D+fpR6ctNotbg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4dLtKY0H2BzYQv35 for ; Wed, 3 Dec 2025 17:54:57 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 0160A1A07BD for ; Wed, 3 Dec 2025 17:54:59 +0800 (CST) Received: from hulk-vt.huawei.com (unknown [10.67.174.121]) by APP4 (Coremail) with SMTP id gCh0CgC34Z7nCDBpCm_KAQ--.24312S2; Wed, 03 Dec 2025 17:54:59 +0800 (CST) From: Chen Ridong To: akpm@linux-foundation.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, hannes@cmpxchg.org, david@kernel.org, mhocko@kernel.org, zhengqi.arch@bytedance.com, shakeel.butt@linux.dev, lorenzo.stoakes@oracle.com, yuzhao@google.com, jaewon31.kim@samsung.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, lujialin4@huawei.com, chenridong@huawei.com Subject: [PATCH -next] mm: vmscan: correct nr_requested tracing in scan_folios Date: Wed, 3 Dec 2025 09:40:02 +0000 Message-Id: <20251203094002.1745458-1-chenridong@huaweicloud.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: gCh0CgC34Z7nCDBpCm_KAQ--.24312S2 X-Coremail-Antispam: 1UD129KBjvJXoW7uF15WFyfZFWxXFy8uw4xtFb_yoW8Ww17pa yfur1xGFWfXr4aga4rZwn5Xa17tF42ya47GryYqr1xZ3s3Wa40k345Gr1UX3yxGr1kXryr XasrKFnag3yDtFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvFb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAa w2AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a 6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AK xVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvj xUOBMKDUUUU X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ Content-Type: text/plain; charset="utf-8" From: Chen Ridong When enabling vmscan tracing, it is observed that nr_requested is always 4096, which is confusing. mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... mm_vmscan_lru_isolate: classzone=3D3 order=3D0 nr_requested=3D4096 = ... This is because it prints MAX_LRU_BATCH, which is meaningless as it's a constant. To fix this, modify it to print nr_to_scan as isolate_lru_folios does. Fixes: 8c2214fc9a47 ("mm: multi-gen LRU: reuse some legacy trace events") Signed-off-by: Chen Ridong --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index fddd168a9737..8cfafd50a7a8 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -4601,7 +4601,7 @@ static int scan_folios(unsigned long nr_to_scan, stru= ct lruvec *lruvec, count_memcg_events(memcg, item, isolated); count_memcg_events(memcg, PGREFILL, sorted); __count_vm_events(PGSCAN_ANON + type, isolated); - trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, MAX_LRU_BATCH, + trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan, scanned, skipped, isolated, type ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON); if (type =3D=3D LRU_GEN_FILE) --=20 2.34.1