From nobody Wed Feb 11 04:00:56 2026 Received: from mail-pl1-f171.google.com (mail-pl1-f171.google.com [209.85.214.171]) (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 8AA7951C4B for ; Mon, 22 Apr 2024 07:43:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713771797; cv=none; b=O3imbOQ4gHK9opFc/C1bownQu0YxG95dqfaQ/7WrNwQaSnWPTv+9MyT6EKRI9VU3Hwic3NRnoosBy4DLcWRpsUikBml7KvyVGfJA+DQIe2HnLDdAecVF1GJWcBPbuM3h8ZO/5saA4uKzE1OmZXOQrQEe/jAIydhhpUXMUsoeNsk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713771797; c=relaxed/simple; bh=B7vOTsSVYsGFUvhOXvJRAjHPNDIwccqInso5hXY7xSM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tVkTzVHBumubVuybBGh1y61aF1DLQvrQWBFiPG+mP02YTh5tg4IB4sJC/WgKnPPFHKWxZUCVB03W4iKqvgQzIdE8K3Tdkp4pdReCANrzDyFE7vKlf6IzmaGy6CJ89pzVFoP1tNH6IRQH8ABqVhUJSHW0mcgXV2pxdAxZQC5I7bs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=PvONompd; arc=none smtp.client-ip=209.85.214.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="PvONompd" Received: by mail-pl1-f171.google.com with SMTP id d9443c01a7336-1e4bf0b3e06so39389555ad.1 for ; Mon, 22 Apr 2024 00:43:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1713771795; x=1714376595; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=bBFXolLQYa78XCdQIXx8hSsPDNH1h31ohatbB+q7SSA=; b=PvONompda1dfJWMA4hcgQXLuxfy8W0c47dT8l4VjtbvsdZMHh1/H+1G77fxzOB/2o4 sAq4/fuQvArbunkiUxQXvV32zBLQbmjrRuH7UUmfqyUnTHTYVrlM9fBpiAe/BpP3zU3J qTN3jnAFsftUmHVUSvuApgN/8DAeM1F/TtMVsSSWTv9iOq9Q8xQmErbsoKZuWq6YzXKQ ShfUM8yysTxW39Nr8U6cQxG+DqQvvwlb2mE1Gg/WvZEpiHVqWgvBppN6VwCJWzf/5JmT g0kdz4a1U0XPcCvllo+pqq1HYfyukVg04/RKktlngHZ3OSY6jOgG1hr6epIjNr+vGjcH N5vA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713771795; x=1714376595; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bBFXolLQYa78XCdQIXx8hSsPDNH1h31ohatbB+q7SSA=; b=SP2fl25YF4Y4uOTOX+e4TYNkTaAEm7pQ3ZBab5pApVxyKVRYNsbhiGTeWGA9QqDxDc 7Sa7SdaX9yHZidJlMGi0PqG/PmikYHS1RMBhqk4lvHTb+3Y7QTR7qtUV5e2WzFvEbBOr pDeboRmH8BAbfNibSENbC9J85F+D26Axh6/eC17rEybFbnoBTHfLYJ+xsF7oyNEg88OG hGAxxyiwx4xkdqU5ag/T/YtSJOZQqzNXJWcyFKvDFl9HaP3S4tmhUePMccySgo+Vzf/4 izcMAXHfA289fxtBS1iIIs7gnYpMneehJ5GUmqP8/ef7uIp5+YxSGjUvQP7KsvXi6Not 58wA== X-Gm-Message-State: AOJu0YzV/+2Pct/9PYMH8uJxKEoo4UjbGZpv9Ah554abgpUtf8jXBXn0 gf6IFn90otHtaNQpNoLOuuP3jeNXsvnaQASVrTzp1dyIT147vhKJwYuSmGuBNlIvS7pFZx+kCzb E X-Google-Smtp-Source: AGHT+IEvHT3XYAnqbJeBRBtYXwHjzJuRWUr3q0IHkM4UWpx7JR4+gVdQqRx7dbo9nSIw0pAVB8jXbw== X-Received: by 2002:a17:902:784f:b0:1e4:d548:818f with SMTP id e15-20020a170902784f00b001e4d548818fmr9126943pln.58.1713771795591; Mon, 22 Apr 2024 00:43:15 -0700 (PDT) Received: from libai.bytedance.net ([61.213.176.11]) by smtp.gmail.com with ESMTPSA id e11-20020a170902784b00b001e0bae4490fsm7595634pln.154.2024.04.22.00.43.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Apr 2024 00:43:15 -0700 (PDT) From: zhenwei pi To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux.dev Cc: mst@redhat.com, david@redhat.com, jasowang@redhat.com, xuanzhuo@linux.alibaba.com, akpm@linux-foundation.org, zhenwei pi Subject: [PATCH v2 4/4] virtio_balloon: introduce memory scan/reclaim info Date: Mon, 22 Apr 2024 15:42:54 +0800 Message-Id: <20240422074254.1440457-5-pizhenwei@bytedance.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240422074254.1440457-1-pizhenwei@bytedance.com> References: <20240422074254.1440457-1-pizhenwei@bytedance.com> 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 Content-Type: text/plain; charset="utf-8" Expose memory scan/reclaim information to the host side via virtio balloon device. Now we have a metric to analyze the memory performance: y: counter increases n: counter does not changes h: the rate of counter change is high l: the rate of counter change is low OOM: VIRTIO_BALLOON_S_OOM_KILL STALL: VIRTIO_BALLOON_S_ALLOC_STALL ASCAN: VIRTIO_BALLOON_S_SCAN_ASYNC DSCAN: VIRTIO_BALLOON_S_SCAN_DIRECT ARCLM: VIRTIO_BALLOON_S_RECLAIM_ASYNC DRCLM: VIRTIO_BALLOON_S_RECLAIM_DIRECT - OOM[y], STALL[*], ASCAN[*], DSCAN[*], ARCLM[*], DRCLM[*]: the guest runs under really critial memory pressure - OOM[n], STALL[h], ASCAN[*], DSCAN[l], ARCLM[*], DRCLM[l]: the memory allocation stalls due to cgroup, not the global memory pressure. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[h]: the memory allocation stalls due to global memory pressure. The performance gets hurt a lot. A high ratio between DRCLM/DSCAN shows quite effective memory reclaiming. - OOM[n], STALL[h], ASCAN[*], DSCAN[h], ARCLM[*], DRCLM[l]: the memory allocation stalls due to global memory pressure. the ratio between DRCLM/DSCAN gets low, the guest OS is thrashing heavily, the serious case leads poor performance and difficult trouble shooting. Ex, sshd may block on memory allocation when accepting new connections, a user can't login a VM by ssh command. - OOM[n], STALL[n], ASCAN[h], DSCAN[n], ARCLM[l], DRCLM[n]: the low ratio between ARCLM/ASCAN shows that the guest tries to reclaim more memory, but it can't. Once more memory is required in future, it will struggle to reclaim memory. Acked-by: David Hildenbrand Signed-off-by: zhenwei pi --- drivers/virtio/virtio_balloon.c | 9 +++++++++ include/uapi/linux/virtio_balloon.h | 12 ++++++++++-- 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloo= n.c index ab039e83bc6f..e45146fde164 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -341,6 +341,15 @@ static inline unsigned int update_balloon_vm_stats(str= uct virtio_balloon *vb, =20 update_stat(vb, idx++, VIRTIO_BALLOON_S_ALLOC_STALL, stall); =20 + update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_SCAN, + pages_to_bytes(events[PGSCAN_KSWAPD])); + update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_SCAN, + pages_to_bytes(events[PGSCAN_DIRECT])); + update_stat(vb, idx++, VIRTIO_BALLOON_S_ASYNC_RECLAIM, + pages_to_bytes(events[PGSTEAL_KSWAPD])); + update_stat(vb, idx++, VIRTIO_BALLOON_S_DIRECT_RECLAIM, + pages_to_bytes(events[PGSTEAL_DIRECT])); + #ifdef CONFIG_HUGETLB_PAGE update_stat(vb, idx++, VIRTIO_BALLOON_S_HTLB_PGALLOC, events[HTLB_BUDDY_PGALLOC]); diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virti= o_balloon.h index 487b893a160e..ee35a372805d 100644 --- a/include/uapi/linux/virtio_balloon.h +++ b/include/uapi/linux/virtio_balloon.h @@ -73,7 +73,11 @@ struct virtio_balloon_config { #define VIRTIO_BALLOON_S_HTLB_PGFAIL 9 /* Hugetlb page allocation failu= res */ #define VIRTIO_BALLOON_S_OOM_KILL 10 /* OOM killer invocations */ #define VIRTIO_BALLOON_S_ALLOC_STALL 11 /* Stall count of memory allocat= oin */ -#define VIRTIO_BALLOON_S_NR 12 +#define VIRTIO_BALLOON_S_ASYNC_SCAN 12 /* Amount of memory scanned asyn= chronously */ +#define VIRTIO_BALLOON_S_DIRECT_SCAN 13 /* Amount of memory scanned dire= ctly */ +#define VIRTIO_BALLOON_S_ASYNC_RECLAIM 14 /* Amount of memory reclaimed as= ynchronously */ +#define VIRTIO_BALLOON_S_DIRECT_RECLAIM 15 /* Amount of memory reclaimed d= irectly */ +#define VIRTIO_BALLOON_S_NR 16 =20 #define VIRTIO_BALLOON_S_NAMES_WITH_PREFIX(VIRTIO_BALLOON_S_NAMES_prefix) = { \ VIRTIO_BALLOON_S_NAMES_prefix "swap-in", \ @@ -87,7 +91,11 @@ struct virtio_balloon_config { VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-allocations", \ VIRTIO_BALLOON_S_NAMES_prefix "hugetlb-failures", \ VIRTIO_BALLOON_S_NAMES_prefix "oom-kills", \ - VIRTIO_BALLOON_S_NAMES_prefix "alloc-stalls" \ + VIRTIO_BALLOON_S_NAMES_prefix "alloc-stalls", \ + VIRTIO_BALLOON_S_NAMES_prefix "async-scans", \ + VIRTIO_BALLOON_S_NAMES_prefix "direct-scans", \ + VIRTIO_BALLOON_S_NAMES_prefix "async-reclaims", \ + VIRTIO_BALLOON_S_NAMES_prefix "direct-reclaims" \ } =20 #define VIRTIO_BALLOON_S_NAMES VIRTIO_BALLOON_S_NAMES_WITH_PREFIX("") --=20 2.34.1