From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by mail.toke.dk (Postfix) with ESMTPS id 2CC93982E57 for ; Tue, 28 Jun 2022 21:49:50 +0200 (CEST) Authentication-Results: mail.toke.dk; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=PuU/c45w DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656445790; x=1687981790; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=f++W//QJlwHfgm1DNYa0qsrg7yVxZsil1tIeQfMWplE=; b=PuU/c45wzbI02NIiTNolayHvM0mAkqMhOlYj2q0jMssrUb2CFqcOAxZO gNYZbRv2qB0csua5m/9JBj5b8ZeRiowzPOiAXDyWtLWh4JAGyoCWjio2V B2quH6HLLvtM7YgTZbKaAKuc5JIOV5MDE0e7jpwDbnApBciOYfiaoizoi U6uDI4Kh3Iqvuq0MXXve6PIL94VPTNL2yFbuLybwLsO8rEM02CsQ5CqIn 1tlSZiX+/UmqED/VFQncFgK5BwdfmsHBqW2VFcrr9ZxHSBqTbcVhI6zcV E8j5d8Wua4qPC0nGWNhvFdzvJHMrJNSNXHogxZZA6fRP3UU/wpFkvj/6p A==; X-IronPort-AV: E=McAfee;i="6400,9594,10392"; a="345828459" X-IronPort-AV: E=Sophos;i="5.92,229,1650956400"; d="scan'208";a="345828459" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jun 2022 12:49:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.92,229,1650956400"; d="scan'208";a="565181352" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by orsmga006.jf.intel.com with ESMTP; 28 Jun 2022 12:49:43 -0700 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 25SJmr9a022013; Tue, 28 Jun 2022 20:49:41 +0100 From: Alexander Lobakin To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Date: Tue, 28 Jun 2022 21:47:56 +0200 Message-Id: <20220628194812.1453059-37-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220628194812.1453059-1-alexandr.lobakin@intel.com> References: <20220628194812.1453059-1-alexandr.lobakin@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-ID-Hash: SLO2NCMYNB5M5LHBI7FHGBUVNIMTLV3Z X-Message-ID-Hash: SLO2NCMYNB5M5LHBI7FHGBUVNIMTLV3Z X-MailFrom: alexandr.lobakin@intel.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Alexander Lobakin , Larysa Zaremba , Michal Swiatkowski , Jesper Dangaard Brouer , =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= , Magnus Karlsson , Maciej Fijalkowski , Jonathan Lemon , Toke Hoiland-Jorgensen , Lorenzo Bianconi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jesse Brandeburg , John Fastabend , Yajun Deng , Willem de Bruijn , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, xdp-hints@xdp-project.net X-Mailman-Version: 3.3.5 Precedence: list Subject: [xdp-hints] [PATCH RFC bpf-next 36/52] bpf, cpumap: switch to napi_skb_cache_get_bulk() List-Id: XDP hardware hints design discussion Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Now that cpumap uses GRO, which drops unused skb heads to the NAPI cache, use napi_skb_cache_get_bulk() to try to reuse cached entries and lower the MM layer pressure. In the situation when all 8 skbs from one cpumap batch goes into one GRO skb (so the rest 7 go into the cache), there will now be only 1 skb to allocate per cycle instead of 8. If there is some other work happening in between the cycles, even all 8 might be getting decached each cycle. This makes the BH-off period per each batch slightly longer -- previously, skb allocation was happening in the process context. Signed-off-by: Alexander Lobakin --- kernel/bpf/cpumap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 145f49de0931..1bb3ae570e6c 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -365,7 +365,6 @@ static int cpu_map_kthread_run(void *data) while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { struct xdp_cpumap_stats stats = {}; /* zero stats */ unsigned int kmem_alloc_drops = 0, sched = 0; - gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; int i, n, m, nframes, xdp_n; void *frames[CPUMAP_BATCH]; void *skbs[CPUMAP_BATCH]; @@ -416,8 +415,10 @@ static int cpu_map_kthread_run(void *data) /* Support running another XDP prog on this CPU */ nframes = cpu_map_bpf_prog_run(rcpu, frames, xdp_n, &stats, &list); + local_bh_disable(); + if (nframes) { - m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs); + m = napi_skb_cache_get_bulk(skbs, nframes); if (unlikely(m == 0)) { for (i = 0; i < nframes; i++) skbs[i] = NULL; /* effect: xdp_return_frame */ @@ -425,7 +426,6 @@ static int cpu_map_kthread_run(void *data) } } - local_bh_disable(); for (i = 0; i < nframes; i++) { struct xdp_frame *xdpf = frames[i]; struct sk_buff *skb = skbs[i]; -- 2.36.1