From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f98.google.com (mail-wm1-f98.google.com [209.85.128.98]) (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 2AEEE4C957B for ; Wed, 16 Sep 2026 23:25:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.98 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789601148; cv=none; b=JNIscOBZOEeyTXMmzJk/WzlvRU9sERbgd3uB27BDzFmfoFUy1cflw+EMMSFRrkMwavoc6kxHFEfvvHlUrYRNvR2UXihm/EW/2Dw+LaqLV5PnDa+ikgOtPcQ0iqutyCQv106BiPCZtSK10ifKzqOv94HNRff4R5aoEE8/qPkocFU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789601148; c=relaxed/simple; bh=abZ+0AvUY4oazPRqaXspWDPFpaIpjOBE+mBXBPZkJLw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=tD5UmjBf3PgUxCVziziwbsN0z4pVzE38FJ3b7/R0IXtGyC5q34lSo8t2k4Az0imv9tImdmqpUKGEy15UXaEJeEQieUEGNLd0wWDYlFKIou69XLkx8aj9DWtH78/a7hAHqd8U98MxMtXBIlom+5gZKTQNQV/sGm1eOWvPXmjQq+w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=everpuredata.com; spf=pass smtp.mailfrom=everpuredata.com; dkim=pass (2048-bit key) header.d=everpuredata.com header.i=@everpuredata.com header.b=Xf72g0Hz; arc=none smtp.client-ip=209.85.128.98 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=everpuredata.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=everpuredata.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=everpuredata.com header.i=@everpuredata.com header.b="Xf72g0Hz" Received: by mail-wm1-f98.google.com with SMTP id 5b1f17b1804b1-49e73611928so927895e9.1 for ; Wed, 16 Sep 2026 16:25:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=everpuredata.com; s=google; t=1789601145; x=1790205945; 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:content-type; bh=PPMmzeMGw5inM8GWwOz7lS3Of5P0aQnoyqgcSMcVsuo=; b=Xf72g0HzpXjPRHx/aZbRnuHo7gLoR9zyhVlhb6+DSotRD3cjWSKzlmDIyR4mjbXjG4 9+kE0dy0h1XQN27MlrUc4NgMYzl53IzqfY62FozdGeMPBKEv8MtfA4OpaAnAetrkp1RG /XDmX5YPdS/EJuYlFWZL+x9zX0qcjjV0WBSdE1wlLA0gwvtCK7g/v0M7LihfmxajNbm5 cqS+3nlUevJHEJHD3pBYNAU+6AxGvYTzJYDbV5FALCPLK7ip3pTguriFFHqfDPQ/Vl1y 3yQs5qS5rTo88jlYVNbniOL6Y9Y3OWpYn1mKeEC7BGpZPb5kRcJvz+gilRIpBrhhCE89 zhmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789601145; x=1790205945; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=PPMmzeMGw5inM8GWwOz7lS3Of5P0aQnoyqgcSMcVsuo=; b=SaPM6AHY4rS9ONre1zYS+UEahWMTax7TfUeGQSqy+fjpvQaGW05vsNDvjkcTTWbGZK BkvvZhm3QRvKAlDqjGajjsarKN7GdI/sfPm9jGtKwp1pRP0LiNZ2ullRPk/I7wNAN9bg rzytKXKjgzTJ9BMYlokTgXurXZHXX6GIzXsOYBtmWApoJfTLsnkxmPtQ7tS4Mi4+Akrw n0LlV6ZKRA6y9UgefBdQPmFbXR5l4vsryR4wF0C3BuWzi3LAUtzbZucrNQ4w/ZlR8YpH eCC6wVzbbUiq5yMkMPnOxnPK6UJfKfOuJ4Rgp70DcqGYvgLzDlSsc6FpvmnU1TdQgh9P hBUg== X-Forwarded-Encrypted: i=1; AKwUvBzSYcW1kMjWEgS3MHww2agEqsfJvyvc52hfclbJyOxFgGySkHEd5sWBOpY/fJvQTYeyW0zVZaAWejAvQBc=@vger.kernel.org X-Gm-Message-State: AFuF++mFu7wTEeO1EczeLz97RPL8OPNs3izpYzV3bCNclb4N1L0whpZ4 DqbK8aTHd4gX8PEOErQJW47DvHjtPxAUxKGDfBn7Zar8WPwymZVX/lQpC/f2hCJ9e2vwOQIbzXl miHhP5CghNHny2dX0WJgBucq1++2poCFmCUlE X-Gm-Gg: AYBFou1HzvGplXoVMH5SS+Brh8V1z1PEp8he6AuLCYUDBHEs/ZaO1BYzN0piSd/leL2 ec5Ut1JgqghkfxVjTPPaSINs5gMqlPhKSxoCn6aXZ2Sn3YNhMCw58kqz2qDQY1mKGmLzfNqKJrx wkoPcmYu5fh5nKiFjbdUhmiNFJhsi5ua4hHA/sJ7TorvUIqmdkSRDe9QCX7EhOR5hOHyfwmuvVH gZR4TqtaFNXp1oVsgJbW4clYwGkkkibjnk+CkXt7zG8zlMmUusssiOlRXjKMG+2kVG42SfIAawa esvofL1cjIyoi92ePNRzOwCDJ86akoNEplWFhsXBK0Z8I2nKe8vmL7kTKWx6+JPClpDLcMHV+Bg 8+SezMf6docelLPoBEqzLraM11faacDrTWhrrIyo= X-Received: by 2002:a05:600d:8643:20b0:49e:7c8c:bc77 with SMTP id 5b1f17b1804b1-49fbd1c9005mr12325555e9.7.1789601145442; Wed, 16 Sep 2026 16:25:45 -0700 (PDT) Received: from c14-smtp-2023.dev.purestorage.com ([208.88.158.128]) by smtp-relay.gmail.com with ESMTPS id 5b1f17b1804b1-49fbd520ad4sm1982415e9.1.2026.09.16.16.25.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2026 16:25:45 -0700 (PDT) X-Relaying-Domain: everpuredata.com Received: from irdv-tmenninger.dev.purestorage.com (irdv-tmenninger.dev.purestorage.com [10.32.149.15]) by c14-smtp-2023.dev.purestorage.com (Postfix) with ESMTPS id D574934014B; Wed, 16 Sep 2026 16:25:43 -0700 (PDT) From: Tim Menninger To: Chuck Lever Cc: Trond Myklebust , Anna Schumaker , Tejun Heo , Lai Jiangshan , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Badger , Jon Curley Subject: Re: [PATCH RFC 6/8] SUNRPC: Reduce rpciod workqueue contention Date: Wed, 16 Sep 2026 23:25:43 +0000 Message-Id: <20260916232543.4100078-1-tmenninger@everpuredata.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <0e2f9688-097c-4bb9-a7ec-82b41bdb3653@slotpi15m67> References: <0e2f9688-097c-4bb9-a7ec-82b41bdb3653@slotpi15m67> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit I took the SLUB side of this to linux-mm as you suggested: https://lore.kernel.org/linux-mm/20260916232227.4098143-1-tmenninger@everpuredata.com/ The more careful reruns also resolved the inconsistency you pointed out between the perf-lock wait time and the idle CPU measurement. When mpstat is collected during the same 10-second perf-lock window, the machine is almost fully utilized and throughput drops substantially; without that instrumentation there is significant idle CPU remaining. I also collected cmpxchg_double_fail over uninstrumented 10-second windows in several NUMA/CQ placements. Those numbers are included in the linux-mm report. Thanks again for helping separate the allocator behavior from the NFS regression.