From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) (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 D90D7153BCE for ; Mon, 22 Apr 2024 16:17:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.78.197.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713802641; cv=none; b=paxW+dy3VjtmLfxlvvlZzybmzuQTBA6hUTG9DnVv5+Vh2s5eCJ89f8TevPJ3Ngjt1PxVQBOoc+2gj0ZiqAxGBTLlgFFnmpWcuqeA0/0HYyZ8Y8X4zpjGADLUlYDPTvM2/tGg0GT5fyo1xPaBWb2LlkAA6JIHbMOh0tGRwQEsf+0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713802641; c=relaxed/simple; bh=kPtHa1h75L0L9bPKO9qdnWB5Z/ik7V/Q4elzb5V6T+M=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=al3qkKiqgz24VVFEeJReke1R7VVTCHaMJqJtUQaVOEI2LQTxsXYAYyZeSb5zfmCqpZwb1oIrf3NrPeVHRKU8G+PNN4c/v7LHT9RxGS9W/wFsOAcPi1i1I1j4s3Jpm6+iD2Wi6QLkKrUOCA2bu6pCBiAIyJ9jUuxumfXyC8gbauQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.uk; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=TuOMPPnH; arc=none smtp.client-ip=99.78.197.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="TuOMPPnH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1713802639; x=1745338639; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=mrah453q2MFwXAq9wjp65lEluNdemNuwyBu10e18TxE=; b=TuOMPPnHy9F49fdyHu2mNp0BeZGKZueBpuujYzT7jyp1s1wFA8CUQHCk Xbxz20i/RQ0xLoCJOWyCzywulPDTtLkXDRhB3dGgmFMBIz5YrFzcUx7DV Z/7ruhvXN+tMxrGIB/BwQ0hLEHF9kENCAHkttAD8PmpxVJtAQrdNVou5+ A=; X-IronPort-AV: E=Sophos;i="6.07,221,1708387200"; d="scan'208";a="290865115" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.25.36.210]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Apr 2024 16:17:17 +0000 Received: from EX19MTAEUC002.ant.amazon.com [10.0.10.100:7206] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.8.194:2525] with esmtp (Farcaster) id 57717e08-bd6f-460b-b357-06035a32e564; Mon, 22 Apr 2024 16:17:15 +0000 (UTC) X-Farcaster-Flow-ID: 57717e08-bd6f-460b-b357-06035a32e564 Received: from EX19D038EUA003.ant.amazon.com (10.252.50.199) by EX19MTAEUC002.ant.amazon.com (10.252.51.245) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.28; Mon, 22 Apr 2024 16:17:15 +0000 Received: from c889f3b7ef0b.amazon.com (10.119.243.178) by EX19D038EUA003.ant.amazon.com (10.252.50.199) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1258.28; Mon, 22 Apr 2024 16:17:13 +0000 From: Salvatore Dipietro To: CC: , , , , , , , , , Subject: Re: [PATCH v3] tcp: Add memory barrier to tcp_push() Date: Mon, 22 Apr 2024 09:16:56 -0700 Message-ID: <20240422161656.60331-1-dipiets@amazon.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D037UWB003.ant.amazon.com (10.13.138.115) To EX19D038EUA003.ant.amazon.com (10.252.50.199) We have tested the proposed solution and it doesn't introduce any regression in our benchmark. Moreover, looking to the assembly code, the `test_and_set_bit` generates an `ldsetal` and `dmb ish` instructions which are correct for the ARM architecture. We do not see any concern with the proposed patch.