Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1tWKY7-00FqPl-Te for pgsql-hackers@arkaria.postgresql.org; Fri, 10 Jan 2025 19:20:04 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1tWKY7-00247p-DY for pgsql-hackers@arkaria.postgresql.org; Fri, 10 Jan 2025 19:20:03 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1tWKY7-00247h-4M for pgsql-hackers@lists.postgresql.org; Fri, 10 Jan 2025 19:20:02 +0000 Received: from mail-il1-x130.google.com ([2607:f8b0:4864:20::130]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1tWKY3-000xUW-33 for pgsql-hackers@postgresql.org; Fri, 10 Jan 2025 19:20:02 +0000 Received: by mail-il1-x130.google.com with SMTP id e9e14a558f8ab-3a9cb8460f7so14796525ab.2 for ; Fri, 10 Jan 2025 11:20:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1736536797; x=1737141597; darn=postgresql.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=e0m++sn692ftZE0z9mzxQXUvgw6lAa+BlAVl25Wgems=; b=Bhp1qOUHRj0ZQ0R2E18inXPxvjsN8J1mfqG7/B4OoEsLWmHv3ogN+iX/Cj0UzAN8Q3 K1TCh0bghkQQiB17sqAIRwBWk/hhHRDShqPg6+44gQv0B3tmbRw+x2wIojHb4sXyX2Md jzBOy7AgDHfKlhf1YRoW2lXZhBiVX5y1pcTzrKMEN15JNaTAE6mCM2BQ27sekR8ueKut NxoNJKHrJVQBaKmgaK2L/7Z12FlJik3L+XFLVkSTzPv3xD4x0jD+2CgPMKtF7fcK9gC4 BbwQsYTeZzrTyOJ+Hyz2P2eciLxx7fw0EkfDLRPKru5wUj467WFtARdawMoq/gqtaWVn ddCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736536797; x=1737141597; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=e0m++sn692ftZE0z9mzxQXUvgw6lAa+BlAVl25Wgems=; b=hPAzpbvwfEMXughcWV/67+UuzoUS0h7StLAWOydfxfLsYJRyi/vK+UMiOtIz6WtFN3 e84Ymr8l0k1BHnSyOUYnvM9nTxDPHwVJSImWQM0pGLg5WaC603KQWOLZw+IdvGYHjCIF /82IOr3FSFPBFEoU63b0gEn/X1dfwLmEio2P2RsP2+gu7sL1K3prd85SSTng7PebN5S/ vVDbk+kEf7Vvk6JMhv2nN0hUUxX5Qwd/oncRUZH/sM4gM2/Vh0WWenEyR1YnW4YTJ/c7 /QgpCEmWRiz1oIf5fytf22uUuCHuWdoek08N/bgfvx5nAL62NG4iK/d4R23FA4l1g4j1 sqMQ== X-Gm-Message-State: AOJu0Yys32ny/b/skkOU0gC7JBovd55xJE2e/9RSLx+NnrB0qHlF3edW Yr9UI/irV37NrD+yAQCXdLAonlJ9sLkMzDNko+Txzu8tqZ5DVvee X-Gm-Gg: ASbGncuhi9kXXI2FMYvoe+T55NaPSFLxVII3U85tXdqNFlU7wi88qR1sKLDlSTJ1T8R 8+0+lnTNxXadmW8JcBc9y4eZWAdCqTqIc0O3RLxzSUEuJIJGPqA9Z6Gywc8jz1wGwFuumzUthF6 UgvUf9Oav76ht9nWKP0F/+Y9UKjKBXIGluUTSj+HwARuP0t8QniHRsricxpbdggzl8in9Q532g8 t/khlskoLHolvZeSblGN74heeruK21a6c0KFW29IIuPUUzAj6X47QaDrT781c7Ers1ekicNsUPq UiJy0pJU7IQpoXugBTsVh5AixrzFDd8OhRf2JQ3Jtw4wlAE= X-Google-Smtp-Source: AGHT+IHn8KyxmtawS9sdV7m3zREw/t609CxpGtcD6uJ5JLKe4gIL1XkYiBifjqudM9Se2snqg4FIUQ== X-Received: by 2002:a05:6e02:1a86:b0:3a7:1a65:2fbd with SMTP id e9e14a558f8ab-3ce3a8bb194mr86326155ab.17.1736536797380; Fri, 10 Jan 2025 11:19:57 -0800 (PST) Received: from nathan (162-195-168-172.lightspeed.stlsmo.sbcglobal.net. [162.195.168.172]) by smtp.gmail.com with ESMTPSA id e9e14a558f8ab-3ce4add9b01sm11174955ab.40.2025.01.10.11.19.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jan 2025 11:19:56 -0800 (PST) Date: Fri, 10 Jan 2025 13:19:55 -0600 From: Nathan Bossart To: Andres Freund Cc: pgsql-hackers@postgresql.org, dipiets@amazon.com Subject: Re: use a non-locking initial test in TAS_SPIN on AArch64 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Fri, Jan 10, 2025 at 10:51:40AM -0600, Nathan Bossart wrote: > Actually, I think I may have just had back luck and/or not warmed things up > enough. I just re-ran the test a few dozen times, carefully ensuring the > data was in the cache and periodically alternating between the binary with > the patch applied and the one without it. The results converged to within > 1-2% of each other, with the patched version even winning about half the > time. The averages across all the runs showed a ~0.4% regression, which I > suspect is well within the noise range. I went ahead and committed this patch. Please let me know if there are any remaining concerns. -- nathan