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 1qLPQy-0032l6-5j for pgsql-performance@arkaria.postgresql.org; Mon, 17 Jul 2023 14:42:44 +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 1qLPQw-00AaQ4-IG for pgsql-performance@arkaria.postgresql.org; Mon, 17 Jul 2023 14:42:42 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qLPQw-00AaPo-29 for pgsql-performance@lists.postgresql.org; Mon, 17 Jul 2023 14:42:42 +0000 Received: from mout.gmx.net ([212.227.15.15]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qLPQp-000uuq-2o for pgsql-performance@postgresql.org; Mon, 17 Jul 2023 14:42:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=s31663417; t=1689604952; x=1690209752; i=jimis@gmx.net; bh=cMMW7etGNVlqvA61O/R8DDThlMKPOgJQqvYCDF4Vjwk=; h=X-UI-Sender-Class:Date:From:To:cc:Subject:In-Reply-To:References; b=X+RHBLS1DkO6jvsbsycNJca2v9SeTVhNxLDIrOZToqVYyct536BxI8tGUkefDz4epWwEGRr 75pLuXhSfyOhTMDiPRpn13f8mMJmLrrkes6maS7g/qf0VcPR+ujfjHchZeF/zmwCGNi2l4Gaa 8Ix+RuxSSVf3Y3MCOFp7xA4WLfbGJIvxR92TelZu5JwFVgIZukwqiI8k7At6FgAvL1Jck57/c zxRegRTv/Hz39o+qOvpj/yjX+LMA9UVjYQ5apa3RDLIYJ4/aTjrnbVwWAHXqSfxVnegPTB0yo 8y4azbmM7l+8YV0symNoBZYr37Aq7O09KoHS098T1APE8xu1jHcA== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from [10.9.70.65] ([185.55.107.82]) by mail.gmx.net (mrgmx005 [212.227.17.190]) with ESMTPSA (Nemesis) id 1MEV3I-1qAz2Y1KGI-00G2U2; Mon, 17 Jul 2023 16:42:32 +0200 Date: Mon, 17 Jul 2023 16:42:31 +0200 (CEST) From: Dimitrios Apostolou To: Thomas Munro cc: pgsql-performance@postgresql.org Subject: Re: Performance implications of 8K pread()s In-Reply-To: Message-ID: References: <218fa2e0-bc58-e469-35dd-c5cb35906064@gmx.net> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Provags-ID: V03:K1:0Jr98fj0wptAN7o5WXUBt0EvKOrRymB3fTjdsoja8ZBvfk+a0+P lrG3//6FmEejgFTsljkKtClFSZyPHGI5OQczE6fgiQhFStzaIgNYErCjXNjdhEIeVZ4ryCa kcO7g7u/6E0Aqj98woyDdpHH3wuWyixEEK8gXkSzTHQF5GleSABk6/JDR0QR0IdmxWj6a0O jIfCyXiWavTDDLGjkBpmw== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:FmqIMjauhNI=;TIWmdEOxBu6vD1sUcb5tbZePwr7 nFOLbvBF/mK42HH0VLlygZXFk+Dx/XUz2hIXw2y7+UcN7diRq8ggRpjq486TWfIV1/R7s3vaY rGjvA6xwIC+2e6LJphSoKagW7JV8JkY6Sp8gQr0XUfbKa2efgmgG4W0jKPQ11tzPF0Yr3jSrI KQUP10g8v7uzqFLv7aed1CQiaQ/ZnGYx3u2LCQqNnZi2njD6ZwJQN4zMy5mygd9bJqdSylWnn VNS9DocV+MPJXU0Bekrx+IjCjgMXFW+9V6ZQXt7gKVy9h8K5NVnKb2BnU3RQfHkmNRelndysU JoR7KbkunrwM2mg00ogdmjch+l0j3RW7nu2zIf0pD52E4B6USfqIjQwK+1fL7wlRRT7+NgYKz shozP5RqRcBLmseDs8JOsHxdqHQKCAZJcgaAituS7Fxc48/Ku5yCgyXZwVKvCcmDr5Dx+nlfQ Mub+/hwMw0wfftbPD3CKU0nliuFZphW/TDtjkZqrtm10PICw+34EtQzQ1dqzeJc3h+mucmMI9 T9keaRe6Itd01ioQvxI6pOdm/b+hYfk6b91De3LPyBj76A4jZPHfK4diYbq01JDLtI4Hw5yFt EeRmY0Irbq615LGMxVSwaJeYVrdKtaDm1mMNCiHWCY4/E3vV9OjkPzDXX6pXv+aH6/D3ou9Wn 0YYc4zqI0yFtqCm07U5FuwUgDkQ+nduyE7fBnyNMFfgGpef3MyiU2kAPy7C9rQM8ev5lJVsYm q75/O8lK+wJBCM+UMay5riZ742iSX9VnwwG4iIjemCeMW1VckdfjjuocTGVAoWaiVar5tXmLr 0y/QqkJPWOR7aBGam1MMFGglAw5ciHLV+0rVO/4sW3eo4th2v5lCFeUKIfdDaTnXlFRiFaCCU 8PeWYozmDZbGQXaJB79FUuafwHBGHDkQXo/AJpIw/2JlAN1KjBZMd+3Uk Content-Transfer-Encoding: quoted-printable List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk Thanks, it sounds promising! Are the changes in the 16 branch already, i.e. is it enough to fetch sources for 16-beta2? If so do I just configure --with-liburing (I'm on linux) and run with io_method=3Dio_uring? Else, if I use the io_method=3Dworker what is a sens= ible amount of worker threads? Should I also set all the flags for direct I/O? (io_data_direct=3Don io_wal_direct=3Don).