From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) by lore.proxmox.com (Postfix) with ESMTPS id 0C3C61FF168 for ; Mon, 14 Oct 2024 10:42:07 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 42391308CD; Mon, 14 Oct 2024 10:42:36 +0200 (CEST) Message-ID: Date: Mon, 14 Oct 2024 10:42:02 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta To: Proxmox VE development discussion , Filip Schauer References: <20240930114045.76730-1-f.schauer@proxmox.com> Content-Language: en-GB, de-AT From: Thomas Lamprecht Autocrypt: addr=t.lamprecht@proxmox.com; keydata= xsFNBFsLjcYBEACsaQP6uTtw/xHTUCKF4VD4/Wfg7gGn47+OfCKJQAD+Oyb3HSBkjclopC5J uXsB1vVOfqVYE6PO8FlD2L5nxgT3SWkc6Ka634G/yGDU3ZC3C/7NcDVKhSBI5E0ww4Qj8s9w OQRloemb5LOBkJNEUshkWRTHHOmk6QqFB/qBPW2COpAx6oyxVUvBCgm/1S0dAZ9gfkvpqFSD 90B5j3bL6i9FIv3YGUCgz6Ue3f7u+HsEAew6TMtlt90XV3vT4M2IOuECG/pXwTy7NtmHaBQ7 UJBcwSOpDEweNob50+9B4KbnVn1ydx+K6UnEcGDvUWBkREccvuExvupYYYQ5dIhRFf3fkS4+ wMlyAFh8PQUgauod+vqs45FJaSgTqIALSBsEHKEs6IoTXtnnpbhu3p6XBin4hunwoBFiyYt6 YHLAM1yLfCyX510DFzX/Ze2hLqatqzY5Wa7NIXqYYelz7tXiuCLHP84+sV6JtEkeSUCuOiUY virj6nT/nJK8m0BzdR6FgGtNxp7RVXFRz/+mwijJVLpFsyG1i0Hmv2zTn3h2nyGK/I6yhFNt dX69y5hbo6LAsRjLUvZeHXpTU4TrpN/WiCjJblbj5um5eEr4yhcwhVmG102puTtuCECsDucZ jpKpUqzXlpLbzG/dp9dXFH3MivvfuaHrg3MtjXY1i+/Oxyp5iwARAQABzTNUaG9tYXMgTGFt cHJlY2h0IChBdXRoLTQpIDx0LmxhbXByZWNodEBwcm94bW94LmNvbT7CwY4EEwEIADgWIQQO R4qbEl/pah9K6VrTZCM6gDZWBgUCWwuNxgIbAwULCQgHAgYVCAkKCwIEFgIDAQIeAQIXgAAK CRDTZCM6gDZWBm/jD/4+6JB2s67eaqoP6x9VGaXNGJPCscwzLuxDTCG90G9FYu29VcXtubH/ bPwsyBbNUQpqTm/s4XboU2qpS5ykCuTjqavrcP33tdkYfGcItj2xMipJ1i3TWvpikQVsX42R G64wovLs/dvpTYphRZkg5DwhgTmy3mRkmofFCTa+//MOcNOORltemp984tWjpR3bUJETNWpF sKGZHa3N4kCNxb7A+VMsJZ/1gN3jbQbQG7GkJtnHlWkw9rKCYqBtWrnrHa4UAvSa9M/XCIAB FThFGqZI1ojdVlv5gd6b/nWxfOPrLlSxbUo5FZ1i/ycj7/24nznW1V4ykG9iUld4uYUY86bB UGSjew1KYp9FmvKiwEoB+zxNnuEQfS7/Bj1X9nxizgweiHIyFsRqgogTvLh403QMSGNSoArk tqkorf1U+VhEncIn4H3KksJF0njZKfilrieOO7Vuot1xKr9QnYrZzJ7m7ZxJ/JfKGaRHXkE1 feMmrvZD1AtdUATZkoeQtTOpMu4r6IQRfSdwm/CkppZXfDe50DJxAMDWwfK2rr2bVkNg/yZI tKLBS0YgRTIynkvv0h8d9dIjiicw3RMeYXyqOnSWVva2r+tl+JBaenr8YTQw0zARrhC0mttu cIZGnVEvQuDwib57QLqMjQaC1gazKHvhA15H5MNxUhwm229UmdH3KM7BTQRbC43GARAAyTkR D6KRJ9Xa2fVMh+6f186q0M3ni+5tsaVhUiykxjsPgkuWXWW9MbLpYXkzX6h/RIEKlo2BGA95 QwG5+Ya2Bo3g7FGJHAkXY6loq7DgMp5/TVQ8phsSv3WxPTJLCBq6vNBamp5hda4cfXFUymsy HsJy4dtgkrPQ/bnsdFDCRUuhJHopnAzKHN8APXpKU6xV5e3GE4LwFsDhNHfH/m9+2yO/trcD txSFpyftbK2gaMERHgA8SKkzRhiwRTt9w5idOfpJVkYRsgvuSGZ0pcD4kLCOIFrer5xXudk6 NgJc36XkFRMnwqrL/bB4k6Pi2u5leyqcXSLyBgeHsZJxg6Lcr2LZ35+8RQGPOw9C0ItmRjtY ZpGKPlSxjxA1WHT2YlF9CEt3nx7c4C3thHHtqBra6BGPyW8rvtq4zRqZRLPmZ0kt/kiMPhTM 8wZAlObbATVrUMcZ/uNjRv2vU9O5aTAD9E5r1B0dlqKgxyoImUWB0JgpILADaT3VybDd3C8X s6Jt8MytUP+1cEWt9VKo4vY4Jh5vwrJUDLJvzpN+TsYCZPNVj18+jf9uGRaoK6W++DdMAr5l gQiwsNgf9372dbMI7pt2gnT5/YdG+ZHnIIlXC6OUonA1Ro/Itg90Q7iQySnKKkqqnWVc+qO9 GJbzcGykxD6EQtCSlurt3/5IXTA7t6sAEQEAAcLBdgQYAQgAIBYhBA5HipsSX+lqH0rpWtNk IzqANlYGBQJbC43GAhsMAAoJENNkIzqANlYGD1sP/ikKgHgcspEKqDED9gQrTBvipH85si0j /Jwu/tBtnYjLgKLh2cjv1JkgYYjb3DyZa1pLsIv6rGnPX9bH9IN03nqirC/Q1Y1lnbNTynPk IflgvsJjoTNZjgu1wUdQlBgL/JhUp1sIYID11jZphgzfDgp/E6ve/8xE2HMAnf4zAfJaKgD0 F+fL1DlcdYUditAiYEuN40Ns/abKs8I1MYx7Yglu3RzJfBzV4t86DAR+OvuF9v188WrFwXCS RSf4DmJ8tntyNej+DVGUnmKHupLQJO7uqCKB/1HLlMKc5G3GLoGqJliHjUHUAXNzinlpE2Vj C78pxpwxRNg2ilE3AhPoAXrY5qED5PLE9sLnmQ9AzRcMMJUXjTNEDxEYbF55SdGBHHOAcZtA kEQKub86e+GHA+Z8oXQSGeSGOkqHi7zfgW1UexddTvaRwE6AyZ6FxTApm8wq8NT2cryWPWTF BDSGB3ujWHMM8ERRYJPcBSjTvt0GcEqnd+OSGgxTkGOdufn51oz82zfpVo1t+J/FNz6MRMcg 8nEC+uKvgzH1nujxJ5pRCBOquFZaGn/p71Yr0oVitkttLKblFsqwa+10Lt6HBxm+2+VLp4Ja 0WZNncZciz3V3cuArpan/ZhhyiWYV5FD0pOXPCJIx7WS9PTtxiv0AOS4ScWEUmBxyhFeOpYa DrEx In-Reply-To: <20240930114045.76730-1-f.schauer@proxmox.com> X-SPAM-LEVEL: Spam detection results: 0 AWL -0.050 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment RCVD_IN_VALIDITY_CERTIFIED_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to Validity was blocked. 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SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pve-devel] applied: [PATCH v2 common] tools: file_set_contents: use syswrite instead of print X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox VE development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" Am 30/09/2024 um 13:40 schrieb Filip Schauer: > The use of `print` can be inefficient for writing larger files due to > its default buffering in 8 KiB blocks. > > This is especially problematic on `pmxcfs` where files are written in > 4 KiB blocks due to the defaults of `libfuse2`. This leads to > significant write amplification on files larger than 4 KiB. > > Patch (fix #5728: pmxcfs: allow bigger writes than 4k for fuse) [1] > addresses this by enabling `big_writes`, allowing up to 128 KiB blocks. > But due to the use of `print` in `file_set_contents`, writes are still > only buffered in 8 KiB blocks. > > To further address this, this commit switches to using `syswrite` > instead of `print` to mitigate the block size limit imposed by `print`. > Combined with patch [1], file writes to `/etc/pve/` are now buffered in > 128 KiB blocks. > > The table below illustrates the drastic reduction in write > amplification when writing files of different sizes to `/etc/pve/` using > `file_set_contents`: > > print big_writes+print big_writes+syswrite > file size written amplif. written amplif. written amplif. > 1 KiB 48 KiB 48.0 45 KiB 45.0 41 KiB 41.0 > 2 KiB 48 KiB 24.0 45 KiB 22.5 62 KiB 31.0 > 4 KiB 82 KiB 20.5 80 KiB 20.0 73 KiB 18.3 > 8 KiB 121 KiB 15.1 90 KiB 11.3 89 KiB 11.1 > 16 KiB 217 KiB 13.6 146 KiB 9.1 113 KiB 7.1 > 32 KiB 506 KiB 15.8 314 KiB 9.8 158 KiB 4.9 > 64 KiB 1472 KiB 23.0 826 KiB 12.9 259 KiB 4.0 > 128 KiB 5585 KiB 43.6 3765 KiB 29.4 452 KiB 3.5 > 256 KiB 20424 KiB 79.8 10743 KiB 42.0 2351 KiB 9.2 > 512 KiB 86715 KiB 169.4 43650 KiB 85.3 3204 KiB 6.3 > 1024 KiB 369568 KiB 360.9 187496 KiB 183.1 15845 KiB 15.5 > > Since `file_set_contents` also performs a `rename` after writing, the > following table shows the results when the file is written without > renaming it afterwards: > > print big_writes+print big_writes+syswrite > file size written amplif. written amplif. written amplif. > 1 KiB 29 KiB 29.0 29 KiB 29.0 25 KiB 25.0 > 2 KiB 29 KiB 14.5 30 KiB 15.0 25 KiB 12.5 > 4 KiB 37 KiB 9.3 44 KiB 11.0 41 KiB 10.3 > 8 KiB 61 KiB 7.6 45 KiB 5.6 45 KiB 5.6 > 16 KiB 143 KiB 8.9 86 KiB 5.4 57 KiB 3.6 > 32 KiB 396 KiB 12.4 225 KiB 7.0 69 KiB 2.2 > 64 KiB 1281 KiB 20.0 673 KiB 10.5 105 KiB 1.6 > 128 KiB 4789 KiB 37.4 3478 KiB 27.2 169 KiB 1.3 > 256 KiB 18868 KiB 73.7 9976 KiB 39.0 572 KiB 2.2 > 512 KiB 79304 KiB 154.9 42714 KiB 83.4 2150 KiB 4.2 > 1024 KiB 347929 KiB 339.8 182483 KiB 178.2 11133 KiB 10.9 > > [1] https://lists.proxmox.com/pipermail/pve-devel/2024-September/065396.html > > Signed-off-by: Filip Schauer > --- > Changes since v1: > * Add benchmark results without rename to commit message > * Fix "Wide character in syswrite" error by first encoding $data with print > > src/PVE/Tools.pm | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > > applied, and many thanks for the detailed benchmarks! _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel