From owner-freebsd-hackers@freebsd.org Tue Aug 25 20:02:31 2020 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 760E83B92EE; Tue, 25 Aug 2020 20:02:31 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-ed1-x52d.google.com (mail-ed1-x52d.google.com [IPv6:2a00:1450:4864:20::52d]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BbfzV3WN8z42p2; Tue, 25 Aug 2020 20:02:30 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: by mail-ed1-x52d.google.com with SMTP id b2so12371098edw.5; Tue, 25 Aug 2020 13:02:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=n7+3YVjO1Khzh+V316JgdFE82RCQMoHlp3StPrR87VE=; b=V8ygSlWiLqlwfSaO4cSqVJbz4Vo/m6dy8iP+YGJYF7fgD/oNlY8U+tk8KlC8Gh0sdd KokTohhtXQX0Cyo+HA95oFzSrb0mBDGTDernEv0+1DRDPSUs7brECyB6Lzxe/BNUb8LE VWVlwifjRRAxEPnqcqkftGLrZnXiXnzw6eNoK0YzwcMT0r0jX39vP5dYfmwY2geCvTwG zGaGDv5w2tuz9Id3ZnZgBZIIkdwH2UdT699xAgX2JrkxqRoAYIonJP8sfPOeGQ4iHgrB u3bZm6W1xjZVI+45d+KpL/B6cDPurtUUubclNXyC48ew+3KZWtclG179hAbjQfhu6i4m MFeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=n7+3YVjO1Khzh+V316JgdFE82RCQMoHlp3StPrR87VE=; b=Ciscpfq0ekpoq/EC+tYLnmMmeQbYerP+sqJyRJ+HdqSXGnwF95tUtAaCogw6Yz4Uk9 +dWc82W2YKWfrJ+F/k8acgls1M/zl4soSHLdZAnkPzfxigW3bB7TlVyysnBMy4aRge8H 22XwR6eqqujsbnp/KfPnvZkWGg6Myuy8sJwdt/5wfc5sNTh5gvmUauh7m13LrjgGKiFw 3ASM/vbKH25SXb+x6Cz2Q90kYXUJKWJcxsO01M/g5DfgegPhxwlXAP3M2bocFIAnUjZ9 uqGtfegDNQJDfYl5fjSkXVo77iHEsSHZJcEOWiXHCuSr0eArI06k2o1UETsWM4Yf0Lqa nuMQ== X-Gm-Message-State: AOAM533SpNjUyqgFc2k5j9rHYagoKtPFuOysrAyBXVBfyBysa9vKB9SB hw9ew9cpBabZc0AAuMVuI28k9kLnWPzlLNbfpFVFqFU= X-Google-Smtp-Source: ABdhPJwCE73KA1u8kN+v1Ph4Ym4Wt+Y35NNUDJSo9OdgwxajlvsUMjOMcNjluFKHP8GuA7UsTSXjrtIixbJSKnJjn/8= X-Received: by 2002:a05:6402:306f:: with SMTP id bs15mr11595419edb.249.1598385748689; Tue, 25 Aug 2020 13:02:28 -0700 (PDT) MIME-Version: 1.0 From: Zaphod Beeblebrox Date: Tue, 25 Aug 2020 16:02:15 -0400 Message-ID: Subject: Boot time TRIM ? To: freebsd-fs , FreeBSD Hackers X-Rspamd-Queue-Id: 4BbfzV3WN8z42p2 X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=V8ygSlWi; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of zbeeble@gmail.com designates 2a00:1450:4864:20::52d as permitted sender) smtp.mailfrom=zbeeble@gmail.com X-Spamd-Result: default: False [-1.48 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.74)[-0.743]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; RCVD_TLS_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_ALL(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; RCPT_COUNT_TWO(0.00)[2]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::52d:from]; NEURAL_HAM_SHORT(-0.74)[-0.736]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; SUBJECT_ENDS_QUESTION(1.00)[]; MAILMAN_DEST(0.00)[freebsd-fs,freebsd-hackers]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.33 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 25 Aug 2020 20:02:31 -0000 So, as I was looking at the performance of an NVME that I use for swap and ZFS cache, I realized after reboot, that since ZFS cache doesn't survive reboot and OBVIOUSLY swap doesn't, might it be best practice to issue a TRIM on boot? Now... a trim on the whole device from userland before adding swap in RC... might work. AFAIK, we still don't have any structure to swap before it's added. I'm pretty sure this is not the right thing for ZFS cache and log partitions, tho. Also, as a point of information, does ZFS issue TRIMs to the LOG after data gets committed into a transaction? I'm curious about this because for NVME that are a hybrid of different storage --- commonly 10-20 percent faster MLC and 80 percent slower TLC (or what-have-you) ... the TRIM usage can dramatically affect the performance.