From owner-freebsd-questions@freebsd.org Sun Nov 22 20:00:12 2020 Return-Path: Delivered-To: freebsd-questions@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 1703C472B4A for ; Sun, 22 Nov 2020 20:00:12 +0000 (UTC) (envelope-from lari.sihto@gmail.com) Received: from mail-lj1-x233.google.com (mail-lj1-x233.google.com [IPv6:2a00:1450:4864:20::233]) (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 4CfLjl2xktz3v2w for ; Sun, 22 Nov 2020 20:00:11 +0000 (UTC) (envelope-from lari.sihto@gmail.com) Received: by mail-lj1-x233.google.com with SMTP id i17so15764442ljd.3 for ; Sun, 22 Nov 2020 12:00:11 -0800 (PST) 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=+FNkj4NLNCefczInwKNX54nbmeYbvhVjezF6TSt/zVk=; b=bSE7nAt4FlIygCFuEWGB7mr61YUkScX/+/BihpGhGjyBDq9QY3Os1JqjLMAx31Tv3Y B0TgUn68byjgsNOOzVGOsAviZtU3wlNNZ0VMlRwoY7K6NlN8co/M/5bx6dT4dKJMlGE1 H3o69DonBTnUhd/msg31ye4eMQ9CEFguDCO346aNvJnvdh7AHn5X5RG4bHY+E8PsJv3p vwItiPTN5bmIhJ68RE/68qkkhDxSuJ07U9UnL/nKxwZ30F2jPomkotR40/J2x73xO+iZ l+yaVWiy6GSSOamvXbRo1L0/EXUeTMtvrVQY6qEIsgWU7ouNqhtMGPViRvYycFPHs4q8 /czA== 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=+FNkj4NLNCefczInwKNX54nbmeYbvhVjezF6TSt/zVk=; b=PiD3hnqf0/HKuZgHW6el/N/vIO5AK0ZY9U6WYiFMbdiAn8W+ECae/mI1Mdx2KtWqUh CAQ3pWjTRhNcwe3wcmxQNMSlRgyHF1VCQewSF29y/UpIFKnE4y+wlbnzI5JeJBtPCNFv PETSBRqnDC11dlI+OkXCkc/I/buAjtQ6WPDaxsO3quLET6vuhCNHQSIEz1qPyVhjl+mI hHt3h2qibX7E9JEU7u8CirR3JGfUqZhW3AKt2J3u0Pdl5GHGk5s7M90mCWSzI1ipUAx5 GCV7INC/FNg7ZfVGdC2yH8g4BrnFGi/uhDxAetFsSXnAC/0ZafODlwP2kW/97aykJ+ZJ MB8g== X-Gm-Message-State: AOAM533k0L8iQoOU/WXsf9W3pZXyRm6N2Pm7SpZTg1vyprERQx9jrSvd bJlxx1vKFxke6a59EZI81Rq3KRk60v7kucCFw588RNx4q+jDcA== X-Google-Smtp-Source: ABdhPJyW4ugk3IX8QglHQjEpP2hDFoJbnIeNhhOCypU9gVHEbunQgVBuWQ3jV9Vvf0zp8XOw/5wNUwv7IOD1/leVb7s= X-Received: by 2002:a2e:7306:: with SMTP id o6mr11179156ljc.306.1606075208864; Sun, 22 Nov 2020 12:00:08 -0800 (PST) MIME-Version: 1.0 From: Lari Sihto Date: Sun, 22 Nov 2020 21:59:57 +0200 Message-ID: Subject: kernel threads To: freebsd-questions@freebsd.org X-Rspamd-Queue-Id: 4CfLjl2xktz3v2w X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=gmail.com header.s=20161025 header.b=bSE7nAt4; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (mx1.freebsd.org: domain of larisihto@gmail.com designates 2a00:1450:4864:20::233 as permitted sender) smtp.mailfrom=larisihto@gmail.com X-Spamd-Result: default: False [-4.00 / 15.00]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36:c]; FREEMAIL_FROM(0.00)[gmail.com]; TO_DN_NONE(0.00)[]; DKIM_TRACE(0.00)[gmail.com:+]; DMARC_POLICY_ALLOW(-0.50)[gmail.com,none]; NEURAL_HAM_SHORT(-1.00)[-1.000]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RBL_DBL_DONT_QUERY_IPS(0.00)[2a00:1450:4864:20::233:from]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; TAGGED_FROM(0.00)[]; DWL_DNSWL_NONE(0.00)[gmail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[gmail.com:s=20161025]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; SPAMHAUS_ZRD(0.00)[2a00:1450:4864:20::233:from:127.0.2.255]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::233:from]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-questions] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 22 Nov 2020 20:00:12 -0000 Hi, just wondering if there is some technical or philosophical reason as to why the freebsd operating system doesn't seem to use kernel-space threads like some other unix-like operating systems do. To my knowledge the need for kernel threads arises when the kernel code needs to sleep in kernel which one cannot do. Kernel threads seem to fix that problem. Have been wondering this for a long time and I hope someone here knows the reasoning behind this implementation detail be it just performance related or something along the line of "no-one just haven't been up to implementing that kind of a functionality"? Thanks