From owner-dev-commits-src-all@freebsd.org Thu Mar 11 18:42:12 2021 Return-Path: Delivered-To: dev-commits-src-all@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 28CBF5A9BC0; Thu, 11 Mar 2021 18:42:12 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4DxHqS01w3z3kD4; Thu, 11 Mar 2021 18:42:11 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2020.home.selasky.org (unknown [178.17.145.105]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 3646B260243; Thu, 11 Mar 2021 19:42:10 +0100 (CET) Subject: Re: git: d1cbe7908986 - main - Allocating the LinuxKPI current structure from an interrupt thread must be done using the M_NOWAIT flag after 1ae20f7c70ea . To: Konstantin Belousov Cc: John Baldwin , src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org References: <202103100952.12A9qRKR040117@gitrepo.freebsd.org> <2b1739ab-000c-ca28-5a59-0a3e19ef4591@selasky.org> <5aaa5f2a-a67d-a495-7f56-a6b31c2494c7@FreeBSD.org> From: Hans Petter Selasky Message-ID: <3dcd63b0-fe90-2855-f349-2117ca4b6b26@selasky.org> Date: Thu, 11 Mar 2021 19:41:53 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4DxHqS01w3z3kD4 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Mar 2021 18:42:12 -0000 On 3/11/21 7:35 PM, Konstantin Belousov wrote: > And I dislike this. It is yet another case of introducing consumer-specific > logic into core. Isn't netepoch example enough? > > I presented another patch to Hans, where task and mm allocations are > switched to zones, and the zones have reserve applied. Then allocations > from ithreads use the reserve. > > There is one detail there, reserve is finite, for x86 I set it to the > total limit of interrupts. This somewhat breaks if interrupts are > deallocated and reallocated, but I think it is good enough even with > this wart. Hi, Your patch doesn't address the issue of initializing the pointers in question once. Still, for every call, we need to check if the pointer is valid. This is not neccessary. Also I don't see why we need to create a own UMA zone for these simple structures. Won't the per-CPU sysctl consume more memory than the actual task structures being allocated? --HPS