From nobody Thu May 5 07:11:08 2022 X-Original-To: arch@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 78B8E1AB950D for ; Thu, 5 May 2022 07:11:16 +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 4Kv4cM6Tknz3FP8; Thu, 5 May 2022 07:11:12 +0000 (UTC) (envelope-from hps@selasky.org) Received: from [10.36.2.165] (unknown [176.74.213.87]) (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 A900826021A; Thu, 5 May 2022 09:11:11 +0200 (CEST) Message-ID: <04f80ff1-2374-8f49-ac13-1c55570cb6c0@selasky.org> Date: Thu, 5 May 2022 09:11:08 +0200 List-Id: Discussion related to FreeBSD architecture List-Archive: https://lists.freebsd.org/archives/freebsd-arch List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arch@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: Time sharing for interrupt threads Content-Language: en-US To: John Baldwin , arch@FreeBSD.org Cc: gallatin@FreeBSD.org References: From: Hans Petter Selasky In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4Kv4cM6Tknz3FP8 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of hps@selasky.org designates 88.99.82.50 as permitted sender) smtp.mailfrom=hps@selasky.org X-Spamd-Result: default: False [-2.97 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+a:mail.turbocat.net:c]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[selasky.org]; NEURAL_HAM_LONG(-1.00)[-1.000]; TO_DN_SOME(0.00)[]; NEURAL_HAM_MEDIUM(-0.68)[-0.676]; NEURAL_HAM_SHORT(-1.00)[-0.995]; MLMMJ_DEST(0.00)[arch]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:88.99.0.0/16, country:DE]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] X-ThisMailContainsUnwantedMimeParts: N On 5/4/22 23:48, John Baldwin wrote: > My recent changes to the softclock threads (raising their priority) were to > address a livelock issue in which a constant stream of packets could starve > timeout events. Sorry for short-cutting the thread, but why can't we have multiple worker threads with different prio's for timers? In USB we have that, once for Giant locked and non-Giant locked callbacks. I mean, all timer interrupts are executed serially and any congested mutex will make all succeeding timer callbacks halt on that CPU core! --HPS