From owner-freebsd-arch@freebsd.org Mon Oct 26 14:20:44 2020 Return-Path: Delivered-To: freebsd-arch@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 C8EF34466E3 for ; Mon, 26 Oct 2020 14:20:44 +0000 (UTC) (envelope-from number201724@me.com) Received: from pv50p00im-tydg10011801.me.com (pv50p00im-tydg10011801.me.com [17.58.6.52]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4CKcSX0rDDz4Jym for ; Mon, 26 Oct 2020 14:20:43 +0000 (UTC) (envelope-from number201724@me.com) Received: from [10.0.0.4] (unknown [213.173.32.131]) by pv50p00im-tydg10011801.me.com (Postfix) with ESMTPSA id 9654D660362 for ; Mon, 26 Oct 2020 14:20:36 +0000 (UTC) Subject: Re: C1's latency is still way too high for our latency-sensitive deployment To: freebsd-arch@freebsd.org References: <7fc9ff47-03ad-d4e1-f499-75aef3ef56d9@me.com> <20201026135549.GN2643@kib.kiev.ua> From: YUAN RUI Message-ID: <8b583031-16bf-da29-8511-c3100ab36e44@me.com> Date: Mon, 26 Oct 2020 22:20:33 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: <20201026135549.GN2643@kib.kiev.ua> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.737 definitions=2020-10-26_06:2020-10-26, 2020-10-26 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 mlxscore=0 mlxlogscore=694 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-2006250000 definitions=main-2010260104 X-Rspamd-Queue-Id: 4CKcSX0rDDz4Jym X-Spamd-Bar: ---- X-Spamd-Result: default: False [-4.38 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; RWL_MAILSPIKE_GOOD(0.00)[17.58.6.52:from]; R_SPF_ALLOW(-0.20)[+ip4:17.58.0.0/16:c]; FREEMAIL_FROM(0.00)[me.com]; TO_DN_NONE(0.00)[]; DKIM_TRACE(0.00)[me.com:+]; DMARC_POLICY_ALLOW(-0.50)[me.com,quarantine]; NEURAL_HAM_SHORT(-0.37)[-0.371]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[me.com]; ASN(0.00)[asn:714, ipnet:17.58.0.0/20, country:US]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.02)[-1.016]; R_DKIM_ALLOW(-0.20)[me.com:s=1a1hai]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.00)[-0.997]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-arch@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; DWL_DNSWL_LOW(-1.00)[me.com:dkim]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-arch] X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Oct 2020 14:20:44 -0000 It looks like I didn't find the document. The problem is solved. On 10/26/2020 9:55 PM, Konstantin Belousov wrote: > On Mon, Oct 26, 2020 at 09:29:02PM +0800, YUAN RUI via freebsd-arch wrote: >> C1's latency is still way too high for our latency-sensitive deployment >> I want a generic interface that allows applications to prevent entering deep >> C-state >> >> >> Similar: >> >> linux api:https://access.redhat.com/articles/65410 > So what do you want that we do not provide ? > There is cpu idle spin method that you can switch to, using > machdep.idle sysctl. > >> windows api:https://docs.microsoft.com/en-us/windows/win32/api/timeapi/nf-timeapi-timebeginperiod >> > There is no mention that windows HALs tie timer precision with Cx latency. > That said, FreeBSD has a knob kern.timecounter.alloweddeviation, that specifies > how much precision is taken when setting up process timers or when sleeping > by explicit user request. > >> In fact, a better way is to provide windows to applications in the form of >> APIs, But Linux can be fine-tuned. >> >> _______________________________________________ >> freebsd-arch@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-arch >> To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" > _______________________________________________ > freebsd-arch@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org"