From nobody Thu Nov 7 17:32:22 2024 X-Original-To: freebsd-net@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 4Xkq070VHpz5cFPJ for ; Thu, 07 Nov 2024 17:32:39 +0000 (UTC) (envelope-from gnn@neville-neil.com) Received: from relay1-d.mail.gandi.net (relay1-d.mail.gandi.net [217.70.183.193]) (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 4Xkq063mtmz4Rdm; Thu, 7 Nov 2024 17:32:38 +0000 (UTC) (envelope-from gnn@neville-neil.com) Authentication-Results: mx1.freebsd.org; none Received: by mail.gandi.net (Postfix) with ESMTPSA id CCF9A240004; Thu, 7 Nov 2024 17:32:31 +0000 (UTC) From: George Neville-Neil To: Andriy Gapon Cc: freebsd-net@freebsd.org Subject: Re: An interesting anomaly in NFS client... Date: Thu, 07 Nov 2024 09:32:22 -0800 X-Mailer: MailMate (1.14r5937) Message-ID: <0282629B-336F-46D4-8335-15F9BE8A7EE9@neville-neil.com> In-Reply-To: <8187509e-c9fb-403f-8569-28ba58425cff@FreeBSD.org> References: <7FFE3D2B-4DD9-4657-ADC1-9C40CB54991F@neville-neil.com> <8187509e-c9fb-403f-8569-28ba58425cff@FreeBSD.org> List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable X-GND-Sasl: gnn@neville-neil.com X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:29169, ipnet:217.70.176.0/20, country:FR] X-Rspamd-Queue-Id: 4Xkq063mtmz4Rdm X-Spamd-Bar: ---- On 6 Nov 2024, at 21:28, Andriy Gapon wrote: > On 07/11/2024 02:43, George Neville-Neil wrote: >> Howdy, >> >> We've been digging into an interesting possible issue in the FreeBSD N= FS client. Here is the scenario. I have a FreeBSD VM on my Mac, the Mac i= s the NFS server, the VM is the client. I then attempt to build an out of= tree kernel module that I'm working on. The build looks like it's hangin= g for 1.5 seconds, and when we look at the packets (pcap file attached) w= e see a ton of GETATTRs over the first 1.5 seconds. I've put the pcap up = here: oct_8_2024.pcapng >> >> I also note that an issue was raised on the forums that seems similar,= way back between FreeBSD 10 and 11: >> >> https://forums.freebsd.org/threads/nfs-cache-misses-after-upgrading-to= -11-1- from-10-3.65491/ >> >> I'm seeing this on 15 currentish (last few months). > > Could it be just make checking for stale targets? > I.e., stat-ing various files to check their timestamps. > 15,000 of them? Seems excessive for a kernel module of 10 files, but may= be it's walking /usr/obj ? Best, George