From nobody Mon Aug 21 06:19:28 2023 X-Original-To: current@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 4RTj4Z09RNz4qHJW for ; Mon, 21 Aug 2023 06:19:42 +0000 (UTC) (envelope-from Alexander@Leidinger.net) Received: from mailgate.Leidinger.net (bastille.leidinger.net [89.238.82.207]) (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-signature ECDSA (P-256) client-digest SHA256) (Client CN "mailgate.leidinger.net", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4RTj4Y4Cpbz3KRZ for ; Mon, 21 Aug 2023 06:19:41 +0000 (UTC) (envelope-from Alexander@Leidinger.net) Authentication-Results: mx1.freebsd.org; none Received: from webmail2.leidinger.net (roundcube.Leidinger.net [192.168.1.123]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: Alexander@Leidinger.net) by outgoing.leidinger.net (Postfix) with ESMTPSA id EE305482; Mon, 21 Aug 2023 08:19:28 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=leidinger.net; s=outgoing-alex; t=1692598772; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=l2CLNhO1fMwXtWngLhUeZQpgrbYDp2FSJ7OxNqnXa9c=; b=Hjo/Cp4mxgnTSCBPhNR4TiLE3exznGmL35GRYGD/p9wTcbjVIaxI9fIW/64STNpYyWRx6X DP5fqZ2DumaZUYyeL1gRXM2bYrg3IDKDoBDjZCJdn1ETx20t3Y2o8qqvIc66VKeibdrhLl zw6ORs7qM4XX2IoXBndQz3Pfb+JJaNKxgdi1NlAzcLE1+u7VRQbEl9W6DxKjmkQ6dHiEfF zguGGtBpC2gB5uoKR21xIXHtlbBDD8RZKa97Iyd5t3+RBNU8GLlEeqXXLUWSePLHHfauOy ef6gfvQpP7oXzPlBOGWa9TXufKcUkDgmp/P6xNpPqxe6dRiAOiHwQ+bwcEwHYg== List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@freebsd.org MIME-Version: 1.0 Date: Mon, 21 Aug 2023 08:19:28 +0200 From: Alexander Leidinger To: Konstantin Belousov Cc: Mateusz Guzik , current@freebsd.org Subject: Re: Speed improvements in ZFS In-Reply-To: References: <88e837aeb5a65c1f001de2077fb7bcbd@Leidinger.net> <4d60bd12b482e020fd4b186a9ec1a250@Leidinger.net> <73f7c9d3db8f117deb077fb17b1e352a@Leidinger.net> <58493b568dbe9fb52cc55de86e01f5e2@Leidinger.net> Message-ID: <58ac6211235c52d744666e8ae2ec7568@Leidinger.net> X-Sender: Alexander@Leidinger.net Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4RTj4Y4Cpbz3KRZ X-Spamd-Bar: ---- 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:34240, ipnet:89.238.64.0/18, country:DE] Am 2023-08-20 23:17, schrieb Konstantin Belousov: > On Sun, Aug 20, 2023 at 11:07:08PM +0200, Mateusz Guzik wrote: >> On 8/20/23, Alexander Leidinger wrote: >> > Am 2023-08-20 22:02, schrieb Mateusz Guzik: >> >> On 8/20/23, Alexander Leidinger wrote: >> >>> Am 2023-08-20 19:10, schrieb Mateusz Guzik: >> >>>> On 8/18/23, Alexander Leidinger wrote: >> >>> >> >>>>> I have a 51MB text file, compressed to about 1MB. Are you interested >> >>>>> to >> >>>>> get it? >> >>>>> >> >>>> >> >>>> Your problem is not the vnode limit, but nullfs. >> >>>> >> >>>> https://people.freebsd.org/~mjg/netchild-periodic-find.svg >> >>> >> >>> 122 nullfs mounts on this system. And every jail I setup has several >> >>> null mounts. One basesystem mounted into every jail, and then shared >> >>> ports (packages/distfiles/ccache) across all of them. >> >>> >> >>>> First, some of the contention is notorious VI_LOCK in order to do >> >>>> anything. >> >>>> >> >>>> But more importantly the mind-boggling off-cpu time comes from >> >>>> exclusive locking which should not be there to begin with -- as in >> >>>> that xlock in stat should be a slock. >> >>>> >> >>>> Maybe I'm going to look into it later. >> >>> >> >>> That would be fantastic. >> >>> >> >> >> >> I did a quick test, things are shared locked as expected. >> >> >> >> However, I found the following: >> >> if ((xmp->nullm_flags & NULLM_CACHE) != 0) { >> >> mp->mnt_kern_flag |= >> >> lowerrootvp->v_mount->mnt_kern_flag & >> >> (MNTK_SHARED_WRITES | MNTK_LOOKUP_SHARED | >> >> MNTK_EXTENDED_SHARED); >> >> } >> >> >> >> are you using the "nocache" option? it has a side effect of xlocking >> > >> > I use noatime, noexec, nosuid, nfsv4acls. I do NOT use nocache. >> > >> >> If you don't have "nocache" on null mounts, then I don't see how this >> could happen. > > There is also MNTK_NULL_NOCACHE on lower fs, which is currently set for > fuse and nfs at least. 11 of those 122 nullfs mounts are ZFS datasets which are also NFS exported. 6 of those nullfs mounts are also exported via Samba. The NFS exports shouldn't be needed anymore, I will remove them. Shouldn't this implicit nocache propagate to the mount of the upper fs to give the user feedback about the effective state? Bye, Alexander. -- http://www.Leidinger.net Alexander@Leidinger.net: PGP 0x8F31830F9F2772BF http://www.FreeBSD.org netchild@FreeBSD.org : PGP 0x8F31830F9F2772BF