From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1BB81DB958 for ; Fri, 21 Feb 2025 15:46:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740152793; cv=none; b=hG9D4nUOf+WA51mNpugH8JCFqxPv1CAMG95vBT0sFoQmfGSv+pQGJhLd2OPNlfpRiQxnyZ5qugBaWLSPx8ZbJeYOHDpE4hGJsZwAXzZcJRgoPAF+3elMxbdcwjisDeghmj2xOiHenh94thDO9K8L+eNOEf7xWfOP/B/IfCU28qE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740152793; c=relaxed/simple; bh=hJK3sx8QpE4Z2mmbD7JIhcYZcECkqlCej0Dc8JgfJ3E=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=D+hZVPmhaiOVVDe/8HpggIpeL3tAB3lQQOb1THUj1Afvva8Qbm9etZPG16iXTwNV3trJANNDDvlgo/nAphroESAw8E1+wl0eF66q/b33jFSmrftM2om8aggE2GkTpaiPh67T+LAbvoH/GyISgcvpzGAkVKwF8o/brjPTGTa2gvI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DaTYaqle; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DaTYaqle" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BA877C4CED6; Fri, 21 Feb 2025 15:46:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740152792; bh=hJK3sx8QpE4Z2mmbD7JIhcYZcECkqlCej0Dc8JgfJ3E=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=DaTYaqlemBGW221JtvRKDc7jz+EBzcJ4qp2aqeaFM2yDRwn0blFEP1kBOJM33Uffp TI4N5OzhST0tBa1RqgeIK6U8jt250RKtVjNyPdL6jMf7cfRKXW64nR+zPbHpaTw77q j6Tq3sY45IbsxUMu2cI+UKlzPL+foi78inm2GzP1vV8JMKqgh1fK02TbLU6bfBA/yW EQMjJV3N7Kjs5czKaXhlGRQL3pczxXF9gXPI45Z2JE++sBQo4JavRRbdYZkIiaaek/ va1yuUscivYIF2+imlSXejM93PCfZSEWwqTJ+T3bzbdagUUvySO08LGCBQAUnbhAsA ioJx8ZIDbwOfw== Message-ID: Subject: Re: nfsd: add the ability to enable use of RWF_DONTCACHE for all nfsd IO From: Jeff Layton To: Chuck Lever , Mike Snitzer Cc: linux-nfs@vger.kernel.org, Neil Brown , Olga Kornievskaia , Dai Ngo , Tom Talpey , axboe@kernel.dk Date: Fri, 21 Feb 2025 10:46:30 -0500 In-Reply-To: <64d7e00d-e025-481a-9145-7038e9ee7fdf@oracle.com> References: <20250220171205.12092-1-snitzer@kernel.org> <64d7e00d-e025-481a-9145-7038e9ee7fdf@oracle.com> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 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Snitzer wrote: > > On Thu, Feb 20, 2025 at 01:17:42PM -0500, Chuck Lever wrote: > > > * It might be argued that putting these experimental tunables under /= sys > > > eliminates the support longevity question, since there aren't stric= t > > > rules about removing files under /sys. > >=20 > > Right, I do think a sysfs knob (that defaults to disabled, requires > > user opt-in) is a pretty useful and benign means to expose > > experimental functionality. >=20 > Seems like we want to figure out a blessed way to add this kind of > experimental "hidden" tunable in a way that can be easily removed > once we have the answers we need. >=20 > I'd really like to keep the documented administrative interface as > straightforward as possible, but I agree that having a way to > experiment is valuable. >=20 We do have this fancy new netlink interface that is extensible. You could extend the "threads" call to add a server-wide boolean for this and then extend nfsdctl to set that value in some cases. --=20 Jeff Layton