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 4A4B62E1C61; Thu, 21 Aug 2025 19:51:35 +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=1755805899; cv=none; b=oFj4TLyojEbGi/UnAxWdpRobojnnQgA3a9WwMN2pQyYegStLTOdDdSQirm500OwO8G9hcbuwXsSEpREdCskU7DJbYqpLzM6dpoUT2ht7BDQJQhiWQ5fJet9OQbtyKhXBE2RKAvKS2NE8dUXhtDZekDu4uu+ntrZkpGY6XNSBXGA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755805899; c=relaxed/simple; bh=30mBFZ4JYj9b21LFAPp5gU+bfjU81MgNEV8IwqGszc0=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=lrMoiLdB8RlifVJycCElJ9d8YCnnekJtsxgDY426IXQuamPrRbpqnYpForqKVTlZRNtsIHHfu1Wtwo6piADSx17lxKRm4HLkLrolQ3X9Cjr1MAs4lH04l1P07GiDyxYiMTQx2JQMRw59rRXXDLTrY6YU/RiYh+Qvmu89yNvFY5k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iSzuI+iJ; 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="iSzuI+iJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B612C4CEEB; Thu, 21 Aug 2025 19:51:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755805895; bh=30mBFZ4JYj9b21LFAPp5gU+bfjU81MgNEV8IwqGszc0=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=iSzuI+iJcNno+CxpOKv3JecJ1oNvkrc+a/T2nX5YCEwIsNRYvUkO2VI/wkY26VWYu 7IbLQfXmiqOYdWCB2MepJyqZrjEQRb+ma4+luPYPtKt5rPCHRjjLABvXLt1S5A+Pir ZTJr1OWmsGBa3N3HwBOf7wd/odDrDRQTA4W+jPb/A9tXk21GGGIbH2vnVIX1WVPBg9 W9yaesfMsmxPh1pCRDlRFfmEmoz70eMI/+un/sWvGMvzxEju93NcUW/mkJZL4I022j ZLma40ofk3tOuozAt1TRk2PdNHo0vLNwOensVKznSEeM0AavgTgvL9P2tCi5bhuid3 MUh8s8SodwChg== Message-ID: <3bbe56ff1312c5afbdbe3de91c0ddb57d836f30f.camel@kernel.org> Subject: Re: [PATCH 2/2] sunrpc: add a Kconfig option to redirect dfprintk() output to trace buffer From: Jeff Layton To: Anna Schumaker , Trond Myklebust , Anna Schumaker , Chuck Lever , NeilBrown , Olga Kornievskaia , Dai Ngo , Tom Talpey , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Date: Thu, 21 Aug 2025 15:51:33 -0400 In-Reply-To: References: <20250821-nfs-testing-v1-0-f06099963eda@kernel.org> <20250821-nfs-testing-v1-2-f06099963eda@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn VluJH0/RcxEeFbnSaswVChNSGa7mXJrTR22lRL6ZPjdMgS2Km90haWPRc8Wolcz07Y2se0xpGVLEQ 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CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.56.2 (3.56.2-1.fc42) Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2025-08-21 at 15:44 -0400, Anna Schumaker wrote: > Hi Jeff, >=20 > On 8/21/25 1:16 PM, Jeff Layton wrote: > > We have a lot of old dprintk() call sites that aren't going anywhere > > anytime soon. At the same time, turning them up is a serious burden on > > the host due to the console locking overhead. > >=20 > > Add a new Kconfig option that redirects dfprintk() output to the trace > > buffer. This is more efficient than logging to the console and allows > > for proper interleaving of dprintk and static tracepoint events. > >=20 > > Since using trace_printk() causes scary warnings to pop at boot time, > > this new option defaults to "n". > >=20 > > Signed-off-by: Jeff Layton > > --- > > include/linux/sunrpc/debug.h | 10 ++++++++-- > > net/sunrpc/Kconfig | 14 ++++++++++++++ > > 2 files changed, 22 insertions(+), 2 deletions(-) > >=20 > > diff --git a/include/linux/sunrpc/debug.h b/include/linux/sunrpc/debug.= h > > index 99a6fa4a1d6af0b275546a53957f07c9a509f2ac..fd9f79fa534ef001b3ec5e6= d7e4b1099843b64a4 100644 > > --- a/include/linux/sunrpc/debug.h > > +++ b/include/linux/sunrpc/debug.h > > @@ -30,17 +30,23 @@ extern unsigned int nlm_debug; > > #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) > > # define ifdebug(fac) if (unlikely(rpc_debug & RPCDBG_##fac)) > > =20 > > +# if IS_ENABLED(CONFIG_SUNRPC_DEBUG_TRACE) > > +# define __sunrpc_printk(fmt, ...) trace_printk(fmt, ##__VA_ARGS__) > > +# else > > +# define __sunrpc_printk(fmt, ...) pr_default(fmt, ##__VA_ARGS__) >=20 > This is the only reference I can find to "pr_default()" in my tree, and m= y compiler isn't > very happy about it. Am I missing a patch somewhere? >=20 > Thanks, > Anna >=20 No, my apologies. I had made a change in my test branch and didn't pick it back into my send branch. That should be: # define __sunrpc_printk(fmt, ...) printk(KERN_DEFAULT fmt, ##__VA_ARGS__) I can resend if you are amenable to this patch. > > +# endif > > + > > # define dfprintk(fac, fmt, ...) \ > > do { \ > > ifdebug(fac) \ > > - printk(KERN_DEFAULT fmt, ##__VA_ARGS__); \ > > + __sunrpc_printk(fmt, ##__VA_ARGS__); \ > > } while (0) > > =20 > > # define dfprintk_rcu(fac, fmt, ...) \ > > do { \ > > ifdebug(fac) { \ > > rcu_read_lock(); \ > > - printk(KERN_DEFAULT fmt, ##__VA_ARGS__); \ > > + __sunrpc_printk(fmt, ##__VA_ARGS__); \ > > rcu_read_unlock(); \ > > } \ > > } while (0) > > diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig > > index 2d8b67dac7b5b58a8a86c3022dd573746fb22547..a570e7adf270fb8976f7512= 66bbffe39ef696c6a 100644 > > --- a/net/sunrpc/Kconfig > > +++ b/net/sunrpc/Kconfig > > @@ -101,6 +101,20 @@ config SUNRPC_DEBUG > > =20 > > If unsure, say Y. > > =20 > > +config SUNRPC_DEBUG_TRACE > > + bool "RPC: Send dfprintk() output to the trace buffer" > > + depends on SUNRPC_DEBUG && TRACING > > + default n > > + help > > + dprintk() output can be voluminous, which can overwhelm the > > + kernel's logging facility as it must be sent to the console. > > + This option causes dprintk() output to go to the trace buffe= r > > + instead of the kernel log. > > + > > + This will cause warnings about trace_printk() being used to = be > > + logged at boot time, so say N unless you are debugging a pro= blem > > + with sunrpc-based clients or services. > > + > > config SUNRPC_XPRT_RDMA > > tristate "RPC-over-RDMA transport" > > depends on SUNRPC && INFINIBAND && INFINIBAND_ADDR_TRANS > >=20 --=20 Jeff Layton