From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06F81C4332F for ; Tue, 1 Nov 2022 17:43:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230176AbiKARnr (ORCPT ); Tue, 1 Nov 2022 13:43:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229562AbiKARnl (ORCPT ); Tue, 1 Nov 2022 13:43:41 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB0AF1CB04 for ; Tue, 1 Nov 2022 10:42:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667324555; 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=SfX3RG8Twuc3X+jO0Ti+FSX1066Oauf6YVFak+lwBIQ=; b=LnKzdMy1KGKrTD+JHgQNDQ0etSG2DXyeRzkJkwh3aJ+ASWRs1fngalNHYCSiRaH88QpXx8 XrCi9sOY0wlYFS6zqOUP632b/iJ4ehl2T4bk8Ax2dn/y894fh9BCuq6vmEQKCj1JzeZG/j Efw2q3tHo8MCkZidBY9SZ/PppFGm9Fo= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-259-7QcEFs5CNU-CR68jW92niQ-1; Tue, 01 Nov 2022 13:42:32 -0400 X-MC-Unique: 7QcEFs5CNU-CR68jW92niQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A6B24382F652; Tue, 1 Nov 2022 17:42:31 +0000 (UTC) Received: from fuller.cnet (ovpn-112-2.gru2.redhat.com [10.97.112.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5537D40C94D1; Tue, 1 Nov 2022 17:42:31 +0000 (UTC) Received: by fuller.cnet (Postfix, from userid 1000) id 41228416CE48; Tue, 1 Nov 2022 14:35:45 -0300 (-03) Date: Tue, 1 Nov 2022 14:35:45 -0300 From: Marcelo Tosatti To: Leonardo =?iso-8859-1?Q?Br=E1s?= Cc: Steffen Klassert , Herbert Xu , "David S. Miller" , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/1] crypto/pcrypt: Do not use isolated CPUs for callback Message-ID: References: <20221004062536.280712-1-leobras@redhat.com> <3d6d47035f8897542a4786eef5a6b8885f4caaf0.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3d6d47035f8897542a4786eef5a6b8885f4caaf0.camel@redhat.com> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 11, 2022 at 03:20:39PM -0300, Leonardo Brás wrote: > On Fri, 2022-10-07 at 18:42 -0300, Leonardo Brás wrote: > > On Wed, 2022-10-05 at 09:57 -0300, Marcelo Tosatti wrote: > > > On Tue, Oct 04, 2022 at 03:25:37AM -0300, Leonardo Bras wrote: > > > > Currently pcrypt_aead_init_tfm() will pick callback cpus (ctx->cb_cpu) > > > > from any online cpus. Later padata_reorder() will queue_work_on() the > > > > chosen cb_cpu. > > > > > > > > This is undesired if the chosen cb_cpu is listed as isolated (i.e. using > > > > isolcpus=... kernel parameter), since the work queued will interfere with > > > > the workload on the isolated cpu. > > > > > > > > Make sure isolated cpus are not used for pcrypt. > > > > > > > > Signed-off-by: Leonardo Bras > > > > --- > > > > crypto/pcrypt.c | 10 +++++++--- > > > > 1 file changed, 7 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/crypto/pcrypt.c b/crypto/pcrypt.c > > > > index 9d10b846ccf73..9017d08c91a8d 100644 > > > > --- a/crypto/pcrypt.c > > > > +++ b/crypto/pcrypt.c > > > > @@ -16,6 +16,7 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > > > > > static struct padata_instance *pencrypt; > > > > static struct padata_instance *pdecrypt; > > > > @@ -175,13 +176,16 @@ static int pcrypt_aead_init_tfm(struct crypto_aead *tfm) > > > > struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst); > > > > struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm); > > > > struct crypto_aead *cipher; > > > > + struct cpumask non_isolated; > > > > + > > > > + cpumask_and(&non_isolated, cpu_online_mask, housekeeping_cpumask(HK_TYPE_DOMAIN)); > > > > > > Since certain systems do not use isolcpus=domain, so please use a flag > > > that is setup by nohz_full=, for example HK_FLAG_MISC: > > > > > > static int __init housekeeping_nohz_full_setup(char *str) > > > { > > > unsigned long flags; > > > > > > flags = HK_FLAG_TICK | HK_FLAG_WQ | HK_FLAG_TIMER | HK_FLAG_RCU | > > > HK_FLAG_MISC | HK_FLAG_KTHREAD; > > > > > > return housekeeping_setup(str, flags); > > > } > > > __setup("nohz_full=", housekeeping_nohz_full_setup); > > > > Oh, sure.  > > Since we are talking about WorkQueues, I think it makes sense to pick > > HK_FLAG_WQ. > > > > > > > > Also, shouldnt you use cpumask_t ?/ > > > > Yeah, I think so.  > > I was quick to choose the 'struct cpumask' because all functions would operate > > in this variable type, but yeah, I think it makes sense to have this variable > > being opaque here. > > In fact, it seems neither 'struct cpumask' nor 'cpumask_t' are recommended to be > used allocated in the stack, due to the large size it can get (up to 1kB).  > > At include/linux/cpumask.h we have: > 'cpumask_var_t: struct cpumask for stack usage' > which should work better at least for init functions like this. > > In other cases, I see 'static cpumask_t' being used to avoid the allocation > overhead, but it's probably due to the functions being called in very specific > scenarios. It could mean trouble if multiple cpus try to use it at once. > > What do you recommend on it? Sorry for the delay. I suppose allocating and freeing is OK in this context, since its initialization time and not a hot path?