Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 20 Apr 2023 11:59:13 +0300 (EEST)
From:   =?ISO-8859-15?Q?Ilpo_J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>
To:     "Moger, Babu" <babu.moger@amd.com>
cc:     corbet@lwn.net, Reinette Chatre <reinette.chatre@intel.com>,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        fenghua.yu@intel.com, dave.hansen@linux.intel.com, x86@kernel.org,
        hpa@zytor.com, paulmck@kernel.org, akpm@linux-foundation.org,
        quic_neeraju@quicinc.com, rdunlap@infradead.org,
        damien.lemoal@opensource.wdc.com, songmuchun@bytedance.com,
        peterz@infradead.org, jpoimboe@kernel.org, pbonzini@redhat.com,
        chang.seok.bae@intel.com, pawan.kumar.gupta@linux.intel.com,
        jmattson@google.com, daniel.sneddon@linux.intel.com,
        sandipan.das@amd.com, tony.luck@intel.com, james.morse@arm.com,
        linux-doc@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
        bagasdotme@gmail.com, eranian@google.com,
        christophe.leroy@csgroup.eu, jarkko@kernel.org,
        adrian.hunter@intel.com, quic_jiles@quicinc.com,
        peternewman@google.com
Subject: Re: [PATCH v4 7/7] x86/resctrl: Add debug files when mounted with
 debug option
In-Reply-To: <933d8ae2-d8b7-7436-5918-f639405c9ecb@amd.com>
Message-ID: <346622f4-3ea9-c19c-6175-3346ffc6016@linux.intel.com>
References: <168177435378.1758847.8317743523931859131.stgit@bmoger-ubuntu> <168177451010.1758847.568218491528297451.stgit@bmoger-ubuntu> <56497126-8f60-e590-bb13-b3739114375@linux.intel.com> <933d8ae2-d8b7-7436-5918-f639405c9ecb@amd.com>
MIME-Version: 1.0
Content-Type: multipart/mixed; BOUNDARY="8323329-353585656-1681981002=:2051"
Content-ID: <60e2175a-39f2-8ea0-1482-debe437a1fb9@linux.intel.com>
Precedence: bulk

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.

--8323329-353585656-1681981002=:2051
Content-Type: text/plain; CHARSET=ISO-8859-15
Content-Transfer-Encoding: 8BIT
Content-ID: <ae2428aa-843f-4ba1-4343-d66a1e4ba57e@linux.intel.com>

On Wed, 19 Apr 2023, Moger, Babu wrote:

> 
> 
> On 4/19/23 08:20, Ilpo J?rvinen wrote:
> > On Mon, 17 Apr 2023, Babu Moger wrote:
> > 
> >> Add the debug files to the resctrl hierarchy.
> >>
> >> Signed-off-by: Babu Moger <babu.moger@amd.com>
> >> ---
> >>  arch/x86/kernel/cpu/resctrl/internal.h |    1 +
> >>  arch/x86/kernel/cpu/resctrl/rdtgroup.c |   54 +++++++++++++++++++++++++++++++-
> >>  2 files changed, 54 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> >> index 1eac07ebc31b..855109abb480 100644
> >> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> >> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> >> @@ -288,6 +288,7 @@ struct rdtgroup {
> >>  #define RFTYPE_TOP			BIT(4)
> >>  #define RFTYPE_RES_CACHE		BIT(5)
> >>  #define RFTYPE_RES_MB			BIT(6)
> >> +#define RFTYPE_DEBUG			BIT(7)
> >>  #define RFTYPE_CTRL_INFO		(RFTYPE_INFO | RFTYPE_CTRL)
> >>  #define RFTYPE_MON_INFO			(RFTYPE_INFO | RFTYPE_MON)
> >>  #define RFTYPE_TOP_INFO			(RFTYPE_INFO | RFTYPE_TOP)
> >> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> >> index 15ded0dd5b09..1ec4359348c2 100644
> >> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> >> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> >> @@ -1880,6 +1880,7 @@ static struct rftype res_common_files[] = {
> >>  		.mode		= 0444,
> >>  		.kf_ops		= &rdtgroup_kf_single_ops,
> >>  		.seq_show	= rdtgroup_rmid_show,
> >> +		.fflags		= RFTYPE_BASE | RFTYPE_DEBUG,
> >>  	},
> >>  	{
> >>  		.name		= "schemata",
> >> @@ -1909,6 +1910,7 @@ static struct rftype res_common_files[] = {
> >>  		.mode		= 0444,
> >>  		.kf_ops		= &rdtgroup_kf_single_ops,
> >>  		.seq_show	= rdtgroup_closid_show,
> >> +		.fflags		= RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
> >>  	},
> >>  
> >>  };
> >> @@ -2420,6 +2422,49 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
> >>  			     struct rdtgroup *prgrp,
> >>  			     struct kernfs_node **mon_data_kn);
> >>  
> >> +static void resctrl_add_debug_files(void)
> >> +{
> >> +	struct rftype *rfts, *rft;
> >> +	int len;
> >> +
> >> +	rfts = res_common_files;
> >> +	len = ARRAY_SIZE(res_common_files);
> >> +
> >> +	lockdep_assert_held(&rdtgroup_mutex);
> >> +
> >> +	for (rft = rfts; rft < rfts + len; rft++) {
> >> +		if (rft->fflags & RFTYPE_DEBUG) {
> >> +			rft->fflags &= ~RFTYPE_DEBUG;
> > 
> > I don't fully follow why you need to play with ->fflags like this.
> > 
> > Is it for the ->fflags test in rdtgroup_add_files()? Can't you just do 
> > some extra masking there for RFTYPE_DEBUG based on resctrl_debug which 
> > you already keep?
> 
> Actually with this change, I can remove all these tricks here.
> I don't have to change the check "if (rft->fflags && ((fflags &
> rft->fflags) == rft->fflags)) {"
> 
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 1ec4359348c2..b560c44817bb 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -1925,6 +1925,9 @@ static int rdtgroup_add_files(struct kernfs_node
> *kn, unsigned long fflags)
> 
>         lockdep_assert_held(&rdtgroup_mutex);
> 
> +       if (resctrl_debug)
> +               fflags |= RFTYPE_DEBUG;

Yes, looks good.

It matches to the idea I had in my mind but doesn't require putting it 
into the if condition itself.

> +
>         for (rft = rfts; rft < rfts + len; rft++) {
>                 if (rft->fflags && ((fflags & rft->fflags) == rft->fflags)) {
>                         ret = rdtgroup_add_file(kn, rft);
> 
> 
> > 
> >> +			rdtgroup_add_file(rdtgroup_default.kn, rft);
> >> +		}
> >> +	}


-- 
 i.
--8323329-353585656-1681981002=:2051--