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From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Justin Ernst <justin.ernst@hpe.com>,
	russ.anderson@hpe.com, Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Raise maximum number of memory controllers
Date: Tue, 25 Sep 2018 10:50:23 -0700	[thread overview]
Message-ID: <20180925175023.GA16725@agluck-desk> (raw)
In-Reply-To: <20180925152659.GE23986@zn.tnic>

On Tue, Sep 25, 2018 at 05:26:59PM +0200, Borislav Petkov wrote:
> On Tue, Sep 25, 2018 at 09:34:49AM -0500, Justin Ernst wrote:
> > We observe an oops in the skx_edac module during boot.
> > Examining /var/log/messages:
> > [ 3401.985757] EDAC MC0: Giving out device to module skx_edac controller Skylake Socket#0 IMC#0
> > [ 3401.985887] EDAC MC1: Giving out device to module skx_edac controller Skylake Socket#0 IMC#1
> > [ 3401.986014] EDAC MC2: Giving out device to module skx_edac controller Skylake Socket#1 IMC#0
> > ...
> > [ 3401.987318] EDAC MC13: Giving out device to module skx_edac controller Skylake Socket#0 IMC#1
> > [ 3401.987435] EDAC MC14: Giving out device to module skx_edac controller Skylake Socket#1 IMC#0
> > [ 3401.987556] EDAC MC15: Giving out device to module skx_edac controller Skylake Socket#1 IMC#1
> > [ 3401.987579] Too many memory controllers: 16
> > [ 3402.042614] EDAC MC: Removed device 0 for skx_edac Skylake Socket#0 IMC#0
> > 
> > We observe there are two memory controllers per socket, with a limit of 16.
> > Raise the maximum number of memory controllers from 16 to 2 * MAX_NUMNODES (1024).
> 
> Tony,
> 
> can we read that out from the hardware instead of having this silly
> static number?
> 
> Leaving in the rest.

There are way too many places where we use the identifier "bus"
in the edac core and drivers. But I'm not sure that we need a
static array mc_bus[EDAC_MAX_MCS].

Why can't we:


-	mci->bus = &mc_bus[mci->mc_idx];
+	mci->bus = kmalloc(sizeof *(mci->bus), GFP_KERNEL);

and then figure out where to kfree(mci->bus) on driver removal?

Do we every do arithmetic on different mci->bus pointers that
assume they are all part of a single array?

-Tony

WARNING: multiple messages have this Message-ID (diff)
From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Justin Ernst <justin.ernst@hpe.com>,
	russ.anderson@hpe.com, Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Raise maximum number of memory controllers
Date: Tue, 25 Sep 2018 10:50:23 -0700	[thread overview]
Message-ID: <20180925175023.GA16725@agluck-desk> (raw)

On Tue, Sep 25, 2018 at 05:26:59PM +0200, Borislav Petkov wrote:
> On Tue, Sep 25, 2018 at 09:34:49AM -0500, Justin Ernst wrote:
> > We observe an oops in the skx_edac module during boot.
> > Examining /var/log/messages:
> > [ 3401.985757] EDAC MC0: Giving out device to module skx_edac controller Skylake Socket#0 IMC#0
> > [ 3401.985887] EDAC MC1: Giving out device to module skx_edac controller Skylake Socket#0 IMC#1
> > [ 3401.986014] EDAC MC2: Giving out device to module skx_edac controller Skylake Socket#1 IMC#0
> > ...
> > [ 3401.987318] EDAC MC13: Giving out device to module skx_edac controller Skylake Socket#0 IMC#1
> > [ 3401.987435] EDAC MC14: Giving out device to module skx_edac controller Skylake Socket#1 IMC#0
> > [ 3401.987556] EDAC MC15: Giving out device to module skx_edac controller Skylake Socket#1 IMC#1
> > [ 3401.987579] Too many memory controllers: 16
> > [ 3402.042614] EDAC MC: Removed device 0 for skx_edac Skylake Socket#0 IMC#0
> > 
> > We observe there are two memory controllers per socket, with a limit of 16.
> > Raise the maximum number of memory controllers from 16 to 2 * MAX_NUMNODES (1024).
> 
> Tony,
> 
> can we read that out from the hardware instead of having this silly
> static number?
> 
> Leaving in the rest.

There are way too many places where we use the identifier "bus"
in the edac core and drivers. But I'm not sure that we need a
static array mc_bus[EDAC_MAX_MCS].

Why can't we:


-	mci->bus = &mc_bus[mci->mc_idx];
+	mci->bus = kmalloc(sizeof *(mci->bus), GFP_KERNEL);

and then figure out where to kfree(mci->bus) on driver removal?

Do we every do arithmetic on different mci->bus pointers that
assume they are all part of a single array?

-Tony

  reply	other threads:[~2018-09-25 17:50 UTC|newest]

Thread overview: 56+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-25 14:34 [PATCH] Raise maximum number of memory controllers Justin Ernst
2018-09-25 14:34 ` Justin Ernst
2018-09-25 15:26 ` [PATCH] " Borislav Petkov
2018-09-25 15:26   ` Borislav Petkov
2018-09-25 17:50   ` Luck, Tony [this message]
2018-09-25 17:50     ` Luck, Tony
2018-09-25 18:07     ` [PATCH] " Borislav Petkov
2018-09-25 18:07       ` Borislav Petkov
2018-09-26  9:35       ` [PATCH] " Borislav Petkov
2018-09-26  9:35         ` Borislav Petkov
2018-09-26 15:27         ` [PATCH] " Borislav Petkov
2018-09-26 15:27           ` Borislav Petkov
2018-09-26 16:03           ` [PATCH] " Mauro Carvalho Chehab
2018-09-26 16:03             ` Mauro Carvalho Chehab
2018-09-26 16:17             ` [PATCH] " Borislav Petkov
2018-09-26 16:17               ` Borislav Petkov
2018-09-26 17:39               ` [PATCH] " Mauro Carvalho Chehab
2018-09-26 17:39                 ` Mauro Carvalho Chehab
2018-09-26 18:10               ` [PATCH] " Luck, Tony
2018-09-26 18:10                 ` Luck, Tony
2018-09-26 18:23                 ` [PATCH] " Russ Anderson
2018-09-26 18:23                   ` Russ Anderson
2018-09-26 23:02                   ` [PATCH] " Luck, Tony
2018-09-26 23:02                     ` Luck, Tony
2018-09-27  4:52                     ` [PATCH] " Borislav Petkov
2018-09-27  4:52                       ` Borislav Petkov
2018-09-27 21:44                       ` [PATCH] " Luck, Tony
2018-09-27 21:44                         ` Luck, Tony
2018-09-27 22:03                         ` [PATCH] " Borislav Petkov
2018-09-27 22:03                           ` Borislav Petkov
2018-09-28  1:10                           ` [PATCH] " Mauro Carvalho Chehab
2018-09-28  1:10                             ` Mauro Carvalho Chehab
2018-10-01 12:47                             ` [PATCH] " Borislav Petkov
2018-10-01 12:47                               ` Borislav Petkov
2018-10-01 22:43                               ` [PATCH] EDAC: Don't add devices under /sys/bus/edac Luck, Tony
2018-10-01 22:43                                 ` Luck, Tony
2018-10-02  1:22                                 ` [PATCH] " Mauro Carvalho Chehab
2018-10-02  1:22                                   ` Mauro Carvalho Chehab
2018-10-02 15:51                                   ` [PATCH] " Ernst, Justin
2018-10-02 15:51                                     ` Justin Ernst
2018-10-02 16:26                                     ` [PATCH] " Borislav Petkov
2018-10-02 16:26                                       ` Borislav Petkov
2018-11-06 14:45                                       ` [PATCH] " Borislav Petkov
2018-11-06 14:45                                         ` Borislav Petkov
2018-11-13 19:09                                         ` [PATCH] " Ernst, Justin
2018-11-13 19:09                                           ` Justin Ernst
2018-11-13 19:15                                           ` [PATCH] " Borislav Petkov
2018-11-13 19:15                                             ` Borislav Petkov
2018-09-26  7:55 ` [PATCH] Raise maximum number of memory controllers Zhuo, Qiuxu
2018-09-26  7:55   ` Qiuxu Zhuo
2018-09-26 13:53   ` [PATCH] " Russ Anderson
2018-09-26 13:53     ` Russ Anderson
2018-09-26 16:13 ` [PATCH] " Aristeu Rozanski
2018-09-26 16:13   ` Aristeu Rozanski
2018-09-27  5:56 ` [PATCH] " Borislav Petkov
2018-09-27  5:56   ` Borislav Petkov

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