From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Shiju Jose <shiju.jose@huawei.com>,
"linux-cxl@vger.kernel.org" <linux-cxl@vger.kernel.org>,
"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
"dave@stgolabs.net" <dave@stgolabs.net>,
"dave.jiang@intel.com" <dave.jiang@intel.com>,
"alison.schofield@intel.com" <alison.schofield@intel.com>,
"vishal.l.verma@intel.com" <vishal.l.verma@intel.com>,
"ira.weiny@intel.com" <ira.weiny@intel.com>,
"linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"david@redhat.com" <david@redhat.com>,
"Vilas.Sridharan@amd.com" <Vilas.Sridharan@amd.com>,
"leo.duran@amd.com" <leo.duran@amd.com>,
"Yazen.Ghannam@amd.com" <Yazen.Ghannam@amd.com>,
"rientjes@google.com" <rientjes@google.com>,
"jiaqiyan@google.com" <jiaqiyan@google.com>,
"tony.luck@intel.com" <tony.luck@intel.com>,
"Jon.Grimm@amd.com" <Jon.Grimm@amd.com>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"rafael@kernel.org" <rafael@kernel.org>,
"lenb@kernel.org" <lenb@kernel.org>,
"naoya.horiguchi@nec.com" <naoya.horiguchi@nec.com>,
"james.morse@arm.com" <james.morse@arm.com>,
"jthoughton@google.com" <jthoughton@google.com>,
"somasundaram.a@hpe.com" <somasundaram.a@hpe.com>,
"erdemaktas@google.com" <erdemaktas@google.com>,
"pgonda@google.com" <pgonda@google.com>,
"duenwen@google.com" <duenwen@google.com>,
"mike.malvestuto@intel.com" <mike.malvestuto@intel.com>,
"gthelen@google.com" <gthelen@google.com>,
"wschwartz@amperecomputing.com" <wschwartz@amperecomputing.com>,
"dferguson@amperecomputing.com" <dferguson@amperecomputing.com>,
"wbs@os.amperecomputing.com" <wbs@os.amperecomputing.com>,
"nifan.cxl@gmail.com" <nifan.cxl@gmail.com>,
tanxiaofei <tanxiaofei@huawei.com>,
"Zengtao (B)" <prime.zeng@hisilicon.com>,
"kangkang.shen@futurewei.com" <kangkang.shen@futurewei.com>,
wanghuiqiang <wanghuiqiang@huawei.com>,
Linuxarm <linuxarm@huawei.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
Jean Delvare <jdelvare@suse.com>,
Guenter Roeck <linux@roeck-us.net>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>
Subject: Re: [RFC PATCH v8 01/10] ras: scrub: Add scrub subsystem
Date: Fri, 10 May 2024 14:31:41 +0100 [thread overview]
Message-ID: <20240510143141.000042da@Huawei.com> (raw)
In-Reply-To: <D9511DC1-1566-473A-A426-111BB1F7F9F0@alien8.de>
> How hard is that "jump through hoops" thing anyway?
I'd conservatively estimate 500 lines of duplicated code from the CXL
subsystem just to handle the setup and discovery of the mailbox, plus
all the checks needed to establish the device is in a state to reply.
Also locking or module load ordering constraints because we need
to ensure mutual exclusion on that mailbox between this module and the CXL
core. So it would approximately triple the size of this driver to
check for CXL scrub support. Not to mention hotplug - which could
possibly be solved with appropriate udev rules to try loading this again
whenever a CXL memory device gets plugged in.
Alternative would be to make this ras class driver dependent on the CXL
driver stack running first. Thus if you wanted RAS2 ACPI table support, you'd
need to load a whole bunch of CXL stuff.
Add another similar driver in future and we get another few 100 lines of code
or another dependency. To me those numbers make it unsustainable.
>
> You mean it should load so that when booting an allmodconfig kernel there are not enough modules which are loading so lemme load one more. And then I need to go and rmmod them all before I need to do localmodconfig and build a tailored kernel for the machine.
>
> Or is there some other reason to load silly modules, use up resources for no good reason whatsoever and bloat the machine?
As Dan, Shiju and I observed (and Shiju tested to be sure we weren't
getting it wrong), normal setups including your allmodconfig
build would not even load the driver. What are we missing?
Jonathan
next prev parent reply other threads:[~2024-05-10 13:31 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 16:47 [RFC PATCH v8 00/10] ras: scrub: introduce subsystem + CXL/ACPI-RAS2 drivers shiju.jose
2024-04-19 16:47 ` [RFC PATCH v8 01/10] ras: scrub: Add scrub subsystem shiju.jose
2024-04-24 20:25 ` fan
2024-04-25 10:38 ` Shiju Jose
2024-04-25 10:15 ` Borislav Petkov
2024-04-25 18:11 ` Shiju Jose
2024-05-06 10:30 ` Borislav Petkov
2024-05-08 16:59 ` Shiju Jose
2024-05-08 17:20 ` Borislav Petkov
2024-05-08 17:44 ` Shiju Jose
2024-05-08 19:25 ` Borislav Petkov
2024-05-09 9:19 ` Jonathan Cameron
2024-05-09 15:52 ` Borislav Petkov
2024-05-09 20:03 ` Borislav Petkov
2024-05-09 21:21 ` Dan Williams
2024-05-09 21:51 ` Borislav Petkov
2024-05-09 22:59 ` Dan Williams
2024-05-10 9:25 ` Borislav Petkov
2024-05-10 17:13 ` Dan Williams
2024-05-11 10:17 ` Borislav Petkov
2024-05-17 11:15 ` Jonathan Cameron
2024-05-17 11:44 ` Jonathan Cameron
2024-05-21 8:06 ` Borislav Petkov
2024-05-22 9:40 ` Jonathan Cameron
2024-05-27 9:09 ` Borislav Petkov
2024-05-20 10:54 ` Shiju Jose
2024-05-20 11:58 ` Jonathan Cameron
2024-05-27 9:21 ` Borislav Petkov
2024-05-28 9:06 ` Jonathan Cameron
2024-05-10 13:31 ` Jonathan Cameron [this message]
2024-05-09 21:47 ` Dan Williams
2024-05-10 9:03 ` Jonathan Cameron
2024-04-19 16:47 ` [RFC PATCH v8 02/10] cxl/mbox: Add GET_SUPPORTED_FEATURES mailbox command shiju.jose
2024-04-19 16:47 ` [RFC PATCH v8 03/10] cxl/mbox: Add GET_FEATURE " shiju.jose
2024-04-24 23:19 ` fan
2024-04-25 10:38 ` Shiju Jose
2024-04-19 16:47 ` [RFC PATCH v8 04/10] cxl/mbox: Add SET_FEATURE " shiju.jose
2024-04-25 17:26 ` fan
2024-04-19 16:47 ` [RFC PATCH v8 05/10] cxl/memscrub: Add CXL device patrol scrub control feature shiju.jose
2024-04-26 23:56 ` fan
2024-04-29 11:20 ` Shiju Jose
2024-04-29 12:21 ` Jonathan Cameron
2024-05-10 0:26 ` Dan Williams
2024-05-10 11:23 ` Jonathan Cameron
2024-04-19 16:47 ` [RFC PATCH v8 06/10] ACPICA: Add __free() based cleanup function for acpi_put_table shiju.jose
2024-04-19 18:06 ` Jonathan Cameron
2024-04-19 16:47 ` [RFC PATCH v8 07/10] platform: Add __free() based cleanup function for platform_device_put shiju.jose
2024-04-19 16:47 ` [RFC PATCH v8 08/10] ACPI:RAS2: Add ACPI RAS2 driver shiju.jose
2024-04-19 16:47 ` [RFC PATCH v8 09/10] ras: scrub: Add scrub control attributes for ACPI RAS2 shiju.jose
2024-04-19 16:47 ` [RFC PATCH v8 10/10] ras: scrub: ACPI RAS2: Add memory ACPI RAS2 driver shiju.jose
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240510143141.000042da@Huawei.com \
--to=jonathan.cameron@huawei.com \
--cc=Jon.Grimm@amd.com \
--cc=Vilas.Sridharan@amd.com \
--cc=Yazen.Ghannam@amd.com \
--cc=alison.schofield@intel.com \
--cc=bp@alien8.de \
--cc=dan.j.williams@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=dave.jiang@intel.com \
--cc=dave@stgolabs.net \
--cc=david@redhat.com \
--cc=dferguson@amperecomputing.com \
--cc=dmitry.torokhov@gmail.com \
--cc=duenwen@google.com \
--cc=erdemaktas@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=gthelen@google.com \
--cc=ira.weiny@intel.com \
--cc=james.morse@arm.com \
--cc=jdelvare@suse.com \
--cc=jiaqiyan@google.com \
--cc=jthoughton@google.com \
--cc=kangkang.shen@futurewei.com \
--cc=lenb@kernel.org \
--cc=leo.duran@amd.com \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-cxl@vger.kernel.org \
--cc=linux-edac@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux@roeck-us.net \
--cc=linuxarm@huawei.com \
--cc=mike.malvestuto@intel.com \
--cc=naoya.horiguchi@nec.com \
--cc=nifan.cxl@gmail.com \
--cc=pgonda@google.com \
--cc=prime.zeng@hisilicon.com \
--cc=rafael@kernel.org \
--cc=rientjes@google.com \
--cc=shiju.jose@huawei.com \
--cc=somasundaram.a@hpe.com \
--cc=tanxiaofei@huawei.com \
--cc=tony.luck@intel.com \
--cc=vishal.l.verma@intel.com \
--cc=wanghuiqiang@huawei.com \
--cc=wbs@os.amperecomputing.com \
--cc=wschwartz@amperecomputing.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).