From: Reinette Chatre <reinette.chatre@intel.com>
To: Ben Horgan <ben.horgan@arm.com>
Cc: <tony.luck@intel.com>, <x86@kernel.org>, <Dave.Martin@arm.com>,
<james.morse@arm.com>, <babu.moger@amd.com>,
<fenghuay@nvidia.com>, <bp@alien8.de>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] fs/resctrl: Allocate rmid_ptrs[] using kvzalloc_objs()
Date: Thu, 20 Aug 2026 16:25:52 -0700 [thread overview]
Message-ID: <1ac7c71e-1c27-4d71-bea5-0aaebb16bc18@intel.com> (raw)
In-Reply-To: <20260710112322.25516-1-ben.horgan@arm.com>
Hi Ben,
On 7/10/26 4:23 AM, Ben Horgan wrote:
> On an MPAM system the number of entries in rmid_ptrs[] is the number of PARTIDs
> multiplied by the number of PMGs. The maximum possible number of PARTIDs is
> 0x10000 and the maximum number of PMGs is 0x100. On a system pushing the limits
> of the MPAM specification this can be large enough to consistently fail the
> kzalloc_objs() allocation and hence fail to mount the resctrl filesystem.
>
> Switch to allocating rmid_ptrs[] using kvzalloc_objs() so that large allocations
> fall back to vmalloc().
>
> Fixes: 7168ae330e81 ("x86,fs/resctrl: Move the resctrl filesystem code to live in /fs/resctrl")
This is not the patch that added the original allocation but it is the patch
that made it possible for MPAM architecture code to be added. At this point there
is no MPAM support though, could commit 264c285999fc ("arm_mpam: resctrl: Add monitor
initialisation and domain boilerplate") perhaps be more accurate to present when
this change may theoretically be needed?
> Signed-off-by: Ben Horgan <ben.horgan@arm.com>
> ---
Reinette
prev parent reply other threads:[~2026-08-20 23:25 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-10 11:23 [PATCH v1] fs/resctrl: Allocate rmid_ptrs[] using kvzalloc_objs() Ben Horgan
2026-07-10 15:42 ` Luck, Tony
2026-07-13 9:16 ` Ben Horgan
2026-08-20 23:25 ` Reinette Chatre [this message]
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=1ac7c71e-1c27-4d71-bea5-0aaebb16bc18@intel.com \
--to=reinette.chatre@intel.com \
--cc=Dave.Martin@arm.com \
--cc=babu.moger@amd.com \
--cc=ben.horgan@arm.com \
--cc=bp@alien8.de \
--cc=fenghuay@nvidia.com \
--cc=james.morse@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tony.luck@intel.com \
--cc=x86@kernel.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.