From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
linux-sgx@vger.kernel.org, kai.svahn@intel.com,
bruce.schlobohm@intel.com
Subject: Re: [PATCH RFC] x86/sgx: Allocate form local NUMA node first
Date: Wed, 24 Jun 2020 17:57:52 -0700 [thread overview]
Message-ID: <20200625005752.GI25092@linux.intel.com> (raw)
In-Reply-To: <59f91e2e-56c2-0395-0ed4-df76a9d7d252@intel.com>
On Wed, Jun 24, 2020 at 05:25:59PM -0700, Dave Hansen wrote:
> On 6/24/20 4:54 PM, Sean Christopherson wrote:
> >> Does this actually work?
> >>
> >> The node span (->node_start_pfn through start+->node_spanned_pages) only
> >> contains pages which the OS is actively managing, usually RAM but
> >> sometimes also persistent memory. This has some assumption that the SGX
> >> PFNs are within the node's span. I would only _expect_ that to happen
> >> if the node was built like this:
> >>
> >> | Node-X RAM | EPC | Node-X RAM |
> >>
> >> If the EPC was on either end:
> >>
> >> | Node-X RAM | EPC |
> >> or
> >> | EPC | Node-X RAM |
> >>
> >> I suspect that the pgdat span wouldn't include EPC. EPC is, if I
> >> remember correctly, a E820_RESERVED region.
> > It is indeed E820_RESERVED, but the BIOS WG for ICX states that EPC regions
> > should be enumerated in ACPI SRAT along with regular memory.
> >
> > But, I haven't actually verified that info makes its way into the kernel's
> > pgdata stuff.
>
> Considering this, are we all agreed that this patch is in no condition
> to be submitted upstream?
Yes, it needs to be tested first.
I like the resulting code more than what we have now, but I see no reason to
change it at this stage unless one of the maintainers actually complains.
next prev parent reply other threads:[~2020-06-25 0:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 4:39 [PATCH RFC] x86/sgx: Allocate form local NUMA node first Jarkko Sakkinen
2020-06-24 23:12 ` Jarkko Sakkinen
2020-06-24 23:24 ` Dave Hansen
2020-06-24 23:54 ` Sean Christopherson
2020-06-25 0:25 ` Dave Hansen
2020-06-25 0:57 ` Sean Christopherson [this message]
2020-06-25 2:57 ` Jarkko Sakkinen
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=20200625005752.GI25092@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=bruce.schlobohm@intel.com \
--cc=dave.hansen@intel.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=kai.svahn@intel.com \
--cc=linux-sgx@vger.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.