public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Balbir Singh <sblbir@amazon.com>
To: <tglx@linutronix.de>, <mingo@redhat.com>
Cc: <peterz@infradead.org>, <linux-kernel@vger.kernel.org>,
	<keescook@chromium.org>, Balbir Singh <sblbir@amazon.com>
Subject: [PATCH v1 2/3] Documentation: Update the new SIGBUS behaviour for tasks
Date: Wed, 18 Nov 2020 10:49:33 +1100	[thread overview]
Message-ID: <20201117234934.25985-3-sblbir@amazon.com> (raw)
In-Reply-To: <20201117234934.25985-1-sblbir@amazon.com>

Update the documentation to mention that a SIGBUS will be sent
to tasks that opt-into L1D flushing and execute on non-SMT cores.

Signed-off-by: Balbir Singh <sblbir@amazon.com>
---
To be applied on top of tip commit id
767d46ab566dd489733666efe48732d523c8c332

 Documentation/admin-guide/hw-vuln/l1d_flush.rst | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/hw-vuln/l1d_flush.rst b/Documentation/admin-guide/hw-vuln/l1d_flush.rst
index adc4ecc72361..c6a0713c8271 100644
--- a/Documentation/admin-guide/hw-vuln/l1d_flush.rst
+++ b/Documentation/admin-guide/hw-vuln/l1d_flush.rst
@@ -63,8 +63,8 @@ This can be addressed by controlled placement of processes on physical CPU
 cores or by disabling SMT. See the relevant chapter in the L1TF mitigation
 document: :ref:`Documentation/admin-guide/hw-vuln/l1tf.rst <smt_control>`.
 
-**NOTE** : Checks have been added to ensure that the prctl API associated
+**NOTE** : Checks have been added to ensure that the L1D flush associated
 with the opt-in will work only when the task affinity of the task opting
-in, is limited to cores running in non-SMT mode. The same checks are made
-when L1D is flushed.  Changing the affinity after opting in, would result
-in flushes not working on cores that are in non-SMT mode.
+in, is limited to cores running in non-SMT mode. Changing the affinity after
+opting in, would result in the task getting a SIGBUS when it executes on
+the flush is needed and the task is executing on the non-SMT core.
-- 
2.17.1


  parent reply	other threads:[~2020-11-17 23:50 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17 23:49 [PATCH v1 0/3] Fixes to L1D flushing (on top of linux-next and Balbir Singh
2020-11-17 23:49 ` [PATCH v1 1/3] x86/mm: change l1d flush runtime prctl behaviour Balbir Singh
2020-11-17 23:49 ` Balbir Singh [this message]
2020-11-17 23:49 ` [PATCH v1 3/3] Documentation/l1d_flush: Fix up warning with labels Balbir Singh

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=20201117234934.25985-3-sblbir@amazon.com \
    --to=sblbir@amazon.com \
    --cc=keescook@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=peterz@infradead.org \
    --cc=tglx@linutronix.de \
    /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