From: Steven Rostedt <rostedt@goodmis.org>
To: Alexander Graf <graf@amazon.com>
Cc: <linux-kernel@vger.kernel.org>,
<linux-trace-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
<devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<kexec@lists.infradead.org>, <linux-doc@vger.kernel.org>,
<x86@kernel.org>, Eric Biederman <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
Mark Rutland <mark.rutland@arm.com>,
"Tom Lendacky" <thomas.lendacky@amd.com>,
Ashish Kalra <ashish.kalra@amd.com>,
James Gowans <jgowans@amazon.com>,
Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>,
<arnd@arndb.de>, <pbonzini@redhat.com>,
<madvenka@linux.microsoft.com>,
Anthony Yznaga <anthony.yznaga@oracle.com>,
Usama Arif <usama.arif@bytedance.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [PATCH 08/15] tracing: Introduce names for ring buffers
Date: Tue, 12 Dec 2023 19:15:46 -0500 [thread overview]
Message-ID: <20231212191546.603c0703@gandalf.local.home> (raw)
In-Reply-To: <20231213000452.88295-9-graf@amazon.com>
On Wed, 13 Dec 2023 00:04:45 +0000
Alexander Graf <graf@amazon.com> wrote:
> With KHO (Kexec HandOver), we want to preserve trace buffers across
> kexec. To carry over their state between kernels, the kernel needs a
> common handle for them that exists on both sides. As handle we introduce
> names for ring buffers. In a follow-up patch, the kernel can then use
> these names to recover buffer contents for specific ring buffers.
>
Is there a way to use the trace_array name instead?
The trace_array is the structure that represents each tracing instance. And
it already has a name field. And if you can get the associated ring buffer
from that too.
struct trace_array *tr;
tr->array_buffer.buffer
tr->name
When you do: mkdir /sys/kernel/tracing/instance/foo
You create a new trace_array instance where tr->name = "foo" and allocates
the buffer for it as well.
-- Steve
next prev parent reply other threads:[~2023-12-13 0:15 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-13 0:04 [PATCH 00/15] kexec: Allow preservation of ftrace buffers Alexander Graf
2023-12-13 0:04 ` [PATCH 01/15] mm,memblock: Add support for scratch memory Alexander Graf
2023-12-13 0:04 ` [PATCH 02/15] memblock: Declare scratch memory as CMA Alexander Graf
2023-12-13 11:32 ` kernel test robot
2023-12-13 0:04 ` [PATCH 03/15] kexec: Add Kexec HandOver (KHO) generation helpers Alexander Graf
2023-12-13 18:36 ` Stanislav Kinsburskii
2023-12-13 23:36 ` Alexander Graf
2023-12-13 0:04 ` [PATCH 04/15] kexec: Add KHO parsing support Alexander Graf
2023-12-13 18:56 ` Stanislav Kinsburskii
2023-12-13 0:04 ` [PATCH 05/15] kexec: Add KHO support to kexec file loads Alexander Graf
2023-12-13 0:04 ` [PATCH 06/15] arm64: Add KHO support Alexander Graf
2023-12-13 11:22 ` kernel test robot
2023-12-13 13:41 ` kernel test robot
2023-12-14 22:36 ` Rob Herring
2023-12-18 23:01 ` Alexander Graf
2023-12-13 0:04 ` [PATCH 07/15] x86: " Alexander Graf
2023-12-13 0:04 ` [PATCH 08/15] tracing: Introduce names for ring buffers Alexander Graf
2023-12-13 0:15 ` Steven Rostedt [this message]
2023-12-13 0:35 ` Alexander Graf
2023-12-13 0:44 ` Steven Rostedt
2023-12-13 11:22 ` kernel test robot
2023-12-13 0:04 ` [PATCH 09/15] tracing: Introduce names for events Alexander Graf
2023-12-13 0:49 ` Steven Rostedt
2023-12-13 0:04 ` [PATCH 10/15] tracing: Introduce kho serialization Alexander Graf
2023-12-13 0:04 ` [PATCH 11/15] tracing: Add kho serialization of trace buffers Alexander Graf
2023-12-13 0:04 ` [PATCH 12/15] tracing: Recover trace buffers from kexec handover Alexander Graf
2023-12-13 0:04 ` [PATCH 13/15] tracing: Add kho serialization of trace events Alexander Graf
2023-12-13 0:04 ` [PATCH 14/15] tracing: Recover trace events from kexec handover Alexander Graf
2023-12-13 0:04 ` [PATCH 15/15] tracing: Add config option for " Alexander Graf
2023-12-14 14:58 ` [PATCH 00/15] kexec: Allow preservation of ftrace buffers Eric W. Biederman
2023-12-14 16:02 ` Alexander Graf
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=20231212191546.603c0703@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=anthony.yznaga@oracle.com \
--cc=arnd@arndb.de \
--cc=ashish.kalra@amd.com \
--cc=benh@kernel.crashing.org \
--cc=devicetree@vger.kernel.org \
--cc=dwmw@amazon.co.uk \
--cc=ebiederm@xmission.com \
--cc=graf@amazon.com \
--cc=hpa@zytor.com \
--cc=jgowans@amazon.com \
--cc=kexec@lists.infradead.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=madvenka@linux.microsoft.com \
--cc=mark.rutland@arm.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=robh+dt@kernel.org \
--cc=skinsburskii@linux.microsoft.com \
--cc=thomas.lendacky@amd.com \
--cc=usama.arif@bytedance.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox