From: Dave Chinner <david@fromorbit.com>
To: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>, Matthew Wilcox <mawilcox@microsoft.com>,
linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org,
Steven Rostedt <rostedt@goodmis.org>,
linux-mm@kvack.org, Ingo Molnar <mingo@redhat.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
linux-ext4@vger.kernel.org, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH 3/6] dax: add tracepoint infrastructure, PMD tracing
Date: Fri, 25 Nov 2016 14:00:59 +1100 [thread overview]
Message-ID: <20161125030059.GY31101@dastard> (raw)
In-Reply-To: <1479926662-21718-4-git-send-email-ross.zwisler@linux.intel.com>
On Wed, Nov 23, 2016 at 11:44:19AM -0700, Ross Zwisler wrote:
> Tracepoints are the standard way to capture debugging and tracing
> information in many parts of the kernel, including the XFS and ext4
> filesystems. Create a tracepoint header for FS DAX and add the first DAX
> tracepoints to the PMD fault handler. This allows the tracing for DAX to
> be done in the same way as the filesystem tracing so that developers can
> look at them together and get a coherent idea of what the system is doing.
>
> I added both an entry and exit tracepoint because future patches will add
> tracepoints to child functions of dax_iomap_pmd_fault() like
> dax_pmd_load_hole() and dax_pmd_insert_mapping(). We want those messages to
> be wrapped by the parent function tracepoints so the code flow is more
> easily understood. Having entry and exit tracepoints for faults also
> allows us to easily see what filesystems functions were called during the
> fault. These filesystem functions get executed via iomap_begin() and
> iomap_end() calls, for example, and will have their own tracepoints.
>
> For PMD faults we primarily want to understand the faulting address and
> whether it fell back to 4k faults. If it fell back to 4k faults the
> tracepoints should let us understand why.
>
> I named the new tracepoint header file "fs_dax.h" to allow for device DAX
> to have its own separate tracing header in the same directory at some
> point.
>
> Here is an example output for these events from a successful PMD fault:
>
> big-2057 [000] .... 136.396855: dax_pmd_fault: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400
>
> big-2057 [000] .... 136.397943: dax_pmd_fault_done: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400 NOPAGE
Can we make the output use the same format as most of the filesystem
code? i.e. the output starts with backing device + inode number like
so:
xfs_ilock: dev 8:96 ino 0x493 flags ILOCK_EXCL....
This way we can filter the output easily across both dax and
filesystem tracepoints with 'grep "ino 0x493"'...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
Dan Williams <dan.j.williams@intel.com>,
Ingo Molnar <mingo@redhat.com>, Jan Kara <jack@suse.cz>,
Matthew Wilcox <mawilcox@microsoft.com>,
Steven Rostedt <rostedt@goodmis.org>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-nvdimm@ml01.01.org
Subject: Re: [PATCH 3/6] dax: add tracepoint infrastructure, PMD tracing
Date: Fri, 25 Nov 2016 14:00:59 +1100 [thread overview]
Message-ID: <20161125030059.GY31101@dastard> (raw)
In-Reply-To: <1479926662-21718-4-git-send-email-ross.zwisler@linux.intel.com>
On Wed, Nov 23, 2016 at 11:44:19AM -0700, Ross Zwisler wrote:
> Tracepoints are the standard way to capture debugging and tracing
> information in many parts of the kernel, including the XFS and ext4
> filesystems. Create a tracepoint header for FS DAX and add the first DAX
> tracepoints to the PMD fault handler. This allows the tracing for DAX to
> be done in the same way as the filesystem tracing so that developers can
> look at them together and get a coherent idea of what the system is doing.
>
> I added both an entry and exit tracepoint because future patches will add
> tracepoints to child functions of dax_iomap_pmd_fault() like
> dax_pmd_load_hole() and dax_pmd_insert_mapping(). We want those messages to
> be wrapped by the parent function tracepoints so the code flow is more
> easily understood. Having entry and exit tracepoints for faults also
> allows us to easily see what filesystems functions were called during the
> fault. These filesystem functions get executed via iomap_begin() and
> iomap_end() calls, for example, and will have their own tracepoints.
>
> For PMD faults we primarily want to understand the faulting address and
> whether it fell back to 4k faults. If it fell back to 4k faults the
> tracepoints should let us understand why.
>
> I named the new tracepoint header file "fs_dax.h" to allow for device DAX
> to have its own separate tracing header in the same directory at some
> point.
>
> Here is an example output for these events from a successful PMD fault:
>
> big-2057 [000] .... 136.396855: dax_pmd_fault: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400
>
> big-2057 [000] .... 136.397943: dax_pmd_fault_done: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400 NOPAGE
Can we make the output use the same format as most of the filesystem
code? i.e. the output starts with backing device + inode number like
so:
xfs_ilock: dev 8:96 ino 0x493 flags ILOCK_EXCL....
This way we can filter the output easily across both dax and
filesystem tracepoints with 'grep "ino 0x493"'...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
WARNING: multiple messages have this Message-ID (diff)
From: Dave Chinner <david@fromorbit.com>
To: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: linux-kernel@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Hellwig <hch@lst.de>,
Dan Williams <dan.j.williams@intel.com>,
Ingo Molnar <mingo@redhat.com>, Jan Kara <jack@suse.cz>,
Matthew Wilcox <mawilcox@microsoft.com>,
Steven Rostedt <rostedt@goodmis.org>,
linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-nvdimm@lists.01.org
Subject: Re: [PATCH 3/6] dax: add tracepoint infrastructure, PMD tracing
Date: Fri, 25 Nov 2016 14:00:59 +1100 [thread overview]
Message-ID: <20161125030059.GY31101@dastard> (raw)
In-Reply-To: <1479926662-21718-4-git-send-email-ross.zwisler@linux.intel.com>
On Wed, Nov 23, 2016 at 11:44:19AM -0700, Ross Zwisler wrote:
> Tracepoints are the standard way to capture debugging and tracing
> information in many parts of the kernel, including the XFS and ext4
> filesystems. Create a tracepoint header for FS DAX and add the first DAX
> tracepoints to the PMD fault handler. This allows the tracing for DAX to
> be done in the same way as the filesystem tracing so that developers can
> look at them together and get a coherent idea of what the system is doing.
>
> I added both an entry and exit tracepoint because future patches will add
> tracepoints to child functions of dax_iomap_pmd_fault() like
> dax_pmd_load_hole() and dax_pmd_insert_mapping(). We want those messages to
> be wrapped by the parent function tracepoints so the code flow is more
> easily understood. Having entry and exit tracepoints for faults also
> allows us to easily see what filesystems functions were called during the
> fault. These filesystem functions get executed via iomap_begin() and
> iomap_end() calls, for example, and will have their own tracepoints.
>
> For PMD faults we primarily want to understand the faulting address and
> whether it fell back to 4k faults. If it fell back to 4k faults the
> tracepoints should let us understand why.
>
> I named the new tracepoint header file "fs_dax.h" to allow for device DAX
> to have its own separate tracing header in the same directory at some
> point.
>
> Here is an example output for these events from a successful PMD fault:
>
> big-2057 [000] .... 136.396855: dax_pmd_fault: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400
>
> big-2057 [000] .... 136.397943: dax_pmd_fault_done: shared mapping write
> address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200
> max_pgoff 0x1400 NOPAGE
Can we make the output use the same format as most of the filesystem
code? i.e. the output starts with backing device + inode number like
so:
xfs_ilock: dev 8:96 ino 0x493 flags ILOCK_EXCL....
This way we can filter the output easily across both dax and
filesystem tracepoints with 'grep "ino 0x493"'...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-11-25 3:01 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-23 18:44 [PATCH 0/6] introduce DAX tracepoint support Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` [PATCH 1/6] dax: fix build breakage with ext4, dax and !iomap Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-24 9:02 ` Jan Kara
2016-11-24 9:02 ` Jan Kara
2016-11-24 9:02 ` Jan Kara
2016-11-24 9:02 ` Jan Kara
2016-11-28 19:15 ` Ross Zwisler
2016-11-28 19:15 ` Ross Zwisler
2016-11-28 19:15 ` Ross Zwisler
2016-11-29 8:53 ` Jan Kara
2016-11-29 8:53 ` Jan Kara
2016-11-29 8:53 ` Jan Kara
2016-11-29 8:53 ` Jan Kara
2016-11-30 19:04 ` Ross Zwisler
2016-11-30 19:04 ` Ross Zwisler
2016-11-30 19:04 ` Ross Zwisler
2016-11-30 19:04 ` Ross Zwisler
2016-12-01 7:53 ` Jan Kara
2016-12-01 7:53 ` Jan Kara
2016-12-01 7:53 ` Jan Kara
2016-12-01 7:53 ` Jan Kara
2016-11-23 18:44 ` [PATCH 2/6] dax: remove leading space from labels Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-24 9:11 ` Jan Kara
2016-11-24 9:11 ` Jan Kara
2016-11-24 9:11 ` Jan Kara
2016-11-24 19:42 ` Dan Williams
2016-11-24 19:42 ` Dan Williams
2016-11-24 19:42 ` Dan Williams
2016-11-28 19:20 ` Ross Zwisler
2016-11-28 19:20 ` Ross Zwisler
2016-11-28 19:20 ` Ross Zwisler
2016-11-23 18:44 ` [PATCH 3/6] dax: add tracepoint infrastructure, PMD tracing Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-24 9:16 ` Jan Kara
2016-11-24 9:16 ` Jan Kara
2016-11-24 9:16 ` Jan Kara
2016-11-24 9:16 ` Jan Kara
2016-11-24 17:32 ` Al Viro
2016-11-24 17:32 ` Al Viro
2016-11-24 17:32 ` Al Viro
2016-11-24 17:32 ` Al Viro
2016-11-25 2:49 ` Dave Chinner
2016-11-25 2:49 ` Dave Chinner
2016-11-25 2:49 ` Dave Chinner
2016-11-25 2:49 ` Dave Chinner
2016-11-25 4:14 ` Al Viro
2016-11-25 4:14 ` Al Viro
2016-11-25 4:14 ` Al Viro
2016-11-25 4:14 ` Al Viro
2016-11-25 7:06 ` Dave Chinner
2016-11-25 7:06 ` Dave Chinner
2016-11-25 7:06 ` Dave Chinner
2016-11-25 7:06 ` Dave Chinner
2016-11-25 7:37 ` Al Viro
2016-11-25 7:37 ` Al Viro
2016-11-25 7:37 ` Al Viro
2016-11-25 7:37 ` Al Viro
2016-11-25 19:51 ` Linus Torvalds
2016-11-25 19:51 ` Linus Torvalds
2016-11-25 19:51 ` Linus Torvalds
2016-11-25 20:36 ` Mike Marshall
2016-11-25 20:36 ` Mike Marshall
2016-11-25 20:36 ` Mike Marshall
2016-11-25 21:48 ` Theodore Ts'o
2016-11-25 21:48 ` Theodore Ts'o
2016-11-25 21:48 ` Theodore Ts'o
2016-11-25 23:38 ` Linus Torvalds
2016-11-25 23:38 ` Linus Torvalds
2016-11-25 23:38 ` Linus Torvalds
2016-11-28 8:33 ` Jan Kara
2016-11-28 8:33 ` Jan Kara
2016-11-28 8:33 ` Jan Kara
2016-11-27 22:42 ` Dave Chinner
2016-11-27 22:42 ` Dave Chinner
2016-11-27 22:42 ` Dave Chinner
2016-11-28 0:58 ` Linus Torvalds
2016-11-28 0:58 ` Linus Torvalds
2016-11-28 0:58 ` Linus Torvalds
2016-11-28 1:45 ` Al Viro
2016-11-28 1:45 ` Al Viro
2016-11-28 9:09 ` Dave Chinner
2016-11-28 9:09 ` Dave Chinner
2016-11-28 9:09 ` Dave Chinner
2016-11-25 3:00 ` Dave Chinner [this message]
2016-11-25 3:00 ` Dave Chinner
2016-11-25 3:00 ` Dave Chinner
2016-11-28 22:46 ` Ross Zwisler
2016-11-28 22:46 ` Ross Zwisler
2016-11-28 22:46 ` Ross Zwisler
2016-11-28 22:46 ` Ross Zwisler
2016-11-29 2:02 ` Dave Chinner
2016-11-29 2:02 ` Dave Chinner
2016-11-29 2:02 ` Dave Chinner
2017-03-08 22:05 ` Mike Marshall
2017-03-08 22:05 ` Mike Marshall
2017-03-08 22:05 ` Mike Marshall
2017-03-08 22:05 ` Mike Marshall
2016-11-23 18:44 ` [PATCH 4/6] dax: update MAINTAINERS entries for FS DAX Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` [PATCH 5/6] dax: add tracepoints to dax_pmd_load_hole() Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-24 9:20 ` Jan Kara
2016-11-24 9:20 ` Jan Kara
2016-11-24 9:20 ` Jan Kara
2016-11-23 18:44 ` [PATCH 6/6] dax: add tracepoints to dax_pmd_insert_mapping() Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-23 18:44 ` Ross Zwisler
2016-11-24 9:22 ` Jan Kara
2016-11-24 9:22 ` Jan Kara
2016-11-24 9:22 ` Jan Kara
2016-11-24 9:22 ` Jan Kara
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=20161125030059.GY31101@dastard \
--to=david@fromorbit.com \
--cc=akpm@linux-foundation.org \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-nvdimm@lists.01.org \
--cc=mawilcox@microsoft.com \
--cc=mingo@redhat.com \
--cc=ross.zwisler@linux.intel.com \
--cc=rostedt@goodmis.org \
--cc=viro@zeniv.linux.org.uk \
/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.