Boot Time - Revision history

Joe: /* Articles and Presentations */

2013-03-11T10:38:34Z

‎Articles and Presentations

Wmat: Added the ELC2013 Contest section

2013-02-13T17:59:05Z

Added the ELC2013 Contest section

Joe: /* Articles and Presentations */

2013-02-11T18:56:32Z

‎Articles and Presentations

Joe: /* Articles and Presentations */

2013-02-11T18:55:56Z

‎Articles and Presentations

Jserv: update Checkpointing presentation

2012-11-23T09:45:28Z

update Checkpointing presentation

Jserv: Add "Implement Checkpointing for Android" presentation

2012-06-27T05:32:25Z

Add "Implement Checkpointing for Android" presentation

Jserv: Add materials from Texas Instruments Embedded Processors Wiki

2012-03-04T22:24:38Z

Add materials from Texas Instruments Embedded Processors Wiki

Jserv: Add 0xlab's boot time optimization presentation

2012-01-04T06:12:45Z

Add 0xlab's boot time optimization presentation

Trevj: /* Boot time check list */ typo:uncomressed -> uncompressed, blockquote for Sascha Hauer quote

2011-11-03T19:39:26Z

‎Boot time check list: typo:uncomressed -> uncompressed, blockquote for Sascha Hauer quote

Cschalle: Add extra category

2011-10-28T06:34:29Z

Add extra category

@@ Line 115: / Line 115: @@
 == Articles and Presentations ==
-* "Boot Time Optimizations" - ([http://www.elinux.org/images/d/d1/Alexandre_Belloni_boottime_optimizations.pdf Slides] | [http://free-electrons.com/pub/video/2012/elce/elce-2012-belloni-boot-time-optimizations.webm Video])
+* "Boot Time Optimizations" - ([http://elinux.org/images/d/d1/Alexandre_Belloni_boottime_optimizations.pdf Slides] | [http://free-electrons.com/pub/video/2012/elce/elce-2012-belloni-boot-time-optimizations.webm Video])
 ** Alexandre Belloni has presented at ELC Europe on February 20-22, 2012
 ** [http://free-electrons.com/blog/elce-2012-videos/ Main link at Free-Electrons]

← Older revision		Revision as of 17:59, 13 February 2013
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		+	==[[File:Robot64x64.png]] ELC2013 Tech Zone Contest==
		+	<div style="margin:0; margin-top:10px; margin-right:10px; border:1px solid #dfdfdf; padding:0 1em 1em 1em; background-color:#ffffcc; align:right; ">
		+	To add a link to your new page use the following wiki link format:
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		+	Save this page/section and your new page link will appear in Red. Click it and begin editing your new page. Remember to conduct all Discussions on the Discussion page associated to every wiki page. The link is at the top, directly above the page title.
		+	</div>
		+	----
		+
	== Introduction ==		== Introduction ==
	Boot Time includes topics such as measurement, analysis, human factors, initialization techniques, and reduction techniques.		Boot Time includes topics such as measurement, analysis, human factors, initialization techniques, and reduction techniques.

@@ Line 106: / Line 106: @@
 == Articles and Presentations ==
 * "Boot Time Optimizations" - ([http://www.elinux.org/images/d/d1/Alexandre_Belloni_boottime_optimizations.pdf Slides] | [http://free-electrons.com/pub/video/2012/elce/elce-2012-belloni-boot-time-optimizations.webm Video])
-** Alexandre Belloni has presented at ELC Europe on February, 2012
+** Alexandre Belloni has presented at ELC Europe on February 20-22, 2012
 ** [http://free-electrons.com/blog/elce-2012-videos/ Main link at Free-Electrons]
 * "The Right Approach to Boot Time Reduction" - ([http://elinux.org/images/f/f7/RightApproachMinimalBootTimes.pdf Slides] | [http://www.youtube.com/watch?v=ULa4TPy7z0c YouTube Video])

@@ Line 105: / Line 105: @@
 == Articles and Presentations ==
 * "The Right Approach to Boot Time Reduction" - ([http://elinux.org/images/f/f7/RightApproachMinimalBootTimes.pdf Slides] | [http://www.youtube.com/watch?v=ULa4TPy7z0c YouTube Video])
 ** Andrew Murray has presented at ELC Europe on October 28, 2010 (Free Electrons video [http://free-electrons.com/pub/video/2010/elce/elce2010-murray-boot-time.webm here])

@@ Line 140: / Line 140: @@
 ** [http://processors.wiki.ti.com/index.php/Optimize_Linux_Boot_Time Optimize Linux Boot Time]
 ** [http://processors.wiki.ti.com/index.php/Android_Boot_Time_Optimization Android Boot Time Optimization]
-*[http://www.slideshare.net/jserv/implement-checkpointing-for-android Implement Checkpointing for Android]
+*[http://www.slideshare.net/jserv/implement-checkpointing-for-android-elce2012 Implement Checkpointing for Android]
 **Authored by Kito Cheng and Jim Huang,  [http://0xlab.org/ 0xlab]
 **Reasons to Implement Checkpointing for Android

@@ Line 137: / Line 137: @@
 **Authored by Kan-Ru Chen, [http://0xlab.org/ 0xlab]
 **This presentation covers Android boot time measurement and analysis, the proposed reduction approaches, hibernation-based technologies, and potential Android user-space optimizations.
+*Texas Instruments Embedded Processors Wiki provides the procedure to optimize Linux/Android boot time:
 === Case Studies ===

@@ Line 134: / Line 134: @@
 **Authored by M. Tim Jones for IBM Developer Works
 **This article shows you options to increase the speed with which Linux boots, including two options for parallelizing the initialization process. It also shows you how to visualize graphically the performance of the boot process.
 === Case Studies ===

@@ Line 246: / Line 246: @@
 * If you use compressed kernel, check compression algorithm. zlib is slow on decompression, and lzo is much faster. So if you implement lzo compression, you'll probably speed things up a little as well (check LKML for this). Having no compression at all may also be a good thing to try (see next topic).
-* Check to use uncompressed kernel (depends on your system configuration). Using an uncompressed kernel on a flash-based system may improve boot time. The reason is that compressed kernels are faster only when the throughput to the persistent storage is lower than the decompression throughput, and on typical embedded systems with DMA the throughput to memory outperforms the CPU-based decompression. Of course it depends on a lot of stuff like performance of flash controller, kernel storage filesystem performance, DMA controller performance, cache architecture etc. So it's individual per-system. Example: With using an uncomressed kernel (~2.8MB) uncompressing (running the uncompressor XIP in NOR flash) took ~0.5s longer than copying 2.8MB from flash to RAM.
+* Check to use uncompressed kernel (depends on your system configuration). Using an uncompressed kernel on a flash-based system may improve boot time. The reason is that compressed kernels are faster only when the throughput to the persistent storage is lower than the decompression throughput, and on typical embedded systems with DMA the throughput to memory outperforms the CPU-based decompression. Of course it depends on a lot of stuff like performance of flash controller, kernel storage filesystem performance, DMA controller performance, cache architecture etc. So it's individual per-system. Example: With using an uncompressed kernel (~2.8MB) uncompressing (running the uncompressor XIP in NOR flash) took ~0.5s longer than copying 2.8MB from flash to RAM.
 * Enable precalculated loops-per-jiffy
@@ Line 254: / Line 254: @@
 * If you use UBI: UBI is rather slow in attaching MTD devices. Everything is explained at MTD's [http://www.linux-mtd.infradead.org/doc/ubi.html#L_scalability UBI scalability] and [http://www.linux-mtd.infradead.org/doc/ubifs.html#L_scalability UBI fs scalability] sections. There is not very much you can do to speed it up but implement UBI2. UBIFS would stay intact. There were discussions about this and it does not seem to be impossibly difficult to do UBI2 ([http://www.linux-mtd.infradead.org/faq/ubi.html#L_attach_faster few ideas]).
 ** In a follow-up e-mail, Sascha Hauer wrote:
-<pre> What's interesting about this is that the kernel NAND driver is much slower
+<blockquote>"What's interesting about this is that the kernel NAND driver is much slower
 than the one in U-Boot. Looking at it it turned out that the kernel
 driver uses interrupts to wait for the controller to get ready.
 Switching this to polling nearly doubles the NAND performance. UBI
 mounts much faster now and this cuts off another few seconds from the
-boot process  :)
+boot process  :) "
-</pre>
+</blockquote>
 * Use static device nodes during boot, and later setup busybox mdev for hotplug.

← Older revision		Revision as of 06:34, 28 October 2011
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	[[Category:Boot Time]]		[[Category:Boot Time]]
	[[Category:Bootloader]]		[[Category:Bootloader]]
		+	[[Category:CE Linux Working Groups]]