Subject: slower decompress?

From: Chris Blazie <[email-masked]>
Date: Wed, 16 Aug 2000 11:11:36 -0400 (EDT)

Hi,
	I just upgraded the kernel for our SA-1110 (custom) board from
2.3.99-pre3 to 2.4.0-test6-rmk2-np1.  I've noticed that decompressing
takes much longer than it used to (5-10 times longer).  Is there a change
in mmu or icache setup I'm missing?

Thanks,
Chris

unsubscribe: body of `unsubscribe linux-arm-kernel' to [email-masked]

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From: Nicolas Pitre <[email-masked]>
Date: Wed, 16 Aug 2000 11:36:05 -0400 (EDT)

> in mmu or icache setup I'm missing?

See the end of linux/arch/arm/boot/compressed/head-sa1100.S:

/*
 * Pause for a short time so that we give enough time
 * for the host to start a terminal up.
 */
                mov     r0, #0x00200000
1:              subs    r0, r0, #1
                bne     1b

Try removing that code completely.

Nicolas

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From: Russell King - ARM Linux Admin <[email-masked]>
Date: Wed, 16 Aug 2000 18:30:19 +0100 (BST)

> in mmu or icache setup I'm missing?

There is currently code at the bottom of arch/arm/boot/compressed/head-sa1100.S
to add a 1 second delay before decompression starts.  This is so that the
boot messages are actually readable when you use angelboot+minicom.
   _____
  |_____| ------------------------------------------------- ---+---+-
  |   |        Russell King       [email-masked]      --- ---
  | | | |            http://www.arm.linux.org.uk/            /  /  |
  | +-+-+                                                     --- -+-
  /   |               THE developer of ARM Linux              |+| /|\
 /  | | |                                                     ---  |
    +-+-+ -------------------------------------------------  /\\\  |

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From: Chris Blazie <[email-masked]>
Date: Wed, 16 Aug 2000 15:13:11 -0400 (EDT)

> boot messages are actually readable when you use angelboot+minicom.

	I saw that and removed it as Nicolas suggested.  But the actual
decompression itself (i.e. after Uncompressing Linux......) is where the
real problem is.  I just re-checked with an older kernel, and it
decompresses in less than a second.  The 2.4.0-test6 kernel takes 10-15
seconds.  Something is definitely not getting set up right in my case.
I'll try to pin down the changes from pre3.

Thanks,
Chris

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From: Nicolas Pitre <[email-masked]>
Date: Wed, 16 Aug 2000 16:43:02 -0400 (EDT)

> seconds.  Something is definitely not getting set up right in my case.

Are the dots from the "Uncompressing Linux ..." banner actually appearing
at a slow pace, or is the boot process stalling for a while after all dots
appeared?

Nicolas

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From: Chris Blazie <[email-masked]>
Date: Thu, 17 Aug 2000 08:59:08 -0400 (EDT)

> at a slow pace, or is the boot process stalling for a while after all dots

	The dots are appearing at a slow pace.  What should the status of
the mmu and icache be when decompress_kernel is called?

Chris

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From: Nicolas Pitre <[email-masked]>
Date: Sat, 19 Aug 2000 11:49:59 -0400 (EDT)

> the mmu and icache be when decompress_kernel is called?

MMU, i-cache and d-cache are actually enabled for decompression speed in
linux/arch/arm/compressed/head.S.

Just tried it again on my Assabet and everything looks OK here.
What bogomips number do you get?

Nicolas

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From: Chris Blazie <[email-masked]>
Date: Tue, 22 Aug 2000 09:09:57 -0400 (EDT)

> What bogomips number do you get?

	I'm getting 124.52 bogomips.  Sound about right?

Chris

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From: Nicolas Pitre <[email-masked]>
Date: Tue, 22 Aug 2000 09:43:47 -0400 (EDT)

> 	I'm getting 124.52 bogomips.  Sound about right?

For a 133MHz part, yes.

Nicolas