Re: Reboot while booting with new per-CPU allocator

From: Robert Watson <rwatson_at_FreeBSD.org>
Date: Thu, 16 Jun 2005 18:44:18 +0100 (BST)
On Thu, 16 Jun 2005, Stephane E. Potvin wrote:

>>> I did a binary search to find the offending commit. Reverting the changes
>>> to kern_malloc.c and malloc.h locally did fix the problem. That's what
>>> I'm
>>> currently using to type this message. I also had to revert the changes to
>>> vmstat to make the world compile.
>>>
>>> Using head sources from yesterday (Jun 15) exhibit the same problem
>>> unfortunately.
>>
>> Hmm..  It looks like Alan Cox just committed the attached patch to
>> uma_int.h to modify UMA_BOOT_PAGES following a report of a panic at a
>> similar point in the boot process.  Could you try updating to the latest
>> uma_int.h or trying the patch below to see if it makes a difference?
>>
>
> Great :) It did the trick. The laptop is happily booting with the new 
> allocator now. Thanks a lot to you and Alan Cox.

Looks like what basically happened is this these kern_malloc.c changes 
increase the memory burden on UMA as statistics structures for malloc 
types now get allocated from UMA.  It looks like, from your dmesg, you 
have a fair number of modules loaded, so the storage for the statistics 
comes out of the early UMA page pool, whereas before it came out of BSS. 
We'll see if further tuning is required or not with large numbers of 
modules.  The thing that surprised me, though, is the unclean failure 
mode.  The other report saw a clean panic which presumably made debugging 
it much easier...

Robert N M Watson
Received on Thu Jun 16 2005 - 15:42:05 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:36 UTC