[lkml]   [2009]   [Mar]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [crash] Re: Latest brk patchset
Jeremy Fitzhardinge wrote:
> Yinghai Lu wrote:
>> could be max_pfn_mapped change in head_32.S that reduce mapping range
>> to _end only.
> Yes, I would say you're right. Trimming the mapping to _end only leaves
> the space under the kernel avaliable for allocating pagetable from e820
> space. In this case we've got DEBUG_PAGEALLOC enabled, which inhibits
> the use of PSE, and BIOS corruption checking on, which eats a chunk of
> low memory. In combination, there's only 0x8f000 bytes free below the
> kernel, and it needs 0xe1000 to allocate for pagetables.
> Reverting 2bd2753ff46346543ab92e80df9d96366e21baa5 fixes the problem for
> me, though it does result in a kernel with a 73MB BSS...

I did kind of think that was a bit fishy, but I somehow assumed you'd
taken the consequences into account. Obviously not.

The 73 MB brk isn't a problem per se as it will not be used in most
systems. This, in fact, is the whole reason for using brk and not just
bss: it allows unused brk to be reclaimed at a relatively early stage.


 \ /
  Last update: 2009-03-16 19:23    [W:0.117 / U:3.176 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site