lkml.org 
[lkml]   [2006]   [Sep]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectHow does the handover from boot allocator to real allocator work
Hi Ingo,

I'm digging around trying to work out how the handover from the
boot-time allocator to the real memory management works.

I'm missing something important though: bootmem.c:free_all_bootmem()
seems to end up just putting all low memory on the freelists. How does
this not put the kernel text+data pages on the freelists? Also,
presumably things allocated in the bootmem allocator remain allocated
for the life of the running kernel?

I'm having a problem in my Xen kernel, in which free_init_pages() ends
up getting a bad_page() warning because pfn 1024 has the PG_buddy bit
set on it, which was unexpected (this page ends up being in the middle
of the initdata section). Page 1024 gets PF_buddy set by
free_all_bootmem_core(), and it becomes an order 10 page.

I presume this is broken because free_all_bootmem_core() shouldn't be
putting the kernel text+data into the freelists, but I don't see how
this is prevented in the normal i386 case. I'm guessing it's done by
something like reserve_bootmem(), but I don't see such a call which
would reserve the kernel itself.

What am I missing?

Thanks,
J
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-09-15 23:11    [W:0.042 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site