Re: Highmemory Problem with RHEL3 .... 2.4.21-5.ELsmp

[Fawad Lateef <fawadlateef@gmail.com>]

On 8/8/05, Zachary Amsden <zach@vmware.com> wrote:
> 
> IIRC 2.4.21 has some highmem bugs that have since been fixed.  But, it
> sounds like you might be doing something quite unusual.  Code would
> definitely give people a better idea of what might be wrong.  

I think you overlooked what i mentioned in P.S. ; which is 

My memory reservation and later using that memory through kmap_atomic
works well on the kernels other than RHEL3 2.4.21-e.ELsmp
.............. the page reservation was done in the
arch/i386/mm/init.c file in function one_highpage_init ...... I have
Machine with 16GB RAM and 2 - Xeon 2.4GHz Processors .....

The code which I added for memory reservation in kernel is : 

void __init one_highpage_init(struct page *page, int pfn, int bad_ppro)
{
	if (!page_is_ram(pfn)) {
		SetPageReserved(page);
		return;
	}
	
	if (bad_ppro && page_kills_ppro(pfn)) {
		SetPageReserved(page);
		return;
	}

// Here's the code which i added for memory reservation ..... i m
setting 0xC4 in page->count just because i will know later that these
pages have been reserved by me ... not by kernel .....

	if ((unsigned long)(page - mem_map) > 0x80000) {
		SetPageReserved(page);
		set_bit(PG_highmem, &page->flags);
		atomic_set(&page->count, 0xC4);
		totalhigh_pages++;
		return;
	}

// My code Ends here 
	
	ClearPageReserved(page);
	set_bit(PG_highmem, &page->flags);
	atomic_set(&page->count, 1);
	__free_page(page);
	totalhigh_pages++;
}


After this in my module, i simply use kmap_atomic to map the page
reserved by me and tried to use that ........ its working perfect in
both 2.4.x series and also working in 2.6.x .....

> You should definitely consider moving to 2.6 to get a better response.
> 

i already moved to 2.6.x already !!! but the current requiment is to
use RHEL3 Kernel which is 2.4.21-27.ELsmp

I think its now more clear !!!! waiting for your resposes !!!


-- 
Fawad Lateef