[PATCH] fix big initramfs (was: [PATCH] gen_init_cpio fixes for 2.5.64)

[Anders Gustafsson]

On Sat, Mar 08, 2003 at 10:04:52PM -0800, Greg KH wrote:
> On Sat, Mar 08, 2003 at 03:37:45PM +0100, Anders Gustafsson wrote:
> > On Fri, Mar 07, 2003 at 04:43:40PM -0800, Greg KH wrote:
> > > 
> > > ChangeSet 1.1124, 2003/03/07 16:39:06-08:00, [e-mail]
> > > 
> > > gen_init_cpio: Add the ability to add files to the cpio image.
> > 
> > Have you been able to boot the kernel with a cpio-archive that contains
> > files larger than a few k? The kernel crashes on me when writing to the file
> > in ramfs.
> 
> I have not tried that, no.
> 
> > It crashes i the third or forth flush_window or so..
> 
> What does the oops show?

The oops shows a crash in balance_dirty_pages. Or rather get_dirty_limits(),
and in get_dirty_limits() we have:

    unmapped_ratio = 100 - (ps->nr_mapped * 100) / total_pages;
    
total_pages is initialized in page_writeback_init(), which is a init-call,
called far later than populate_rootfs(). So, BOOM, division by zero.

Patch below makes the call to page_writeback_init() explicit in
start_kernel, just before populate_rootfs().

-- 
Anders Gustafsson - [e-mail] - http://0x63.nu/

You can import this changeset into BK by piping this whole message to:
'| bk receive [path to repository]' or apply the patch as usual.

===================================================================

ChangeSet@1.1102, 2003-03-12 09:14:47+01:00, [e-mail]
  Explicitly call page_writeback_init because it must be called before populate_rootfs()

 init/main.c         |    3 +++
 mm/page-writeback.c |    4 +---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff -Nru a/init/main.c b/init/main.c
--- a/init/main.c	Wed Mar 12 09:16:57 2003
+++ b/init/main.c	Wed Mar 12 09:16:57 2003
@@ -70,6 +70,7 @@
 extern void pte_chain_init(void);
 extern void radix_tree_init(void);
 extern void free_initmem(void);
+extern void page_writeback_init(void);
 extern void populate_rootfs(void);
 extern void driver_init(void);
 
@@ -429,6 +430,8 @@
 	vfs_caches_init(num_physpages);
 	radix_tree_init();
 	signals_init();
+	/* rootfs populating might need page-writeback */
+	page_writeback_init();
 	populate_rootfs();
 #ifdef CONFIG_PROC_FS
 	proc_root_init();
diff -Nru a/mm/page-writeback.c b/mm/page-writeback.c
--- a/mm/page-writeback.c	Wed Mar 12 09:16:57 2003
+++ b/mm/page-writeback.c	Wed Mar 12 09:16:57 2003
@@ -369,7 +369,7 @@
  * dirty memory thresholds: allowing too much dirty highmem pins an excessive
  * number of buffer_heads.
  */
-static int __init page_writeback_init(void)
+void __init page_writeback_init(void)
 {
 	long buffer_pages = nr_free_buffer_pages();
 	long correction;
@@ -392,9 +392,7 @@
 	add_timer(&wb_timer);
 	set_ratelimit();
 	register_cpu_notifier(&ratelimit_nb);
-	return 0;
 }
-module_init(page_writeback_init);
 
 int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {

===================================================================

This BitKeeper patch contains the following changesets:
1.1102
## Wrapped with gzip_uu ##

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