mm: introduce common help functions to deal with reserved/managed pages
The original goal of this patchset is to fix the bug reported by
https://bugzilla.kernel.org/show_bug.cgi?id=53501
Now it has also been expanded to reduce common code used by memory
initializion.
This is the first part, which applies to v3.9-rc1.
It introduces following common helper functions to simplify
free_initmem() and free_initrd_mem() on different architectures:
adjust_managed_page_count():
will be used to adjust totalram_pages, totalhigh_pages,
zone->managed_pages when reserving/unresering a page.
__free_reserved_page():
free a reserved page into the buddy system without adjusting
page statistics info
free_reserved_page():
free a reserved page into the buddy system and adjust page
statistics info
mark_page_reserved():
mark a page as reserved and adjust page statistics info
free_reserved_area():
free a continous ranges of pages by calling free_reserved_page()
free_initmem_default():
default method to free __init pages.
We have only tested these patchset on x86 platforms, and have done basic
compliation tests using cross-compilers from ftp.kernel.org. That means
some code may not pass compilation on some architectures. So any help to
test this patchset are welcomed!
There are several other parts still under development:
Part2: introduce free_highmem_page() to simplify freeing highmem pages
Part3: refine code to manage totalram_pages, totalhigh_pages and
zone->managed_pages
Part4: introduce helper functions to simplify mem_init() and remove the
global variable num_physpages.
This patch:
Code to deal with reserved/managed pages are duplicated by many
architectures, so introduce common help functions to reduce duplicated
code. These common help functions will also be used to concentrate code
to modify totalram_pages and zone->managed_pages, which makes the code
much more clear.
Signed-off-by: Jiang Liu <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: Anatolij Gustschin <[email protected]>
Cc: Aurelien Jacquiot <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Chen Liqin <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: David Howells <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Guan Xuetao <[email protected]>
Cc: Haavard Skinnemoen <[email protected]>
Cc: Hans-Christian Egtvedt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: James Hogan <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Jonas Bonn <[email protected]>
Cc: Koichi Yasutake <[email protected]>
Cc: Lennox Wu <[email protected]>
Cc: Mark Salter <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Max Filippov <[email protected]>
Cc: Michal Simek <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: Mike Frysinger <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Russell King <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: Vineet Gupta <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Zhang Yanfei <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index da7a2fe..5c660f5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5121,6 +5121,26 @@
#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+unsigned long free_reserved_area(unsigned long start, unsigned long end,
+ int poison, char *s)
+{
+ unsigned long pages, pos;
+
+ pos = start = PAGE_ALIGN(start);
+ end &= PAGE_MASK;
+ for (pages = 0; pos < end; pos += PAGE_SIZE, pages++) {
+ if (poison)
+ memset((void *)pos, poison, PAGE_SIZE);
+ free_reserved_page(virt_to_page(pos));
+ }
+
+ if (pages && s)
+ pr_info("Freeing %s memory: %ldK (%lx - %lx)\n",
+ s, pages << (PAGE_SHIFT - 10), start, end);
+
+ return pages;
+}
+
/**
* set_dma_reserve - set the specified number of pages reserved in the first zone
* @new_dma_reserve: The number of pages to mark reserved
