From 56425306517ef28a9b480161cdb96d182172bc1d Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Sun, 25 Sep 2005 16:46:57 -0700 Subject: [SPARC64]: Add CONFIG_DEBUG_PAGEALLOC support. The trick is that we do the kernel linear mapping TLB miss starting with an instruction sequence like this: ba,pt %xcc, kvmap_load xor %g2, %g4, %g5 succeeded by an instruction sequence which performs a full page table walk starting at swapper_pg_dir. We first take over the trap table from the firmware. Then, using this constant PTE generation for the linear mapping area above, we build the kernel page tables for the linear mapping. After this is setup, we patch that branch above into a "nop", which will cause TLB misses to fall through to the full page table walk. With this, the page unmapping for CONFIG_DEBUG_PAGEALLOC is trivial. Signed-off-by: David S. Miller --- arch/sparc64/Kconfig.debug | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/sparc64/Kconfig.debug') diff --git a/arch/sparc64/Kconfig.debug b/arch/sparc64/Kconfig.debug index af0e9411b83..fa06ea04837 100644 --- a/arch/sparc64/Kconfig.debug +++ b/arch/sparc64/Kconfig.debug @@ -33,6 +33,14 @@ config DEBUG_BOOTMEM depends on DEBUG_KERNEL bool "Debug BOOTMEM initialization" +config DEBUG_PAGEALLOC + bool "Page alloc debugging" + depends on DEBUG_KERNEL && !SOFTWARE_SUSPEND + help + Unmap pages from the kernel linear mapping after free_pages(). + This results in a large slowdown, but helps to find certain types + of memory corruptions. + config MCOUNT bool depends on STACK_DEBUG -- cgit v1.2.3-18-g5258