From cc57165874e938ef684d71ba7d36e7088b551489 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Mon, 9 Jan 2006 20:51:41 -0800 Subject: [PATCH] kdump: dynamic per cpu allocation of memory for saving cpu registers - In case of system crash, current state of cpu registers is saved in memory in elf note format. So far memory for storing elf notes was being allocated statically for NR_CPUS. - This patch introduces dynamic allocation of memory for storing elf notes. It uses alloc_percpu() interface. This should lead to better memory usage. - Introduced based on Andi Kleen's and Eric W. Biederman's suggestions. - This patch also moves memory allocation for elf notes from architecture dependent portion to architecture independent portion. Now crash_notes is architecture independent. The whole idea is that size of memory to be allocated per cpu (MAX_NOTE_BYTES) can be architecture dependent and allocation of this memory can be architecture independent. Signed-off-by: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kexec.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'kernel') diff --git a/kernel/kexec.c b/kernel/kexec.c index 2c95848..1197de8 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -26,6 +26,9 @@ #include #include +/* Per cpu memory for storing cpu states in case of system crash. */ +note_buf_t* crash_notes; + /* Location of the reserved area for the crash kernel */ struct resource crashk_res = { .name = "Crash kernel", @@ -1060,3 +1063,16 @@ void crash_kexec(struct pt_regs *regs) xchg(&kexec_lock, 0); } } + +static int __init crash_notes_memory_init(void) +{ + /* Allocate memory for saving cpu registers. */ + crash_notes = alloc_percpu(note_buf_t); + if (!crash_notes) { + printk("Kexec: Memory allocation for saving cpu register" + " states failed\n"); + return -ENOMEM; + } + return 0; +} +module_init(crash_notes_memory_init) -- cgit v1.1