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authorVivek Goyal <vgoyal@in.ibm.com>2006-01-09 23:51:41 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-01-10 11:01:26 -0500
commitcc57165874e938ef684d71ba7d36e7088b551489 (patch)
treee1847f5547a7a426214e9ef0719eab908ee305d7
parent82409411571ad89d271dc46f7fa26149fad9efdf (diff)
[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 <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/i386/kernel/crash.c5
-rw-r--r--arch/ppc/kernel/machine_kexec.c6
-rw-r--r--arch/s390/kernel/crash.c2
-rw-r--r--arch/x86_64/kernel/crash.c2
-rw-r--r--include/asm-i386/kexec.h3
-rw-r--r--include/asm-powerpc/kexec.h3
-rw-r--r--include/asm-s390/kexec.h3
-rw-r--r--include/asm-x86_64/kexec.h3
-rw-r--r--include/linux/kexec.h2
-rw-r--r--kernel/kexec.c16
10 files changed, 21 insertions, 24 deletions
diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c
index 10fe6569751e..f1e65c2ead6e 100644
--- a/arch/i386/kernel/crash.c
+++ b/arch/i386/kernel/crash.c
@@ -25,7 +25,6 @@
25#include <mach_ipi.h> 25#include <mach_ipi.h>
26 26
27 27
28note_buf_t crash_notes[NR_CPUS];
29/* This keeps a track of which one is crashing cpu. */ 28/* This keeps a track of which one is crashing cpu. */
30static int crashing_cpu; 29static int crashing_cpu;
31 30
@@ -72,7 +71,9 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
72 * squirrelled away. ELF notes happen to provide 71 * squirrelled away. ELF notes happen to provide
73 * all of that that no need to invent something new. 72 * all of that that no need to invent something new.
74 */ 73 */
75 buf = &crash_notes[cpu][0]; 74 buf = (u32*)per_cpu_ptr(crash_notes, cpu);
75 if (!buf)
76 return;
76 memset(&prstatus, 0, sizeof(prstatus)); 77 memset(&prstatus, 0, sizeof(prstatus));
77 prstatus.pr_pid = current->pid; 78 prstatus.pr_pid = current->pid;
78 elf_core_copy_regs(&prstatus.pr_reg, regs); 79 elf_core_copy_regs(&prstatus.pr_reg, regs);
diff --git a/arch/ppc/kernel/machine_kexec.c b/arch/ppc/kernel/machine_kexec.c
index a882b0dbe8de..84d65a87191e 100644
--- a/arch/ppc/kernel/machine_kexec.c
+++ b/arch/ppc/kernel/machine_kexec.c
@@ -28,12 +28,6 @@ typedef NORET_TYPE void (*relocate_new_kernel_t)(
28const extern unsigned char relocate_new_kernel[]; 28const extern unsigned char relocate_new_kernel[];
29const extern unsigned int relocate_new_kernel_size; 29const extern unsigned int relocate_new_kernel_size;
30 30
31/*
32 * Provide a dummy crash_notes definition while crash dump arrives to ppc.
33 * This prevents breakage of crash_notes attribute in kernel/ksysfs.c.
34 */
35note_buf_t crash_notes[NR_CPUS];
36
37void machine_shutdown(void) 31void machine_shutdown(void)
38{ 32{
39 if (ppc_md.machine_shutdown) 33 if (ppc_md.machine_shutdown)
diff --git a/arch/s390/kernel/crash.c b/arch/s390/kernel/crash.c
index 7bd169c58b0c..926cceeae0fa 100644
--- a/arch/s390/kernel/crash.c
+++ b/arch/s390/kernel/crash.c
@@ -10,8 +10,6 @@
10#include <linux/threads.h> 10#include <linux/threads.h>
11#include <linux/kexec.h> 11#include <linux/kexec.h>
12 12
13note_buf_t crash_notes[NR_CPUS];
14
15void machine_crash_shutdown(struct pt_regs *regs) 13void machine_crash_shutdown(struct pt_regs *regs)
16{ 14{
17} 15}
diff --git a/arch/x86_64/kernel/crash.c b/arch/x86_64/kernel/crash.c
index 535e04466079..efe450760bbc 100644
--- a/arch/x86_64/kernel/crash.c
+++ b/arch/x86_64/kernel/crash.c
@@ -19,8 +19,6 @@
19#include <asm/nmi.h> 19#include <asm/nmi.h>
20#include <asm/hw_irq.h> 20#include <asm/hw_irq.h>
21 21
22note_buf_t crash_notes[NR_CPUS];
23
24void machine_crash_shutdown(struct pt_regs *regs) 22void machine_crash_shutdown(struct pt_regs *regs)
25{ 23{
26 /* This function is only called after the system 24 /* This function is only called after the system
diff --git a/include/asm-i386/kexec.h b/include/asm-i386/kexec.h
index 6ed2a03e37b3..d80d446498fb 100644
--- a/include/asm-i386/kexec.h
+++ b/include/asm-i386/kexec.h
@@ -26,8 +26,5 @@
26#define KEXEC_ARCH KEXEC_ARCH_386 26#define KEXEC_ARCH KEXEC_ARCH_386
27 27
28#define MAX_NOTE_BYTES 1024 28#define MAX_NOTE_BYTES 1024
29typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
30
31extern note_buf_t crash_notes[];
32 29
33#endif /* _I386_KEXEC_H */ 30#endif /* _I386_KEXEC_H */
diff --git a/include/asm-powerpc/kexec.h b/include/asm-powerpc/kexec.h
index 4263af3cadfd..e363752276ef 100644
--- a/include/asm-powerpc/kexec.h
+++ b/include/asm-powerpc/kexec.h
@@ -38,9 +38,6 @@
38#ifdef CONFIG_KEXEC 38#ifdef CONFIG_KEXEC
39 39
40#define MAX_NOTE_BYTES 1024 40#define MAX_NOTE_BYTES 1024
41typedef u32 note_buf_t[MAX_NOTE_BYTES / sizeof(u32)];
42
43extern note_buf_t crash_notes[];
44 41
45#ifdef __powerpc64__ 42#ifdef __powerpc64__
46extern void kexec_smp_wait(void); /* get and clear naca physid, wait for 43extern void kexec_smp_wait(void); /* get and clear naca physid, wait for
diff --git a/include/asm-s390/kexec.h b/include/asm-s390/kexec.h
index 54cf7d9f251c..b4809d98fe69 100644
--- a/include/asm-s390/kexec.h
+++ b/include/asm-s390/kexec.h
@@ -35,8 +35,5 @@
35#define KEXEC_ARCH KEXEC_ARCH_S390 35#define KEXEC_ARCH KEXEC_ARCH_S390
36 36
37#define MAX_NOTE_BYTES 1024 37#define MAX_NOTE_BYTES 1024
38typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
39
40extern note_buf_t crash_notes[];
41 38
42#endif /*_S390_KEXEC_H */ 39#endif /*_S390_KEXEC_H */
diff --git a/include/asm-x86_64/kexec.h b/include/asm-x86_64/kexec.h
index 42d2ff15c592..cea78543a574 100644
--- a/include/asm-x86_64/kexec.h
+++ b/include/asm-x86_64/kexec.h
@@ -26,8 +26,5 @@
26#define KEXEC_ARCH KEXEC_ARCH_X86_64 26#define KEXEC_ARCH KEXEC_ARCH_X86_64
27 27
28#define MAX_NOTE_BYTES 1024 28#define MAX_NOTE_BYTES 1024
29typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
30
31extern note_buf_t crash_notes[];
32 29
33#endif /* _X86_64_KEXEC_H */ 30#endif /* _X86_64_KEXEC_H */
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index c8468472aec0..c1cd9b31159e 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -125,6 +125,8 @@ extern struct kimage *kexec_image;
125/* Location of a reserved region to hold the crash kernel. 125/* Location of a reserved region to hold the crash kernel.
126 */ 126 */
127extern struct resource crashk_res; 127extern struct resource crashk_res;
128typedef u32 note_buf_t[MAX_NOTE_BYTES/4];
129extern note_buf_t *crash_notes;
128 130
129#else /* !CONFIG_KEXEC */ 131#else /* !CONFIG_KEXEC */
130struct pt_regs; 132struct pt_regs;
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 2c95848fbce8..1197de8b2a94 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -26,6 +26,9 @@
26#include <asm/system.h> 26#include <asm/system.h>
27#include <asm/semaphore.h> 27#include <asm/semaphore.h>
28 28
29/* Per cpu memory for storing cpu states in case of system crash. */
30note_buf_t* crash_notes;
31
29/* Location of the reserved area for the crash kernel */ 32/* Location of the reserved area for the crash kernel */
30struct resource crashk_res = { 33struct resource crashk_res = {
31 .name = "Crash kernel", 34 .name = "Crash kernel",
@@ -1060,3 +1063,16 @@ void crash_kexec(struct pt_regs *regs)
1060 xchg(&kexec_lock, 0); 1063 xchg(&kexec_lock, 0);
1061 } 1064 }
1062} 1065}
1066
1067static int __init crash_notes_memory_init(void)
1068{
1069 /* Allocate memory for saving cpu registers. */
1070 crash_notes = alloc_percpu(note_buf_t);
1071 if (!crash_notes) {
1072 printk("Kexec: Memory allocation for saving cpu register"
1073 " states failed\n");
1074 return -ENOMEM;
1075 }
1076 return 0;
1077}
1078module_init(crash_notes_memory_init)