From 1bc7bc7649fa29d95c98f6a6d8dd2f08734a865c Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 23 Mar 2021 11:01:10 +0100 Subject: crashdump/x86: increase CRASH_MAX_MEMORY_RANGES to 32k virtio-mem in Linux adds/removes individual memory blocks (e.g., 128 MB each). Linux merges adjacent memory blocks added by virtio-mem devices, but we can still end up with a very sparse memory layout when unplugging memory in corner cases. Let's increase the maximum number of crash memory ranges from ~2k to 32k. 32k should be sufficient for a very long time. e_phnum field in the header is 16 bits wide, so we can fit a maximum of ~64k entries in there, shared with other entries (i.e., CPU). Therefore, using up to 32k memory ranges is fine. (if we ever need more than ~64k, we can switch to the sh_info field) Move the temporary xen ranges off the stack, dynamically allocating memory for them. Note: We don't have to increase MAX_MEMORY_RANGES, because virtio-mem added memory is driver managed and always detected and added by a driver in the kexec'ed kernel; for ordinary kexec, we must not expose these ranges in the firmware-provided memmap. Cc: Simon Horman Signed-off-by: David Hildenbrand Signed-off-by: Simon Horman --- kexec/arch/i386/crashdump-x86.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kexec/arch/i386/crashdump-x86.h') diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h index e4fdc82..479a549 100644 --- a/kexec/arch/i386/crashdump-x86.h +++ b/kexec/arch/i386/crashdump-x86.h @@ -22,7 +22,8 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline, #define X86_64_KERNEL_TEXT_SIZE (512UL*1024*1024) #define CRASH_MAX_MEMMAP_NR 1024 -#define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2) + +#define CRASH_MAX_MEMORY_RANGES 32768 /* Backup Region, First 640K of System RAM. */ #define BACKUP_SRC_START 0x00000000 -- cgit