kexec: allocate the kexec control page with KEXEC_CONTROL_MEMORY_GFP (7e01b5ac) · Commits · 戴 / test

Introduce KEXEC_CONTROL_MEMORY_GFP to allow the architecture code to override the gfp flags of the allocation for the kexec control page. The loop in kimage_alloc_normal_control_pages allocates pages with GFP_KERNEL until a page is found that happens to have an address smaller than the KEXEC_CONTROL_MEMORY_LIMIT. On systems with a large memory size but a small KEXEC_CONTROL_MEMORY_LIMIT the loop will keep allocating memory until the oom killer steps in. Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/kexec.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,9 @@
		/* Not more than 2GB */
		#define KEXEC_CONTROL_MEMORY_LIMIT (1UL<<31)

		/* Allocate control page with GFP_DMA */
		#define KEXEC_CONTROL_MEMORY_GFP GFP_DMA

		/* Maximum address we can use for the crash control pages */
		#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT (-1UL)

include/linux/kexec.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,10 @@
		#error KEXEC_CONTROL_MEMORY_LIMIT not defined
		#endif

		#ifndef KEXEC_CONTROL_MEMORY_GFP
		#define KEXEC_CONTROL_MEMORY_GFP GFP_KERNEL
		#endif

		#ifndef KEXEC_CONTROL_PAGE_SIZE
		#error KEXEC_CONTROL_PAGE_SIZE not defined
		#endif

kernel/kexec.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -707,7 +707,7 @@ static struct page kimage_alloc_normal_control_pages(struct kimage image,
		do {
		unsigned long pfn, epfn, addr, eaddr;

		pages = kimage_alloc_pages(GFP_KERNEL, order);
		pages = kimage_alloc_pages(KEXEC_CONTROL_MEMORY_GFP, order);
		if (!pages)
		break;
		pfn = page_to_pfn(pages);

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