Commit 0a7b35cb authored by Michael Neuling's avatar Michael Neuling Committed by Linus Torvalds
Browse files

[PATCH] Add retain_initrd boot option 



Add retain_initrd option to control freeing of initrd memory after
extraction.  By default, free memory as previously.

The first boot will need to hold a copy of the in memory fs for the second
boot.  This image can be large (much larger than the kernel), hence we can
save time when the memory loader is slow.  Also, it reduces the memory
footprint while extracting the first boot since you don't need another copy
of the fs.

Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 70e84049

Documentation/kernel-parameters.txt

+2 −0
Original line number Diff line number Diff line
@@ -1396,6 +1396,8 @@ and is between 256 and 4096 characters. It is defined in the file 
			in <PAGE_SIZE> units (needed only for swap files).

			See  Documentation/power/swsusp-and-swap-files.txt



	retain_initrd	[RAM] Keep initrd memory after extraction



	rhash_entries=	[KNL,NET]

			Set number of hash buckets for route cache

init/initramfs.c

+16 −1
Original line number Diff line number Diff line
@@ -491,6 +491,17 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only) 
	return message;

}



static int __initdata do_retain_initrd;



static int __init retain_initrd_param(char *str)

{

	if (*str)

		return 0;

	do_retain_initrd = 1;

	return 1;

}

__setup("retain_initrd", retain_initrd_param);



extern char __initramfs_start[], __initramfs_end[];

#ifdef CONFIG_BLK_DEV_INITRD

#include <linux/initrd.h>
@@ -501,7 +512,11 @@ static void __init free_initrd(void) 
#ifdef CONFIG_KEXEC

	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);

	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);

#endif

	if (do_retain_initrd)

		goto skip;



#ifdef CONFIG_KEXEC

	/*

	 * If the initrd region is overlapped with crashkernel reserved region,

	 * free only memory that is not part of crashkernel region.
@@ -519,7 +534,7 @@ static void __init free_initrd(void) 
	} else

#endif

		free_initrd_mem(initrd_start, initrd_end);



skip:

	initrd_start = 0;

	initrd_end = 0;

}

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