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: Michael Neuling <[email protected]>
---
Removed unnecessary init of do_retain_initrd as suggested by Randy
Dunlap.
Documentation/kernel-parameters.txt | 2 ++
init/initramfs.c | 18 ++++++++++++++++--
2 files changed, 18 insertions(+), 2 deletions(-)
Index: linux-2.6-ozlabs/Documentation/kernel-parameters.txt
===================================================================
--- linux-2.6-ozlabs.orig/Documentation/kernel-parameters.txt
+++ linux-2.6-ozlabs/Documentation/kernel-parameters.txt
@@ -1366,6 +1366,8 @@ and is between 256 and 4096 characters.
resume= [SWSUSP]
Specify the partition device for software suspend
+ retain_initrd [RAM] Keep initrd memory after extraction
+
rhash_entries= [KNL,NET]
Set number of hash buckets for route cache
Index: linux-2.6-ozlabs/init/initramfs.c
===================================================================
--- linux-2.6-ozlabs.orig/init/initramfs.c
+++ linux-2.6-ozlabs/init/initramfs.c
@@ -487,6 +487,17 @@ static char * __init unpack_to_rootfs(ch
return message;
}
+static int 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>
@@ -494,10 +505,13 @@ extern char __initramfs_start[], __initr
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);
+ 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.
@@ -515,7 +529,7 @@ static void __init free_initrd(void)
} else
#endif
free_initrd_mem(initrd_start, initrd_end);
-
+skip:
initrd_start = 0;
initrd_end = 0;
}
Michael Neuling wrote:
> 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: Michael Neuling <[email protected]>
> ---
> Removed unnecessary init of do_retain_initrd as suggested by Randy
> Dunlap.
>
> Documentation/kernel-parameters.txt | 2 ++
> init/initramfs.c | 18 ++++++++++++++++--
> 2 files changed, 18 insertions(+), 2 deletions(-)
>
> Index: linux-2.6-ozlabs/Documentation/kernel-parameters.txt
> ===================================================================
> --- linux-2.6-ozlabs.orig/Documentation/kernel-parameters.txt
> +++ linux-2.6-ozlabs/Documentation/kernel-parameters.txt
> @@ -1366,6 +1366,8 @@ and is between 256 and 4096 characters.
> resume= [SWSUSP]
> Specify the partition device for software suspend
>
> + retain_initrd [RAM] Keep initrd memory after extraction
> +
> rhash_entries= [KNL,NET]
> Set number of hash buckets for route cache
>
> Index: linux-2.6-ozlabs/init/initramfs.c
> ===================================================================
> --- linux-2.6-ozlabs.orig/init/initramfs.c
> +++ linux-2.6-ozlabs/init/initramfs.c
> @@ -487,6 +487,17 @@ static char * __init unpack_to_rootfs(ch
> return message;
> }
>
> +static int 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>
> @@ -494,10 +505,13 @@ extern char __initramfs_start[], __initr
>
> 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);
I'm still not seeing how using crashk_res is valid here when
CONFIG_KEXEC=n. Can you explain that, please?
You did test this with KEXEC=y and KEXEC=n, right?
> + 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.
> @@ -515,7 +529,7 @@ static void __init free_initrd(void)
> } else
> #endif
> free_initrd_mem(initrd_start, initrd_end);
> -
> +skip:
> initrd_start = 0;
> initrd_end = 0;
> }
--
~Randy
> > -#ifdef CONFIG_KEXEC
> > unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
> > unsigned long crashk_end = (unsigned long)__va(crashk_res.end);
>
> I'm still not seeing how using crashk_res is valid here when
> CONFIG_KEXEC=n. Can you explain that, please?
> You did test this with KEXEC=y and KEXEC=n, right?
Yeah, you'd think I would but apparently not. Sorry, re-sending.
Mikey