On Wed, May 22, 2013 at 10:57:36AM +0200, Thomas Renninger wrote:
> cgroup memory subsystem pre-allocates quite some memory at boot up.
> Example dmesg:
> allocated 469762048 bytes of page_cgroup
> please try 'cgroup_disable=memory' option if you don't want memory cgroups
>
> Due to maxcpu=1 it is by far not that much than in a productive kernel.
> It still seem to be around 4M statically as no Numa overhead exists with
> only one active CPU. It is still worth to disable cgroup memory
> pre-allocating in crash kernel environment.
>
> Signed-off-by: Thomas Renninger <trenn at suse.de>
> Signed-off-by: Thomas Renninger <Thomas Renninger" trenn at suse.de>
I'm not really sure this kind of logic should be hard-coded into
kexec-tools. --append should allow callers of kexec to add this
option if it is appropriate.
> ---
> kexec/arch/i386/crashdump-x86.c | 22 ++++++++++++++++++++++
> 1 files changed, 22 insertions(+), 0 deletions(-)
>
> diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> index 7fd1c5b..e6d60a9 100644
> --- a/kexec/arch/i386/crashdump-x86.c
> +++ b/kexec/arch/i386/crashdump-x86.c
> @@ -757,6 +757,23 @@ static int cmdline_add_elfcorehdr(char *cmdline, unsigned long addr)
> return 0;
> }
>
> +static void cmdline_disable_cgroup(char *cmdline)
> +{
> + int cmdlen;
> + char str[30] = " cgroup_disable=memory";
> +
> + cmdlen = strlen(cmdline) + strlen(str);
> + if (cmdlen > (COMMAND_LINE_SIZE - 1)) {
> + /* Not fatal if cgroup memory is not disabled */
> + dbgprintf(
> + "Command line overflow, cgroup memory not disabled\n");
> + return;
> + }
> + strcat(cmdline, str);
> +
> + dbgprintf("Command line after adding adding cgroup_disable=memory\n");
> + dbgprintf("%s\n", cmdline);
> +}
>
> /*
> * This routine is specific to i386 architecture to maintain the
> @@ -1037,6 +1054,11 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> end = mem_range[i].end;
> cmdline_add_memmap_acpi(mod_cmdline, start, end);
> }
> + /*
> + * Always add disabling cgroup_diable=memory param at the end,
> + * it's not critical if it falls off
> + */
> + cmdline_disable_cgroup(mod_cmdline);
> return 0;
> }
>
> --
> 1.7.6.1
>
>
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>
