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| author | Michael Holzheu <holzheu@linux.vnet.ibm.com> | 2012-01-13 05:20:14 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-01-13 08:13:11 +0400 |
| commit | 6480e5a0923756b500634d9777ec4189492fbbfe (patch) | |
| tree | 0b1d26ce39f9b7cd28a9e82627ee837734f7c3ab /kernel | |
| parent | a3dd3323058d281abd584b15ad4c5b65064d7a61 (diff) | |
| download | linux-6480e5a0923756b500634d9777ec4189492fbbfe.tar.xz | |
kdump: add missing RAM resource in crash_shrink_memory()
When shrinking crashkernel memory using /sys/kernel/kexec_crash_size for
the newly added memory no RAM resource is created at the moment.
Example:
$ cat /proc/iomem
00000000-bfffffff : System RAM
00000000-005b7ac3 : Kernel code
005b7ac4-009743bf : Kernel data
009bb000-00a85c33 : Kernel bss
c0000000-cfffffff : Crash kernel
d0000000-ffffffff : System RAM
$ echo 0 > /sys/kernel/kexec_crash_size
$ cat /proc/iomem
00000000-bfffffff : System RAM
00000000-005b7ac3 : Kernel code
005b7ac4-009743bf : Kernel data
009bb000-00a85c33 : Kernel bss
<<-- here is System RAM missing
d0000000-ffffffff : System RAM
One result of this bug is that the memory chunk can never be set offline
using memory hotplug. With this patch I insert a new "System RAM"
resource for the released memory. Then the upper example looks like the
following:
$ echo 0 > /sys/kernel/kexec_crash_size
$ cat /proc/iomem
00000000-bfffffff : System RAM
00000000-005b7ac3 : Kernel code
005b7ac4-009743bf : Kernel data
009bb000-00a85c33 : Kernel bss
c0000000-cfffffff : System RAM <<-- new rescoure
d0000000-ffffffff : System RAM
And now I can set chunk c0000000-cfffffff offline.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kexec.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/kernel/kexec.c b/kernel/kexec.c index 20ed47ae252f..60bf181b3eae 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -1129,6 +1129,7 @@ int crash_shrink_memory(unsigned long new_size) { int ret = 0; unsigned long start, end; + struct resource *ram_res; mutex_lock(&kexec_mutex); @@ -1146,6 +1147,12 @@ int crash_shrink_memory(unsigned long new_size) goto unlock; } + ram_res = kzalloc(sizeof(*ram_res), GFP_KERNEL); + if (!ram_res) { + ret = -ENOMEM; + goto unlock; + } + start = roundup(start, KEXEC_CRASH_MEM_ALIGN); end = roundup(start + new_size, KEXEC_CRASH_MEM_ALIGN); @@ -1154,7 +1161,15 @@ int crash_shrink_memory(unsigned long new_size) if ((start == end) && (crashk_res.parent != NULL)) release_resource(&crashk_res); + + ram_res->start = end; + ram_res->end = crashk_res.end; + ram_res->flags = IORESOURCE_BUSY | IORESOURCE_MEM; + ram_res->name = "System RAM"; + crashk_res.end = end - 1; + + insert_resource(&iomem_resource, ram_res); crash_unmap_reserved_pages(); unlock: |