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author | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-17 16:15:55 -0500 |
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committer | Jonathan Herman <hermanjl@cs.unc.edu> | 2013-01-17 16:15:55 -0500 |
commit | 8dea78da5cee153b8af9c07a2745f6c55057fe12 (patch) | |
tree | a8f4d49d63b1ecc92f2fddceba0655b2472c5bd9 /Documentation/kdump/kdump.txt | |
parent | 406089d01562f1e2bf9f089fd7637009ebaad589 (diff) |
Patched in Tegra support.
Diffstat (limited to 'Documentation/kdump/kdump.txt')
-rw-r--r-- | Documentation/kdump/kdump.txt | 37 |
1 files changed, 4 insertions, 33 deletions
diff --git a/Documentation/kdump/kdump.txt b/Documentation/kdump/kdump.txt index 13f1aa09b93..7a9e0b4b290 100644 --- a/Documentation/kdump/kdump.txt +++ b/Documentation/kdump/kdump.txt | |||
@@ -17,8 +17,8 @@ You can use common commands, such as cp and scp, to copy the | |||
17 | memory image to a dump file on the local disk, or across the network to | 17 | memory image to a dump file on the local disk, or across the network to |
18 | a remote system. | 18 | a remote system. |
19 | 19 | ||
20 | Kdump and kexec are currently supported on the x86, x86_64, ppc64, ia64, | 20 | Kdump and kexec are currently supported on the x86, x86_64, ppc64 and ia64 |
21 | and s390x architectures. | 21 | architectures. |
22 | 22 | ||
23 | When the system kernel boots, it reserves a small section of memory for | 23 | When the system kernel boots, it reserves a small section of memory for |
24 | the dump-capture kernel. This ensures that ongoing Direct Memory Access | 24 | the dump-capture kernel. This ensures that ongoing Direct Memory Access |
@@ -34,18 +34,11 @@ Similarly on PPC64 machines first 32KB of physical memory is needed for | |||
34 | booting regardless of where the kernel is loaded and to support 64K page | 34 | booting regardless of where the kernel is loaded and to support 64K page |
35 | size kexec backs up the first 64KB memory. | 35 | size kexec backs up the first 64KB memory. |
36 | 36 | ||
37 | For s390x, when kdump is triggered, the crashkernel region is exchanged | ||
38 | with the region [0, crashkernel region size] and then the kdump kernel | ||
39 | runs in [0, crashkernel region size]. Therefore no relocatable kernel is | ||
40 | needed for s390x. | ||
41 | |||
42 | All of the necessary information about the system kernel's core image is | 37 | All of the necessary information about the system kernel's core image is |
43 | encoded in the ELF format, and stored in a reserved area of memory | 38 | encoded in the ELF format, and stored in a reserved area of memory |
44 | before a crash. The physical address of the start of the ELF header is | 39 | before a crash. The physical address of the start of the ELF header is |
45 | passed to the dump-capture kernel through the elfcorehdr= boot | 40 | passed to the dump-capture kernel through the elfcorehdr= boot |
46 | parameter. Optionally the size of the ELF header can also be passed | 41 | parameter. |
47 | when using the elfcorehdr=[size[KMG]@]offset[KMG] syntax. | ||
48 | |||
49 | 42 | ||
50 | With the dump-capture kernel, you can access the memory image, or "old | 43 | With the dump-capture kernel, you can access the memory image, or "old |
51 | memory," in two ways: | 44 | memory," in two ways: |
@@ -86,7 +79,7 @@ There is also a gitweb interface available at | |||
86 | http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git | 79 | http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git |
87 | 80 | ||
88 | More information about kexec-tools can be found at | 81 | More information about kexec-tools can be found at |
89 | http://horms.net/projects/kexec/ | 82 | http://www.kernel.org/pub/linux/utils/kernel/kexec/README.html |
90 | 83 | ||
91 | 3) Unpack the tarball with the tar command, as follows: | 84 | 3) Unpack the tarball with the tar command, as follows: |
92 | 85 | ||
@@ -298,10 +291,6 @@ Boot into System Kernel | |||
298 | The region may be automatically placed on ia64, see the | 291 | The region may be automatically placed on ia64, see the |
299 | dump-capture kernel config option notes above. | 292 | dump-capture kernel config option notes above. |
300 | 293 | ||
301 | On s390x, typically use "crashkernel=xxM". The value of xx is dependent | ||
302 | on the memory consumption of the kdump system. In general this is not | ||
303 | dependent on the memory size of the production system. | ||
304 | |||
305 | Load the Dump-capture Kernel | 294 | Load the Dump-capture Kernel |
306 | ============================ | 295 | ============================ |
307 | 296 | ||
@@ -319,8 +308,6 @@ For ppc64: | |||
319 | - Use vmlinux | 308 | - Use vmlinux |
320 | For ia64: | 309 | For ia64: |
321 | - Use vmlinux or vmlinuz.gz | 310 | - Use vmlinux or vmlinuz.gz |
322 | For s390x: | ||
323 | - Use image or bzImage | ||
324 | 311 | ||
325 | 312 | ||
326 | If you are using a uncompressed vmlinux image then use following command | 313 | If you are using a uncompressed vmlinux image then use following command |
@@ -350,8 +337,6 @@ For i386, x86_64 and ia64: | |||
350 | For ppc64: | 337 | For ppc64: |
351 | "1 maxcpus=1 noirqdistrib reset_devices" | 338 | "1 maxcpus=1 noirqdistrib reset_devices" |
352 | 339 | ||
353 | For s390x: | ||
354 | "1 maxcpus=1 cgroup_disable=memory" | ||
355 | 340 | ||
356 | Notes on loading the dump-capture kernel: | 341 | Notes on loading the dump-capture kernel: |
357 | 342 | ||
@@ -377,20 +362,6 @@ Notes on loading the dump-capture kernel: | |||
377 | dump. Hence generally it is useful either to build a UP dump-capture | 362 | dump. Hence generally it is useful either to build a UP dump-capture |
378 | kernel or specify maxcpus=1 option while loading dump-capture kernel. | 363 | kernel or specify maxcpus=1 option while loading dump-capture kernel. |
379 | 364 | ||
380 | * For s390x there are two kdump modes: If a ELF header is specified with | ||
381 | the elfcorehdr= kernel parameter, it is used by the kdump kernel as it | ||
382 | is done on all other architectures. If no elfcorehdr= kernel parameter is | ||
383 | specified, the s390x kdump kernel dynamically creates the header. The | ||
384 | second mode has the advantage that for CPU and memory hotplug, kdump has | ||
385 | not to be reloaded with kexec_load(). | ||
386 | |||
387 | * For s390x systems with many attached devices the "cio_ignore" kernel | ||
388 | parameter should be used for the kdump kernel in order to prevent allocation | ||
389 | of kernel memory for devices that are not relevant for kdump. The same | ||
390 | applies to systems that use SCSI/FCP devices. In that case the | ||
391 | "allow_lun_scan" zfcp module parameter should be set to zero before | ||
392 | setting FCP devices online. | ||
393 | |||
394 | Kernel Panic | 365 | Kernel Panic |
395 | ============ | 366 | ============ |
396 | 367 | ||