Function tracing support for pstore
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b4 am 20120710001004.GA22744@lizardVersions newest first · linked by author and title
- v4 Latest8 patches 13 repliesIn review
- v37 patches 2 repliesSuperseded
- v26 patches 12 repliesSuperseded
Earlier versions · 1
| Version | Posted | Patches | Replies | Status |
|---|---|---|---|---|
| v1 | 5 patches | 5 replies | Superseded |
Patches in v4 No applies recorded yet
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/8 | tracing: Fix initialization failure path in tracing_set_tracer()kernel/ | +4 | 0 replies | |
| 2/8 | pstore: Introduce write_buf backend callbackfs/ include/ | +14 | 0 replies | |
| 3/8 | pstore: Add persistent function tracingfs/ fs/ fs/ +4 more | +208 | 17 replies | |
| 4/8 | tracing/function: Introduce persistent trace optionkernel/ | +20 | 1 reply | |
| 5/8 | pstore/ram: Convert to write_buf callbackfs/ | +9 | 0 replies | |
| 6/8 | pstore/ram: Add ftrace messages handlingDocumentation/ fs/ include/ | +59 | 0 replies | |
| 7/8 | pstore/ram: Make tracing log versionedfs/ fs/ fs/ +1 more | +17 | 9 replies | |
| 8/8 | tracing/function: Convert func_set_flag() to a switch statementkernel/ | +9 | 0 replies |
Reviews trailers per patch
1 of 8 patches has a Reviewed-by or Acked-by of their own; the series has one for all of them.
| Patch | Steven Rostedt |
|---|---|
| Series | A-b |
| 1/8 | A-b |
| 2/8 | |
| 3/8 | |
| 4/8 | |
| 5/8 | |
| 6/8 | |
| 7/8 | |
| 8/8 |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.
Cover letter [PATCH v4 0/8] Function tracing support for pstore
Hi all,
In v4:
- A few cosmetic changes in func_set_flag(), as suggested by Steven Rostedt. Firstly, in the patch that adds pstore option, I use 'else if' for the new bit (it keeps changes minimal), but then there is a new separate patch (the last in the series) that converts the whole thing into a switch construction.
In v3:
- Make traces versioned, as suggested by Steven, Tony and Colin. (The version tag is stored in the PRZ signature, see the last patch for the implementation details).
- Add Steven's Ack on the first patch.
In v2:
- Do not introduce a separate 'persistent' tracer, but introduce an option to the existing 'function' tracer.
Rationale for this patch set:
With this support kernel can save functions call chain log into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a hang or an unexpected reset (caused by, for example, a buggy driver that abuses HW).
Here's a "nano howto", to get the idea:
# mount -t debugfs debugfs /sys/kernel/debug/ # cd /sys/kernel/debug/tracing # echo function > current_tracer # echo 1 > options/func_pstore # reboot -f [...] # mount -t pstore pstore /mnt/ # tail /mnt/ftrace-ramoops 0 ffffffff8101ea64 ffffffff8101bcda native_apic_mem_read <- disconnect_bsp_APIC+0x6a/0xc0 0 ffffffff8101ea44 ffffffff8101bcf6 native_apic_mem_write <- disconnect_bsp_APIC+0x86/0xc0 0 ffffffff81020084 ffffffff8101a4b5 hpet_disable <- native_machine_shutdown+0x75/0x90 0 ffffffff81005f94 ffffffff8101a4bb iommu_shutdown_noop <- native_machine_shutdown+0x7b/0x90 0 ffffffff8101a6a1 ffffffff8101a437 native_machine_emergency_restart <- native_machine_restart+0x37/0x40 0 ffffffff811f9876 ffffffff8101a73a acpi_reboot <- native_machine_emergency_restart+0xaa/0x1e0 0 ffffffff8101a514 ffffffff8101a772 mach_reboot_fixups <- native_machine_emergency_restart+0xe2/0x1e0 0 ffffffff811d9c54 ffffffff8101a7a0 __const_udelay <- native_machine_emergency_restart+0x110/0x1e0 0 ffffffff811d9c34 ffffffff811d9c80 __delay <- __const_udelay+0x30/0x40 0 ffffffff811d9d14 ffffffff811d9c3f delay_tsc <- __delay+0xf/0x20
Mostly the code comes from trace_persistent.c driver found in the Android git tree, written by Colin Cross <[email protected]> (according to sign-off history). I reworked the driver a little bit, and ported it to pstore subsystem.
--- Documentation/ramoops.txt | 25 +++++++++ fs/pstore/Kconfig | 13 +++++ fs/pstore/Makefile | 1 + fs/pstore/ftrace.c | 35 +++++++++++++ fs/pstore/inode.c | 111 ++++++++++++++++++++++++++++++++++++++-- fs/pstore/internal.h | 43 ++++++++++++++++ fs/pstore/platform.c | 12 ++++- fs/pstore/ram.c | 65 +++++++++++++++++------ fs/pstore/ram_core.c | 12 +++-- include/linux/pstore.h | 13 +++++ include/linux/pstore_ram.h | 3 +- kernel/trace/trace.c | 7 +-- kernel/trace/trace_functions.c | 36 +++++++++---- 13 files changed, 337 insertions(+), 39 deletions(-)
Signature · 2 lines
Anton Vorontsov Email: [email protected]