1 2config PRINTK_TIME 3 bool "Show timing information on printks" 4 depends on PRINTK 5 help 6 Selecting this option causes timing information to be 7 included in printk output. This allows you to measure 8 the interval between kernel operations, including bootup 9 operations. This is useful for identifying long delays 10 in kernel startup. 11 12config ENABLE_WARN_DEPRECATED 13 bool "Enable __deprecated logic" 14 default y 15 help 16 Enable the __deprecated logic in the kernel build. 17 Disable this to suppress the "warning: 'foo' is deprecated 18 (declared at kernel/power/somefile.c:1234)" messages. 19 20config ENABLE_MUST_CHECK 21 bool "Enable __must_check logic" 22 default y 23 help 24 Enable the __must_check logic in the kernel build. Disable this to 25 suppress the "warning: ignoring return value of 'foo', declared with 26 attribute warn_unused_result" messages. 27 28config FRAME_WARN 29 int "Warn for stack frames larger than (needs gcc 4.4)" 30 range 0 8192 31 default 1024 if !64BIT 32 default 2048 if 64BIT 33 help 34 Tell gcc to warn at build time for stack frames larger than this. 35 Setting this too low will cause a lot of warnings. 36 Setting it to 0 disables the warning. 37 Requires gcc 4.4 38 39config MAGIC_SYSRQ 40 bool "Magic SysRq key" 41 depends on !UML 42 help 43 If you say Y here, you will have some control over the system even 44 if the system crashes for example during kernel debugging (e.g., you 45 will be able to flush the buffer cache to disk, reboot the system 46 immediately or dump some status information). This is accomplished 47 by pressing various keys while holding SysRq (Alt+PrintScreen). It 48 also works on a serial console (on PC hardware at least), if you 49 send a BREAK and then within 5 seconds a command keypress. The 50 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y 51 unless you really know what this hack does. 52 53config UNUSED_SYMBOLS 54 bool "Enable unused/obsolete exported symbols" 55 default y if X86 56 help 57 Unused but exported symbols make the kernel needlessly bigger. For 58 that reason most of these unused exports will soon be removed. This 59 option is provided temporarily to provide a transition period in case 60 some external kernel module needs one of these symbols anyway. If you 61 encounter such a case in your module, consider if you are actually 62 using the right API. (rationale: since nobody in the kernel is using 63 this in a module, there is a pretty good chance it's actually the 64 wrong interface to use). If you really need the symbol, please send a 65 mail to the linux kernel mailing list mentioning the symbol and why 66 you really need it, and what the merge plan to the mainline kernel for 67 your module is. 68 69config DEBUG_FS 70 bool "Debug Filesystem" 71 depends on SYSFS 72 help 73 debugfs is a virtual file system that kernel developers use to put 74 debugging files into. Enable this option to be able to read and 75 write to these files. 76 77 For detailed documentation on the debugfs API, see 78 Documentation/DocBook/filesystems. 79 80 If unsure, say N. 81 82config HEADERS_CHECK 83 bool "Run 'make headers_check' when building vmlinux" 84 depends on !UML 85 help 86 This option will extract the user-visible kernel headers whenever 87 building the kernel, and will run basic sanity checks on them to 88 ensure that exported files do not attempt to include files which 89 were not exported, etc. 90 91 If you're making modifications to header files which are 92 relevant for userspace, say 'Y', and check the headers 93 exported to $(INSTALL_HDR_PATH) (usually 'usr/include' in 94 your build tree), to make sure they're suitable. 95 96config DEBUG_SECTION_MISMATCH 97 bool "Enable full Section mismatch analysis" 98 depends on UNDEFINED 99 # This option is on purpose disabled for now. 100 # It will be enabled when we are down to a resonable number 101 # of section mismatch warnings (< 10 for an allyesconfig build) 102 help 103 The section mismatch analysis checks if there are illegal 104 references from one section to another section. 105 Linux will during link or during runtime drop some sections 106 and any use of code/data previously in these sections will 107 most likely result in an oops. 108 In the code functions and variables are annotated with 109 __init, __devinit etc. (see full list in include/linux/init.h) 110 which results in the code/data being placed in specific sections. 111 The section mismatch analysis is always done after a full 112 kernel build but enabling this option will in addition 113 do the following: 114 - Add the option -fno-inline-functions-called-once to gcc 115 When inlining a function annotated __init in a non-init 116 function we would lose the section information and thus 117 the analysis would not catch the illegal reference. 118 This option tells gcc to inline less but will also 119 result in a larger kernel. 120 - Run the section mismatch analysis for each module/built-in.o 121 When we run the section mismatch analysis on vmlinux.o we 122 lose valueble information about where the mismatch was 123 introduced. 124 Running the analysis for each module/built-in.o file 125 will tell where the mismatch happens much closer to the 126 source. The drawback is that we will report the same 127 mismatch at least twice. 128 - Enable verbose reporting from modpost to help solving 129 the section mismatches reported. 130 131config DEBUG_KERNEL 132 bool "Kernel debugging" 133 help 134 Say Y here if you are developing drivers or trying to debug and 135 identify kernel problems. 136 137config DEBUG_SHIRQ 138 bool "Debug shared IRQ handlers" 139 depends on DEBUG_KERNEL && GENERIC_HARDIRQS 140 help 141 Enable this to generate a spurious interrupt as soon as a shared 142 interrupt handler is registered, and just before one is deregistered. 143 Drivers ought to be able to handle interrupts coming in at those 144 points; some don't and need to be caught. 145 146config DETECT_SOFTLOCKUP 147 bool "Detect Soft Lockups" 148 depends on DEBUG_KERNEL && !S390 149 default y 150 help 151 Say Y here to enable the kernel to detect "soft lockups", 152 which are bugs that cause the kernel to loop in kernel 153 mode for more than 60 seconds, without giving other tasks a 154 chance to run. 155 156 When a soft-lockup is detected, the kernel will print the 157 current stack trace (which you should report), but the 158 system will stay locked up. This feature has negligible 159 overhead. 160 161 (Note that "hard lockups" are separate type of bugs that 162 can be detected via the NMI-watchdog, on platforms that 163 support it.) 164 165config BOOTPARAM_SOFTLOCKUP_PANIC 166 bool "Panic (Reboot) On Soft Lockups" 167 depends on DETECT_SOFTLOCKUP 168 help 169 Say Y here to enable the kernel to panic on "soft lockups", 170 which are bugs that cause the kernel to loop in kernel 171 mode for more than 60 seconds, without giving other tasks a 172 chance to run. 173 174 The panic can be used in combination with panic_timeout, 175 to cause the system to reboot automatically after a 176 lockup has been detected. This feature is useful for 177 high-availability systems that have uptime guarantees and 178 where a lockup must be resolved ASAP. 179 180 Say N if unsure. 181 182config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE 183 int 184 depends on DETECT_SOFTLOCKUP 185 range 0 1 186 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC 187 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC 188 189config SCHED_DEBUG 190 bool "Collect scheduler debugging info" 191 depends on DEBUG_KERNEL && PROC_FS 192 default y 193 help 194 If you say Y here, the /proc/sched_debug file will be provided 195 that can help debug the scheduler. The runtime overhead of this 196 option is minimal. 197 198config SCHEDSTATS 199 bool "Collect scheduler statistics" 200 depends on DEBUG_KERNEL && PROC_FS 201 help 202 If you say Y here, additional code will be inserted into the 203 scheduler and related routines to collect statistics about 204 scheduler behavior and provide them in /proc/schedstat. These 205 stats may be useful for both tuning and debugging the scheduler 206 If you aren't debugging the scheduler or trying to tune a specific 207 application, you can say N to avoid the very slight overhead 208 this adds. 209 210config TIMER_STATS 211 bool "Collect kernel timers statistics" 212 depends on DEBUG_KERNEL && PROC_FS 213 help 214 If you say Y here, additional code will be inserted into the 215 timer routines to collect statistics about kernel timers being 216 reprogrammed. The statistics can be read from /proc/timer_stats. 217 The statistics collection is started by writing 1 to /proc/timer_stats, 218 writing 0 stops it. This feature is useful to collect information 219 about timer usage patterns in kernel and userspace. This feature 220 is lightweight if enabled in the kernel config but not activated 221 (it defaults to deactivated on bootup and will only be activated 222 if some application like powertop activates it explicitly). 223 224config DEBUG_OBJECTS 225 bool "Debug object operations" 226 depends on DEBUG_KERNEL 227 help 228 If you say Y here, additional code will be inserted into the 229 kernel to track the life time of various objects and validate 230 the operations on those objects. 231 232config DEBUG_OBJECTS_SELFTEST 233 bool "Debug objects selftest" 234 depends on DEBUG_OBJECTS 235 help 236 This enables the selftest of the object debug code. 237 238config DEBUG_OBJECTS_FREE 239 bool "Debug objects in freed memory" 240 depends on DEBUG_OBJECTS 241 help 242 This enables checks whether a k/v free operation frees an area 243 which contains an object which has not been deactivated 244 properly. This can make kmalloc/kfree-intensive workloads 245 much slower. 246 247config DEBUG_OBJECTS_TIMERS 248 bool "Debug timer objects" 249 depends on DEBUG_OBJECTS 250 help 251 If you say Y here, additional code will be inserted into the 252 timer routines to track the life time of timer objects and 253 validate the timer operations. 254 255config DEBUG_SLAB 256 bool "Debug slab memory allocations" 257 depends on DEBUG_KERNEL && SLAB 258 help 259 Say Y here to have the kernel do limited verification on memory 260 allocation as well as poisoning memory on free to catch use of freed 261 memory. This can make kmalloc/kfree-intensive workloads much slower. 262 263config DEBUG_SLAB_LEAK 264 bool "Memory leak debugging" 265 depends on DEBUG_SLAB 266 267config SLUB_DEBUG_ON 268 bool "SLUB debugging on by default" 269 depends on SLUB && SLUB_DEBUG 270 default n 271 help 272 Boot with debugging on by default. SLUB boots by default with 273 the runtime debug capabilities switched off. Enabling this is 274 equivalent to specifying the "slub_debug" parameter on boot. 275 There is no support for more fine grained debug control like 276 possible with slub_debug=xxx. SLUB debugging may be switched 277 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying 278 "slub_debug=-". 279 280config SLUB_STATS 281 default n 282 bool "Enable SLUB performance statistics" 283 depends on SLUB && SLUB_DEBUG && SYSFS 284 help 285 SLUB statistics are useful to debug SLUBs allocation behavior in 286 order find ways to optimize the allocator. This should never be 287 enabled for production use since keeping statistics slows down 288 the allocator by a few percentage points. The slabinfo command 289 supports the determination of the most active slabs to figure 290 out which slabs are relevant to a particular load. 291 Try running: slabinfo -DA 292 293config DEBUG_PREEMPT 294 bool "Debug preemptible kernel" 295 depends on DEBUG_KERNEL && PREEMPT && (TRACE_IRQFLAGS_SUPPORT || PPC64) 296 default y 297 help 298 If you say Y here then the kernel will use a debug variant of the 299 commonly used smp_processor_id() function and will print warnings 300 if kernel code uses it in a preemption-unsafe way. Also, the kernel 301 will detect preemption count underflows. 302 303config DEBUG_RT_MUTEXES 304 bool "RT Mutex debugging, deadlock detection" 305 depends on DEBUG_KERNEL && RT_MUTEXES 306 help 307 This allows rt mutex semantics violations and rt mutex related 308 deadlocks (lockups) to be detected and reported automatically. 309 310config DEBUG_PI_LIST 311 bool 312 default y 313 depends on DEBUG_RT_MUTEXES 314 315config RT_MUTEX_TESTER 316 bool "Built-in scriptable tester for rt-mutexes" 317 depends on DEBUG_KERNEL && RT_MUTEXES 318 help 319 This option enables a rt-mutex tester. 320 321config DEBUG_SPINLOCK 322 bool "Spinlock and rw-lock debugging: basic checks" 323 depends on DEBUG_KERNEL 324 help 325 Say Y here and build SMP to catch missing spinlock initialization 326 and certain other kinds of spinlock errors commonly made. This is 327 best used in conjunction with the NMI watchdog so that spinlock 328 deadlocks are also debuggable. 329 330config DEBUG_MUTEXES 331 bool "Mutex debugging: basic checks" 332 depends on DEBUG_KERNEL 333 help 334 This feature allows mutex semantics violations to be detected and 335 reported. 336 337config DEBUG_LOCK_ALLOC 338 bool "Lock debugging: detect incorrect freeing of live locks" 339 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT 340 select DEBUG_SPINLOCK 341 select DEBUG_MUTEXES 342 select LOCKDEP 343 help 344 This feature will check whether any held lock (spinlock, rwlock, 345 mutex or rwsem) is incorrectly freed by the kernel, via any of the 346 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(), 347 vfree(), etc.), whether a live lock is incorrectly reinitialized via 348 spin_lock_init()/mutex_init()/etc., or whether there is any lock 349 held during task exit. 350 351config PROVE_LOCKING 352 bool "Lock debugging: prove locking correctness" 353 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT 354 select LOCKDEP 355 select DEBUG_SPINLOCK 356 select DEBUG_MUTEXES 357 select DEBUG_LOCK_ALLOC 358 default n 359 help 360 This feature enables the kernel to prove that all locking 361 that occurs in the kernel runtime is mathematically 362 correct: that under no circumstance could an arbitrary (and 363 not yet triggered) combination of observed locking 364 sequences (on an arbitrary number of CPUs, running an 365 arbitrary number of tasks and interrupt contexts) cause a 366 deadlock. 367 368 In short, this feature enables the kernel to report locking 369 related deadlocks before they actually occur. 370 371 The proof does not depend on how hard and complex a 372 deadlock scenario would be to trigger: how many 373 participant CPUs, tasks and irq-contexts would be needed 374 for it to trigger. The proof also does not depend on 375 timing: if a race and a resulting deadlock is possible 376 theoretically (no matter how unlikely the race scenario 377 is), it will be proven so and will immediately be 378 reported by the kernel (once the event is observed that 379 makes the deadlock theoretically possible). 380 381 If a deadlock is impossible (i.e. the locking rules, as 382 observed by the kernel, are mathematically correct), the 383 kernel reports nothing. 384 385 NOTE: this feature can also be enabled for rwlocks, mutexes 386 and rwsems - in which case all dependencies between these 387 different locking variants are observed and mapped too, and 388 the proof of observed correctness is also maintained for an 389 arbitrary combination of these separate locking variants. 390 391 For more details, see Documentation/lockdep-design.txt. 392 393config LOCKDEP 394 bool 395 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT 396 select STACKTRACE 397 select FRAME_POINTER if !X86 && !MIPS 398 select KALLSYMS 399 select KALLSYMS_ALL 400 401config LOCK_STAT 402 bool "Lock usage statistics" 403 depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT 404 select LOCKDEP 405 select DEBUG_SPINLOCK 406 select DEBUG_MUTEXES 407 select DEBUG_LOCK_ALLOC 408 default n 409 help 410 This feature enables tracking lock contention points 411 412 For more details, see Documentation/lockstat.txt 413 414config DEBUG_LOCKDEP 415 bool "Lock dependency engine debugging" 416 depends on DEBUG_KERNEL && LOCKDEP 417 help 418 If you say Y here, the lock dependency engine will do 419 additional runtime checks to debug itself, at the price 420 of more runtime overhead. 421 422config TRACE_IRQFLAGS 423 depends on DEBUG_KERNEL 424 bool 425 default y 426 depends on TRACE_IRQFLAGS_SUPPORT 427 depends on PROVE_LOCKING 428 429config DEBUG_SPINLOCK_SLEEP 430 bool "Spinlock debugging: sleep-inside-spinlock checking" 431 depends on DEBUG_KERNEL 432 help 433 If you say Y here, various routines which may sleep will become very 434 noisy if they are called with a spinlock held. 435 436config DEBUG_LOCKING_API_SELFTESTS 437 bool "Locking API boot-time self-tests" 438 depends on DEBUG_KERNEL 439 help 440 Say Y here if you want the kernel to run a short self-test during 441 bootup. The self-test checks whether common types of locking bugs 442 are detected by debugging mechanisms or not. (if you disable 443 lock debugging then those bugs wont be detected of course.) 444 The following locking APIs are covered: spinlocks, rwlocks, 445 mutexes and rwsems. 446 447config STACKTRACE 448 bool 449 depends on STACKTRACE_SUPPORT 450 451config DEBUG_KOBJECT 452 bool "kobject debugging" 453 depends on DEBUG_KERNEL 454 help 455 If you say Y here, some extra kobject debugging messages will be sent 456 to the syslog. 457 458config DEBUG_HIGHMEM 459 bool "Highmem debugging" 460 depends on DEBUG_KERNEL && HIGHMEM 461 help 462 This options enables addition error checking for high memory systems. 463 Disable for production systems. 464 465config DEBUG_BUGVERBOSE 466 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EMBEDDED 467 depends on BUG 468 depends on ARM || AVR32 || M32R || M68K || SPARC32 || SPARC64 || \ 469 FRV || SUPERH || GENERIC_BUG || BLACKFIN || MN10300 470 default !EMBEDDED 471 help 472 Say Y here to make BUG() panics output the file name and line number 473 of the BUG call as well as the EIP and oops trace. This aids 474 debugging but costs about 70-100K of memory. 475 476config DEBUG_INFO 477 bool "Compile the kernel with debug info" 478 depends on DEBUG_KERNEL 479 help 480 If you say Y here the resulting kernel image will include 481 debugging info resulting in a larger kernel image. 482 This adds debug symbols to the kernel and modules (gcc -g), and 483 is needed if you intend to use kernel crashdump or binary object 484 tools like crash, kgdb, LKCD, gdb, etc on the kernel. 485 Say Y here only if you plan to debug the kernel. 486 487 If unsure, say N. 488 489config DEBUG_VM 490 bool "Debug VM" 491 depends on DEBUG_KERNEL 492 help 493 Enable this to turn on extended checks in the virtual-memory system 494 that may impact performance. 495 496 If unsure, say N. 497 498config DEBUG_WRITECOUNT 499 bool "Debug filesystem writers count" 500 depends on DEBUG_KERNEL 501 help 502 Enable this to catch wrong use of the writers count in struct 503 vfsmount. This will increase the size of each file struct by 504 32 bits. 505 506 If unsure, say N. 507 508config DEBUG_MEMORY_INIT 509 bool "Debug memory initialisation" if EMBEDDED 510 default !EMBEDDED 511 help 512 Enable this for additional checks during memory initialisation. 513 The sanity checks verify aspects of the VM such as the memory model 514 and other information provided by the architecture. Verbose 515 information will be printed at KERN_DEBUG loglevel depending 516 on the mminit_loglevel= command-line option. 517 518 If unsure, say Y 519 520config DEBUG_LIST 521 bool "Debug linked list manipulation" 522 depends on DEBUG_KERNEL 523 help 524 Enable this to turn on extended checks in the linked-list 525 walking routines. 526 527 If unsure, say N. 528 529config DEBUG_SG 530 bool "Debug SG table operations" 531 depends on DEBUG_KERNEL 532 help 533 Enable this to turn on checks on scatter-gather tables. This can 534 help find problems with drivers that do not properly initialize 535 their sg tables. 536 537 If unsure, say N. 538 539config FRAME_POINTER 540 bool "Compile the kernel with frame pointers" 541 depends on DEBUG_KERNEL && \ 542 (X86 || CRIS || M68K || M68KNOMMU || FRV || UML || S390 || \ 543 AVR32 || SUPERH || BLACKFIN || MN10300) 544 default y if DEBUG_INFO && UML 545 help 546 If you say Y here the resulting kernel image will be slightly larger 547 and slower, but it might give very useful debugging information on 548 some architectures or if you use external debuggers. 549 If you don't debug the kernel, you can say N. 550 551config BOOT_PRINTK_DELAY 552 bool "Delay each boot printk message by N milliseconds" 553 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY 554 help 555 This build option allows you to read kernel boot messages 556 by inserting a short delay after each one. The delay is 557 specified in milliseconds on the kernel command line, 558 using "boot_delay=N". 559 560 It is likely that you would also need to use "lpj=M" to preset 561 the "loops per jiffie" value. 562 See a previous boot log for the "lpj" value to use for your 563 system, and then set "lpj=M" before setting "boot_delay=N". 564 NOTE: Using this option may adversely affect SMP systems. 565 I.e., processors other than the first one may not boot up. 566 BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect 567 what it believes to be lockup conditions. 568 569config RCU_TORTURE_TEST 570 tristate "torture tests for RCU" 571 depends on DEBUG_KERNEL 572 default n 573 help 574 This option provides a kernel module that runs torture tests 575 on the RCU infrastructure. The kernel module may be built 576 after the fact on the running kernel to be tested, if desired. 577 578 Say Y here if you want RCU torture tests to be built into 579 the kernel. 580 Say M if you want the RCU torture tests to build as a module. 581 Say N if you are unsure. 582 583config RCU_TORTURE_TEST_RUNNABLE 584 bool "torture tests for RCU runnable by default" 585 depends on RCU_TORTURE_TEST = y 586 default n 587 help 588 This option provides a way to build the RCU torture tests 589 directly into the kernel without them starting up at boot 590 time. You can use /proc/sys/kernel/rcutorture_runnable 591 to manually override this setting. This /proc file is 592 available only when the RCU torture tests have been built 593 into the kernel. 594 595 Say Y here if you want the RCU torture tests to start during 596 boot (you probably don't). 597 Say N here if you want the RCU torture tests to start only 598 after being manually enabled via /proc. 599 600config KPROBES_SANITY_TEST 601 bool "Kprobes sanity tests" 602 depends on DEBUG_KERNEL 603 depends on KPROBES 604 default n 605 help 606 This option provides for testing basic kprobes functionality on 607 boot. A sample kprobe, jprobe and kretprobe are inserted and 608 verified for functionality. 609 610 Say N if you are unsure. 611 612config BACKTRACE_SELF_TEST 613 tristate "Self test for the backtrace code" 614 depends on DEBUG_KERNEL 615 default n 616 help 617 This option provides a kernel module that can be used to test 618 the kernel stack backtrace code. This option is not useful 619 for distributions or general kernels, but only for kernel 620 developers working on architecture code. 621 622 Note that if you want to also test saved backtraces, you will 623 have to enable STACKTRACE as well. 624 625 Say N if you are unsure. 626 627config LKDTM 628 tristate "Linux Kernel Dump Test Tool Module" 629 depends on DEBUG_KERNEL 630 depends on KPROBES 631 depends on BLOCK 632 default n 633 help 634 This module enables testing of the different dumping mechanisms by 635 inducing system failures at predefined crash points. 636 If you don't need it: say N 637 Choose M here to compile this code as a module. The module will be 638 called lkdtm. 639 640 Documentation on how to use the module can be found in 641 drivers/misc/lkdtm.c 642 643config FAULT_INJECTION 644 bool "Fault-injection framework" 645 depends on DEBUG_KERNEL 646 help 647 Provide fault-injection framework. 648 For more details, see Documentation/fault-injection/. 649 650config FAILSLAB 651 bool "Fault-injection capability for kmalloc" 652 depends on FAULT_INJECTION 653 help 654 Provide fault-injection capability for kmalloc. 655 656config FAIL_PAGE_ALLOC 657 bool "Fault-injection capabilitiy for alloc_pages()" 658 depends on FAULT_INJECTION 659 help 660 Provide fault-injection capability for alloc_pages(). 661 662config FAIL_MAKE_REQUEST 663 bool "Fault-injection capability for disk IO" 664 depends on FAULT_INJECTION 665 help 666 Provide fault-injection capability for disk IO. 667 668config FAULT_INJECTION_DEBUG_FS 669 bool "Debugfs entries for fault-injection capabilities" 670 depends on FAULT_INJECTION && SYSFS && DEBUG_FS 671 help 672 Enable configuration of fault-injection capabilities via debugfs. 673 674config FAULT_INJECTION_STACKTRACE_FILTER 675 bool "stacktrace filter for fault-injection capabilities" 676 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT 677 depends on !X86_64 678 select STACKTRACE 679 select FRAME_POINTER 680 help 681 Provide stacktrace filter for fault-injection capabilities 682 683config LATENCYTOP 684 bool "Latency measuring infrastructure" 685 select FRAME_POINTER if !MIPS 686 select KALLSYMS 687 select KALLSYMS_ALL 688 select STACKTRACE 689 select SCHEDSTATS 690 select SCHED_DEBUG 691 depends on HAVE_LATENCYTOP_SUPPORT 692 help 693 Enable this option if you want to use the LatencyTOP tool 694 to find out which userspace is blocking on what kernel operations. 695 696source kernel/trace/Kconfig 697 698config PROVIDE_OHCI1394_DMA_INIT 699 bool "Remote debugging over FireWire early on boot" 700 depends on PCI && X86 701 help 702 If you want to debug problems which hang or crash the kernel early 703 on boot and the crashing machine has a FireWire port, you can use 704 this feature to remotely access the memory of the crashed machine 705 over FireWire. This employs remote DMA as part of the OHCI1394 706 specification which is now the standard for FireWire controllers. 707 708 With remote DMA, you can monitor the printk buffer remotely using 709 firescope and access all memory below 4GB using fireproxy from gdb. 710 Even controlling a kernel debugger is possible using remote DMA. 711 712 Usage: 713 714 If ohci1394_dma=early is used as boot parameter, it will initialize 715 all OHCI1394 controllers which are found in the PCI config space. 716 717 As all changes to the FireWire bus such as enabling and disabling 718 devices cause a bus reset and thereby disable remote DMA for all 719 devices, be sure to have the cable plugged and FireWire enabled on 720 the debugging host before booting the debug target for debugging. 721 722 This code (~1k) is freed after boot. By then, the firewire stack 723 in charge of the OHCI-1394 controllers should be used instead. 724 725 See Documentation/debugging-via-ohci1394.txt for more information. 726 727config FIREWIRE_OHCI_REMOTE_DMA 728 bool "Remote debugging over FireWire with firewire-ohci" 729 depends on FIREWIRE_OHCI 730 help 731 This option lets you use the FireWire bus for remote debugging 732 with help of the firewire-ohci driver. It enables unfiltered 733 remote DMA in firewire-ohci. 734 See Documentation/debugging-via-ohci1394.txt for more information. 735 736 If unsure, say N. 737 738source "samples/Kconfig" 739 740source "lib/Kconfig.kgdb" 741