linux/arch/um/kernel/process.c, branch v3.0.82

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

2010-03-30T13:02:32Z

percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn

uml: convert to seq_file/proc_fops

2009-12-15T16:53:25Z

Convert code away from ->read_proc/->write_proc interfaces. Switch to proc_create()/proc_create_data() which make addition of proc entries reliable wrt NULL ->proc_fops, NULL ->data and so on. Problem with ->read_proc et al is described here commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba "Fix rmmod/read/write races in /proc entries" Signed-off-by: Alexey Dobriyan Cc: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Simplify copy_thread()

2009-04-03T02:04:51Z

First argument unused since 2.3.11. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexey Dobriyan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nohz: prevent tick stop outside of the idle loop

2008-07-18T16:10:28Z

Jack Ren and Eric Miao tracked down the following long standing problem in the NOHZ code: scheduler switch to idle task enable interrupts Window starts here ----> interrupt happens (does not set NEED_RESCHED) irq_exit() stops the tick ----> interrupt happens (does set NEED_RESCHED) return from schedule() cpu_idle(): preempt_disable(); Window ends here The interrupts can happen at any point inside the race window. The first interrupt stops the tick, the second one causes the scheduler to rerun and switch away from idle again and we end up with the tick disabled. The fact that it needs two interrupts where the first one does not set NEED_RESCHED and the second one does made the bug obscure and extremly hard to reproduce and analyse. Kudos to Jack and Eric. Solution: Limit the NOHZ functionality to the idle loop to make sure that we can not run into such a situation ever again. cpu_idle() { preempt_disable(); while(1) { tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we are in the idle loop while (!need_resched()) halt(); tick_nohz_restart_sched_tick(); <- disables NOHZ mode preempt_enable_no_resched(); schedule(); preempt_disable(); } } In hindsight we should have done this forever, but ... /me grabs a large brown paperbag. Debugged-by: Jack Ren , Debugged-by: eric miao Signed-off-by: Thomas Gleixner

proc: remove proc_root from drivers

2008-04-29T15:06:18Z

Remove proc_root export. Creation and removal works well if parent PDE is supplied as NULL -- it worked always that way. So, one useless export removed and consistency added, some drivers created PDEs with &proc_root as parent but removed them as NULL and so on. Signed-off-by: Alexey Dobriyan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sched: add declaration of sched_tail to sched.h

2008-02-25T15:34:17Z

Avoids sparse warnings: kernel/sched.c:2170:17: warning: symbol 'schedule_tail' was not declared. Should it be static? Avoids the need for an external declaration in arch/um/process.c Signed-off-by: Harvey Harrison Signed-off-by: Ingo Molnar

aout: suppress A.OUT library support if !CONFIG_ARCH_SUPPORTS_AOUT

2008-02-08T17:22:30Z

Suppress A.OUT library support if CONFIG_ARCH_SUPPORTS_AOUT is not set. Not all architectures support the A.OUT binfmt, so the ELF binfmt should not be permitted to go looking for A.OUT libraries to load in such a case. Not only that, but under such conditions A.OUT core dumps are not produced either. To make this work, this patch also does the following: (1) Makes the existence of the contents of linux/a.out.h contingent on CONFIG_ARCH_SUPPORTS_AOUT. (2) Renames dump_thread() to aout_dump_thread() as it's only called by A.OUT core dumping code. (3) Moves aout_dump_thread() into asm/a.out-core.h and makes it inline. This is then included only where needed. This means that this bit of arch code will be stored in the appropriate A.OUT binfmt module rather than the core kernel. (4) Drops A.OUT support for Blackfin (according to Mike Frysinger it's not needed) and FRV. This patch depends on the previous patch to move STACK_TOP[_MAX] out of asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT format is available. [jdike@addtoit.com: uml: re-remove accidentally restored code] Signed-off-by: David Howells Cc: Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: style fixes in arch/um/kernel

2008-02-05T17:44:30Z

Joe Perches noticed some printks in smp.c that needed fixing. While I was in there, I did the usual tidying in arch/um/kernel, which should be fairly style-clean at this point: copyright updates emacs formatting comments removal include tidying style fixes Cc: Joe Perches Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: remove duplicate config symbol and unused file and variables

2008-02-05T17:44:29Z

Fix the repetition of the NET symbol. It was once in UML specific options and once in networking. I removed the first occurrence, as it makes more sense to me to keep it only in networking. It also removes a mostly empty file which is not used anymore and some unused variables. Signed-off-by: Karol Swietlicki Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

uml: use ptrace directly in libc code

2008-02-05T17:44:28Z

Some register accessor cleanups - userspace() was calling restore_registers and save_registers for no reason, since userspace() is on the libc side of the house, and these add no value over calling ptrace directly init_thread_registers and get_safe_registers were the same thing, so init_thread_registers is gone Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds