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path: root/fs/ioprio.c
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2008-01-28cfq-iosched: relax IOPRIO_CLASS_IDLE restrictionsJens Axboe
Currently you must be root to set idle io prio class on a process. This is due to the fact that the idle class is implemented as a true idle class, meaning that it will not make progress if someone else is requesting disk access. Unfortunately this means that it opens DOS opportunities by locking down file system resources, hence it is root only at the moment. This patch relaxes the idle class a little, by removing the truly idle part (which entals a grace period with associated timer). The modifications make the idle class as close to zero impact as can be done while still guarenteeing progress. This means we can relax the root only criteria as well. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28io context sharing: preliminary supportJens Axboe
Detach task state from ioc, instead keep track of how many processes are accessing the ioc. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-01-28ioprio: move io priority from task_struct to io_contextJens Axboe
This is where it belongs and then it doesn't take up space for a process that doesn't do IO. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-11-07ioprio: allow sys_ioprio_set() value of 0 to reset ioprio settingJens Axboe
Normally io priorities follow the CPU nice, unless a specific scheduling class has been set. Once that is set, there's no way to reset the behaviour to 'none' so that it follows CPU nice again. Currently passing in 0 as the ioprio class/value will return -1/EINVAL, change that to allow resetting of a set scheduling class. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2007-10-19Uninline find_task_by_xxx set of functionsPavel Emelyanov
The find_task_by_something is a set of macros are used to find task by pid depending on what kind of pid is proposed - global or virtual one. All of them are wrappers above the most generic one - find_task_by_pid_type_ns() - and just substitute some args for it. It turned out, that dereferencing the current->nsproxy->pid_ns construction and pushing one more argument on the stack inline cause kernel text size to grow. This patch moves all this stuff out-of-line into kernel/pid.c. Together with the next patch it saves a bit less than 400 bytes from the .text section. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19pid namespaces: changes to show virtual ids to userPavel Emelyanov
This is the largest patch in the set. Make all (I hope) the places where the pid is shown to or get from user operate on the virtual pids. The idea is: - all in-kernel data structures must store either struct pid itself or the pid's global nr, obtained with pid_nr() call; - when seeking the task from kernel code with the stored id one should use find_task_by_pid() call that works with global pids; - when showing pid's numerical value to the user the virtual one should be used, but however when one shows task's pid outside this task's namespace the global one is to be used; - when getting the pid from userspace one need to consider this as the virtual one and use appropriate task/pid-searching functions. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: nuther build fix] [akpm@linux-foundation.org: yet nuther build fix] [akpm@linux-foundation.org: remove unneeded casts] Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org> Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Paul Menage <menage@google.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12[PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_taskEric W. Biederman
There isn't any real advantage to this change except that it allows the old functions to be removed. Which is easier on maintenance and puts the code in a more uniform style. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-10-12[PATCH] block layer: ioprio_best function fixVasily Tarasov
Currently ioprio_best function first checks wethere aioprio or bioprio equals IOPRIO_CLASS_NONE (ioprio_valid() macros does that) and if it is so it returns bioprio/aioprio appropriately. Thus the next four lines, that set aclass/bclass to IOPRIO_CLASS_BE, if aclass/bclass == IOPRIO_CLASS_NONE, are never executed. The second problem: if aioprio from class IOPRIO_CLASS_NONE and bioprio from class IOPRIO_CLASS_IDLE are passed to ioprio_best function, it will return IOPRIO_CLASS_IDLE. It means that during __make_request we can merge two requests and set the priority of merged request to IDLE, while one of the initial requests originates from a process with NONE (default) priority. So we can get a situation when a process with default ioprio will experience IO starvation, while there is no process from real-time class in the system. Just removing ioprio_valid check should correct situation. Signed-off-by: Vasily Tarasov <vtaras@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2006-09-30[PATCH] Update axboe@suse.de email addressJens Axboe
As people often look for the copyright in files to see who to mail, update the link to a neutral one. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] Don't need to disable interrupts for tasklist_lockOleg Nesterov
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30[PATCH] cfq-iosched: kill cfq_exit_lockJens Axboe
cfq_exit_lock is protecting two things now: - The per-ioc rbtree of cfq_io_contexts - The per-cfqd linked list of cfq_io_contexts The per-cfqd linked list can be protected by the queue lock, as it is (by definition) per cfqd as the queue lock is. The per-ioc rbtree is mainly used and updated by the process itself only. The only outside use is the io priority changing. If we move the priority changing to not browsing the rbtree, we can remove any locking from the rbtree updates and lookup completely. Let the sys_ioprio syscall just mark processes as having the iopriority changed and lazily update the private cfq io contexts the next time io is queued, and we can remove this locking as well. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] uninline ioprio_best()Oleg Nesterov
Saves 376 bytes (5 callers) for me. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] Fix current_io_context() vs set_task_ioprio() raceOleg Nesterov
I know nothing about io scheduler, but I suspect set_task_ioprio() is not safe. current_io_context() initializes "struct io_context", then sets ->io_context. set_task_ioprio() running on another cpu may see the changes out of order, so ->set_ioprio(ioc) may use io_context which was not initialized properly. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-08-21[PATCH] sys_ioprio_set: minor do_each_thread+break fixOleg Nesterov
From include/linux/sched.h: * Careful: do_each_thread/while_each_thread is a double loop so * 'break' will not work as expected - use goto instead. */ Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Jens Axboe <axboe@suse.de>
2006-06-30[PATCH] SELinux: Add security hook definition for getioprio and insert hooksDavid Quigley
Add a new security hook definition for the sys_ioprio_get operation. At present, the SELinux hook function implementation for this hook is identical to the getscheduler implementation but a separate hook is introduced to allow this check to be specialized in the future if necessary. This patch also creates a helper function get_task_ioprio which handles the access check in addition to retrieving the ioprio value for the task. Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org> Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] lsm: add task_setioprio hookJames Morris
Implement an LSM hook for setting a task's IO priority, similar to the hook for setting a tasks's nice value. A previous version of this LSM hook was included in an older version of multiadm by Jan Engelhardt, although I don't recall it being submitted upstream. Also included is the corresponding SELinux hook, which re-uses the setsched permission in the proccess class. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Cc: Jan Engelhardt <jengelh@linux01.gwdg.de> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-11[PATCH] capable/capability.h (fs/)Randy Dunlap
fs: Use <linux/capability.h> where capable() is used. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Tim Schmielau <tim@physik3.uni-rostock.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-08fs/ioprio.c should #include <linux/syscalls.h>Adrian Bunk
Every file should include the headers containing the prototypes for it's global functions. Signed-off-by: Adrian Bunk <bunk@stusta.de>
2005-08-20Don't allow normal users to set idle IO priorityLinus Torvalds
It has all the normal priority inversion problems. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] move ioprio syscalls into syscalls.hAnton Blanchard
- Make ioprio syscalls return long, like set/getpriority syscalls. - Move function prototypes into syscalls.h so we can pick them up in the 32/64bit compat code. Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Jens Axboe <axboe@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27[PATCH] Update cfq io scheduler to time sliced designJens Axboe
This updates the CFQ io scheduler to the new time sliced design (cfq v3). It provides full process fairness, while giving excellent aggregate system throughput even for many competing processes. It supports io priorities, either inherited from the cpu nice value or set directly with the ioprio_get/set syscalls. The latter closely mimic set/getpriority. This import is based on my latest from -mm. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>