- Sep 11, 2005
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Ingo Molnar authored
This patch implements a task state bit (TASK_NONINTERACTIVE), which can be used by blocking points to mark the task's wait as "non-interactive". This does not mean the task will be considered a CPU-hog - the wait will simply not have an effect on the waiting task's priority - positive or negative alike. Right now only pipe_wait() will make use of it, because it's a common source of not-so-interactive waits (kernel compilation jobs, etc.). Signed-off-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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Ingo Molnar authored
whitespace cleanups. Signed-off-by:
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M.Baris Demiray authored
Add relevant checks into find_idlest_group() and find_idlest_cpu() to make them return only the groups that have allowed CPUs and allowed CPUs respectively. Signed-off-by:
M.Baris Demiray <baris@labristeknoloji.com> Signed-off-by:
Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:
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Con Kolivas authored
The hyperthread aware nice handling currently puts to sleep any non real time task when a real time task is running on its sibling cpu. This can lead to prolonged starvation by having the non real time task pegged to the cpu with load balancing not pulling that task away. Currently we force lower priority hyperthread tasks to run a percentage of time difference based on timeslice differences which is meaningless when comparing real time tasks to SCHED_NORMAL tasks. We can allow non real time tasks to run with real time tasks on the sibling up to per_cpu_gain% if we use jiffies as a counter. Cleanups and micro-optimisations to the relevant code section should make it more understandable as well. Signed-off-by:
Con Kolivas <kernel@kolivas.org> Acked-by:
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Paul Fulghum authored
Add ability to clear statistics. Signed-off-by:
Paul Fulghum <paulkf@microgate.com> Signed-off-by:
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Paul Jackson authored
The cpusets-formalize-intermediate-gfp_kernel-containment patch has a deadlock problem. This patch was part of a set of four patches to make more extensive use of the cpuset 'mem_exclusive' attribute to manage kernel GFP_KERNEL memory allocations and to constrain the out-of-memory (oom) killer. A task that is changing cpusets in particular ways on a system when it is very short of free memory could double trip over the global cpuset_sem semaphore (get the lock and then deadlock trying to get it again). The second attempt to get cpuset_sem would be in the routine cpuset_zone_allowed(). This was discovered by code inspection. I can not reproduce the problem except with an artifically hacked kernel and a specialized stress test. In real life you cannot hit this unless you are manipulating cpusets, and are very unlikely to hit it unless you are rapidly modifying cpusets on a memory tight system. Even then it would be a rare occurence. If you did hit it, the task double tripping over cpuset_sem would deadlock in the kernel, and any other task also trying to manipulate cpusets would deadlock there too, on cpuset_sem. Your batch manager would be wedged solid (if it was cpuset savvy), but classic Unix shells and utilities would work well enough to reboot the system. The unusual condition that led to this bug is that unlike most semaphores, cpuset_sem _can_ be acquired while in the page allocation code, when __alloc_pages() calls cpuset_zone_allowed. So it easy to mistakenly perform the following sequence: 1) task makes system call to alter a cpuset 2) take cpuset_sem 3) try to allocate memory 4) memory allocator, via cpuset_zone_allowed, trys to take cpuset_sem 5) deadlock The reason that this is not a serious bug for most users is that almost all calls to allocate memory don't require taking cpuset_sem. Only some code paths off the beaten track require taking cpuset_sem -- which is good. Taking a global semaphore on the main code path for allocating memory would not scale well. This patch fixes this deadlock by wrapping the up() and down() calls on cpuset_sem in kernel/cpuset.c with code that tracks the nesting depth of the current task on that semaphore, and only does the real down() if the task doesn't hold the lock already, and only does the real up() if the nesting depth (number of unmatched downs) is exactly one. The previous required use of refresh_mems(), anytime that the cpuset_sem semaphore was acquired and the code executed while holding that semaphore might try to allocate memory, is no longer required. Two refresh_mems() calls were removed thanks to this. This is a good change, as failing to get all the necessary refresh_mems() calls placed was a primary source of bugs in this cpuset code. The only remaining call to refresh_mems() is made while doing a memory allocation, if certain task memory placement data needs to be updated from its cpuset, due to the cpuset having been changed behind the tasks back. Signed-off-by:
Paul Jackson <pj@sgi.com> Signed-off-by:
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Ingo Molnar authored
This patch (written by me and also containing many suggestions of Arjan van de Ven) does a major cleanup of the spinlock code. It does the following things: - consolidates and enhances the spinlock/rwlock debugging code - simplifies the asm/spinlock.h files - encapsulates the raw spinlock type and moves generic spinlock features (such as ->break_lock) into the generic code. - cleans up the spinlock code hierarchy to get rid of the spaghetti. Most notably there's now only a single variant of the debugging code, located in lib/spinlock_debug.c. (previously we had one SMP debugging variant per architecture, plus a separate generic one for UP builds) Also, i've enhanced the rwlock debugging facility, it will now track write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too. All locks have lockup detection now, which will work for both soft and hard spin/rwlock lockups. The arch-level include files now only contain the minimally necessary subset ...
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Alan Cox authored
pcibus_to_cpumask expands into more than just an initialiser so gcc moans about code before variable declarations. Signed-off-by:
Alan Cox <alan@redhat.com> Signed-off-by:
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Andrew Morton authored
*** Warning: "bit_spin_lock" [fs/ntfs/ntfs.ko] undefined! *** Warning: "bit_spin_unlock" [fs/ntfs/ntfs.ko] undefined! Cc: Anton Altaparmakov <aia21@cantab.net> Signed-off-by:
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- Sep 10, 2005
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NeilBrown authored
This shouldn't be a BUG. We should cope. Signed-off-by:
Neil Brown <neilb@suse.de> Signed-off-by:
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NeilBrown authored
If you try to assemble an array with too many missing devices, raid10 will now reject the attempt, instead of allowing it. Also check when hot-adding a drive and refuse the hot-add if the array is beyond hope. Signed-off-by:
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NeilBrown authored
There was another case where sb_size wasn't being set, so instead do the sensible thing and set if when filling in the content of a superblock. That ensures that whenever we write a superblock, the sb_size MUST be set. Signed-off-by:
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NeilBrown authored
[PATCH] md: make sure the new 'sb_size' is set properly device added without pre-existing superblock. There are two ways to add devices to an md/raid array. It can have superblock written to it, and then given to the md driver, which will read the superblock (the new way) or md can be told (through SET_ARRAY_INFO) the shape of the array, and the told about individual drives, and md will create the required superblock (the old way). The newly introduced sb_size was only set for drives being added the new way, not the old ways. Oops :-( Signed-off-by:
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NeilBrown authored
Just like failed drives have (F), so spare drives now have (S). Signed-off-by:
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NeilBrown authored
Leave it unchanged if the original (0.90) is used, incase it might be a compatability problem. Signed-off-by:
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NeilBrown authored
Doh. I want the physical hard-sector-size, not the current block size... Signed-off-by:
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NeilBrown authored
On reflection, a better default location for hot-adding bitmaps with version-1 superblocks is immediately after the superblock. There might not be much room there, but there is usually atleast 3k, and that is a good start. Signed-off-by:
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NeilBrown authored
The bitmap code used to have two daemons, so there is some 'common' start/stop code. But now there is only one, so the common code is just noise. This patch tidies this up somewhat. Signed-off-by:
Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by:
Adrian Bunk <bunk@stusta.de> Signed-off-by:
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NeilBrown authored
mddev->bitmap gets clearred before the writeback daemon is stopped. So the write_back daemon needs to be careful not to dereference the 'bitmap' if it is NULL. Signed-off-by:
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NeilBrown authored
Switch MD to use the kthread infrastructure, to simplify the code and get rid of tasklist_lock abuse in md_unregister_thread. Also don't flush signals in md_thread, as the called thread will always do that. Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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NeilBrown authored
This is a direct port of the raid5 patch. Signed-off-by:
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NeilBrown authored
Most awkward part of this is delaying write requests until bitmap updates have been flushed. To achieve this, we have a sequence number (seq_flush) which is incremented each time the raid5 is unplugged. If the raid thread notices that this has changed, it flushes bitmap changes, and assigned the value of seq_flush to seq_write. When a write request arrives, it is given the number from seq_write, and that write request may not complete until seq_flush is larger than the saved seq number. We have a new queue for storing stripes which are waiting for a bitmap flush and an extra flag for stripes to record if the write was 'degraded' and so should not clear the a bit in the bitmap. Signed-off-by:
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NeilBrown authored
version-1 superblocks are not (normally) 4K long, and can be of variable size. Writing the full 4K can cause corruption (but only in non-default configurations). With this patch the super-block-flavour can choose a size to read, and set a size to write based on what it finds. Signed-off-by:
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NeilBrown authored
These inlines haven't been used for ages, they should go. Signed-off-by:
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NeilBrown authored
read_sb_page() assumed that if sync_page_io fails, the device would be marked faultly. However it isn't. So in the face of error, read_sb_page would loop forever. Redo the logic so that this cannot happen. Signed-off-by:
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NeilBrown authored
As this is used to flag an internal bitmap. Also, introduce symbolic names for feature bits. Signed-off-by:
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NeilBrown authored
It is possibly (and occasionally useful) to have a raid1 without persistent superblocks. The code in add_new_disk for adding a device to such an array always tries to read a superblock. This will obviously fail. So do the appropriate test and call md_import_device with appropriate args. Signed-off-by:
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NeilBrown authored
When hot-adding a bitmap, bitmap_daemon_work could get called while the bitmap is being created, so don't set mddev->bitmap until the bitmap is ready. This requires freeing the bitmap inside bitmap_create if creation failed part-way through. Signed-off-by:
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NeilBrown authored
The 'lastrun' time wasn't being initialised, so it could be half a jiffie-cycle before it seemed to be time to do work again. Signed-off-by:
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NeilBrown authored
A state of 0 mean 'not quiesced' A state of 1 means 'is quiesced' The original code got this wrong. Signed-off-by:
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NeilBrown authored
linear currently uses division by the size of the smallest componenet device to find which device a request goes to. If that smallest device is larger than 2 terabytes, then the division will not work on some systems. So we introduce a pre-shift, and take care not to make the hash table too large, much like the code in raid0. Also get rid of conf->nr_zones, which is not needed. Signed-off-by:
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NeilBrown authored
If a device is flagged 'WriteMostly' and the array has a bitmap, and the bitmap superblock indicates that write_behind is allowed, then write_behind is enabled for WriteMostly devices. Write requests will be acknowledges as complete to the caller (via b_end_io) when all non-WriteMostly devices have completed the write, but will not be cleared from the bitmap until all devices complete. This requires memory allocation to make a local copy of the data being written. If there is insufficient memory, then we fall-back on normal write semantics. Signed-Off-By:
Paul Clements <paul.clements@steeleye.com> Signed-off-by:
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NeilBrown authored
This allows a device in a raid1 to be marked as "write mostly". Read requests will only be sent if there is no other option. Signed-off-by:
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NeilBrown authored
Both file-bitmaps and superblock bitmaps are supported. If you add a bitmap file on the array device, you lose. This introduces a 'default_bitmap_offset' field in mddev, as the ioctl used for adding a superblock bitmap doesn't have room for giving an offset. Later, this value will be setable via sysfs. Signed-off-by:
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NeilBrown authored
When we find a 'stale' bitmap, possibly because it is new, we should just assume every bit needs to be set, but rather base the setting of bits on the current state of the array (degraded and recovery_cp). Signed-off-by:
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NeilBrown authored
... otherwise we loose a reference and can never free the file. Signed-off-by:
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Jun'ichi Nomura authored
Fix another bug in dm-raid1.c that the dirty region may stay in or be moved to clean list and freed while in use. It happens as follows: CPU0 CPU1 ------------------------------------------------------------------------------ rh_dec() if (atomic_dec_and_test(pending)) <the region is still marked dirty> rh_inc() if the region is clean mark the region dirty and remove from clean list mark the region clean and move to clean list atomic_inc(pending) At this stage, the region is in clean list and will be mistakenly reclaimed by rh_update_states() later. Signed-off-by:Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by:
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NeilBrown authored
md does not yet support BIO_RW_BARRIER, so be honest about it and fail (-EOPNOTSUPP) any such requests. Signed-off-by:
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NeilBrown authored
'this_sector' is a virtual (array) address while 'head_position' is a physical (device) address, so substraction doesn't make any sense. devs[slot].addr should be used instead of this_sector. However, this patch doesn't make much practical different to the read balancing due to the effects of later code. Signed-off-by:
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Linus Torvalds authored
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