- 23 Jun, 2005 40 commits
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Jesper Juhl authored
In kernel/sched.c the return value from preempt_count() is cast to an int. That made sense when preempt_count was defined as different types on is not needed and should go away. The patch removes the cast. In kernel/timer.c the return value from preempt_count() is assigned to a variable of type u32 and then that unsigned value is later compared to preempt_count(). Since preempt_count() returns an int, an int is what should be used to store its return value. Storing the result in an unsigned 32bit integer made a tiny bit of sense back when preempt_count was different types on different archs, but no more - let's not play signed vs unsigned comparison games when we don't have to. The patch modifies the code to use an int to hold the value. While I was around that bit of code I also made two changes to a nearby (related) printk() - I modified it to specify the loglevel explicitly and also broke the line into a few pieces to avoid it being longer than 80 chars and clarified the text a bit. Signed-off-by:
Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by:
Andrew Morton <akpm@osdl.org> Signed-off-by:
Linus Torvalds <torvalds@osdl.org>
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Jesper Juhl authored
The preempt_count member of struct thread_info is currently either defined as int, unsigned int or __s32 depending on arch. This patch makes the type of preempt_count an int on all archs. Having preempt_count be an unsigned type prevents the catching of preempt_count < 0 bugs, and using int on some archs and __s32 on others is not exactely "neat" - much nicer when it's just int all over. A previous version of this patch was already ACK'ed by Robert Love, and the only change in this version of the patch compared to the one he ACK'ed is that this one also makes sure the preempt_count member is consistently commented. Signed-off-by:
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Nick Piggin authored
Looks like locking can be optimised quite a lot. Increase lock widths slightly so lo_lock is taken fewer times per request. Also it was quite trivial to cover lo_pending with that lock, and remove the atomic requirement. This also makes memory ordering explicitly correct, which is nice (not that I particularly saw any mem ordering bugs). Test was reading 4 250MB files in parallel on ext2-on-tmpfs filesystem (1K block size, 4K page size). System is 2 socket Xeon with HT (4 thread). intel:/home/npiggin# umount /dev/loop0 ; mount /dev/loop0 /mnt/loop ; /usr/bin/time ./mtloop.sh Before: 0.24user 5.51system 0:02.84elapsed 202%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.52system 0:02.88elapsed 198%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.57system 0:02.89elapsed 198%CPU (0avgtext+0avgdata 0maxresident)k 0.22user 5.51system 0:02.90elapsed 197%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.44system 0:02.91elapsed 193%CPU (0avgtext+0avgdata 0maxresident)k After: 0.07user 2.34system 0:01.68elapsed 143%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.37system 0:01.68elapsed 144%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.39system 0:01.68elapsed 145%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.36system 0:01.68elapsed 144%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.42system 0:01.68elapsed 147%CPU (0avgtext+0avgdata 0maxresident)k Signed-off-by:
Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by:
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Greg Edwards authored
According to include/linux/console.h, CON_CONSDEV flag should be set on the last console specified on the boot command line: 86 #define CON_PRINTBUFFER (1) 87 #define CON_CONSDEV (2) /* Last on the command line */ 88 #define CON_ENABLED (4) 89 #define CON_BOOT (8) This does not currently happen if there is more than one console specified on the boot commandline. Instead, it gets set on the first console on the command line. This can cause problems for things like kdb that look for the CON_CONSDEV flag to see if the console is valid. Additionaly, it doesn't look like CON_CONSDEV is reassigned to the next preferred console at unregister time if the console being unregistered currently has that bit set. Example (from sn2 ia64): elilo vmlinuz root=<dev> console=ttyS0 console=ttySG0 in this case, the flags on ttySG console struct will be 0x4 (should be 0x6). Attached patch against bk fixes both issues for the cases I looked at. It uses selected_console (which gets incremented for each console specified on the command line) as the indicator of which console to set CON_CONSDEV on. When adding the console to the list, if the previous one had CON_CONSDEV set, it masks it out. Tested on ia64 and x86. The problem with the current behavior is it breaks overriding the default from the boot line. In the ia64 case, there may be a global append line defining console=a in elilo.conf. Then you want to boot your kernel, and want to override the default by passing console=b on the boot line. elilo constructs the kernel cmdline by starting with the value of the global append line, then tacks on whatever else you specify, which puts console=b last. Signed-off-by:Greg Edwards <edwardsg@sgi.com> Signed-off-by:
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Robert Love authored
Convert a bunch of strdup() implementations and their callers to the new kstrdup(). A few remain, for example see sound/core, and there are tons of open coded strdup()'s around. Sigh. But this is a start. Signed-off-by:
Robert Love <rml@novell.com> Signed-off-by:
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Paulo Marques authored
This patch creates a new kstrdup library function and changes the "local" implementations in several places to use this function. Most of the changes come from the sound and net subsystems. The sound part had already been acknowledged by Takashi Iwai and the net part by David S. Miller. I left UML alone for now because I would need more time to read the code carefully before making changes there. Signed-off-by:
Paulo Marques <pmarques@grupopie.com> Signed-off-by:
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Alexander Viro authored
Based on analysis and a patch from Russ Weight <rweight@us.ibm.com> There is a race condition that can occur if an inode is allocated and then released (using iput) during the ->fill_super functions. The race condition is between kswapd and mount. For most filesystems this can only happen in an error path when kswapd is running concurrently. For isofs, however, the error can occur in a more common code path (which is how the bug was found). The logic here is "we want final iput() to free inode *now* instead of letting it sit in cache if fs is going down or had not quite come up". The problem is with kswapd seeing such inodes in the middle of being killed and happily taking over. The clean solution would be to tell kswapd to leave those inodes alone and let our final iput deal with them. I.e. add a new flag (I_FORCED_FREEING), set it before write_inode_now() there and make prune_icache() leave those alone. Signed-off-by:
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Oleg Nesterov authored
sys_timer_settime/sys_timer_delete needs to delete k_itimer->real.timer synchronously while holding ->it_lock, which is also locked in posix_timer_fn. This patch removes timer_active/set_timer_inactive which plays with timer_list's internals in favour of using try_to_del_timer_sync(), which was introduced in the previous patch. Signed-off-by:
Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by:
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Oleg Nesterov authored
This patch splits del_timer_sync() into 2 functions. The new one, try_to_del_timer_sync(), returns -1 when it hits executing timer. It can be used in interrupt context, or when the caller hold locks which can prevent completion of the timer's handler. NOTE. Currently it can't be used in interrupt context in UP case, because ->running_timer is used only with CONFIG_SMP. Should the need arise, it is possible to kill #ifdef CONFIG_SMP in set_running_timer(), it is cheap. Signed-off-by:
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Oleg Nesterov authored
This patch tries to solve following problems: 1. del_timer_sync() is racy. The timer can be fired again after del_timer_sync have checked all cpus and before it will recheck timer_pending(). 2. It has scalability problems. All cpus are scanned to determine if the timer is running on that cpu. With this patch del_timer_sync is O(1) and no slower than plain del_timer(pending_timer), unless it has to actually wait for completion of the currently running timer. The only restriction is that the recurring timer should not use add_timer_on(). 3. The timers are not serialized wrt to itself. If CPU_0 does mod_timer(jiffies+1) while the timer is currently running on CPU 1, it is quite possible that local interrupt on CPU_0 will start that timer before it finished on CPU_1. 4. The timers locking is suboptimal. __mod_timer() takes 3 locks at once and still requires wmb() in del_timer/run_timers. The new implementation takes 2 locks sequentially and does not need memory barriers. Currently ->base != NULL means that the timer is pending. In that case ->base.lock is used to lock the timer. __mod_timer also takes timer->lock because ->base can be == NULL. This patch uses timer->entry.next != NULL as indication that the timer is pending. So it does __list_del(), entry->next = NULL instead of list_del() when the timer is deleted. The ->base field is used for hashed locking only, it is initialized in init_timer() which sets ->base = per_cpu(tvec_bases). When the tvec_bases.lock is locked, it means that all timers which are tied to this base via timer->base are locked, and the base itself is locked too. So __run_timers/migrate_timers can safely modify all timers which could be found on ->tvX lists (pending timers). When the timer's base is locked, and the timer removed from ->entry list (which means that _run_timers/migrate_timers can't see this timer), it is possible to set timer->base = NULL and drop the lock: the timer remains locked. This patch adds lock_timer_base() helper, which waits for ->base != NULL, locks the ->base, and checks it is still the same. __mod_timer() schedules the timer on the local CPU and changes it's base. However, it does not lock both old and new bases at once. It locks the timer via lock_timer_base(), deletes the timer, sets ->base = NULL, and unlocks old base. Then __mod_timer() locks new_base, sets ->base = new_base, and adds this timer. This simplifies the code, because AB-BA deadlock is not possible. __mod_timer() also ensures that the timer's base is not changed while the timer's handler is running on the old base. __run_timers(), del_timer() do not change ->base anymore, they only clear pending flag. So del_timer_sync() can test timer->base->running_timer == timer to detect whether it is running or not. We don't need timer_list->lock anymore, this patch kills it. We also don't need barriers. del_timer() and __run_timers() used smp_wmb() before clearing timer's pending flag. It was needed because __mod_timer() did not lock old_base if the timer is not pending, so __mod_timer()->list_add() could race with del_timer()->list_del(). With this patch these functions are serialized through base->lock. One problem. TIMER_INITIALIZER can't use per_cpu(tvec_bases). So this patch adds global struct timer_base_s { spinlock_t lock; struct timer_list *running_timer; } __init_timer_base; which is used by TIMER_INITIALIZER. The corresponding fields in tvec_t_base_s struct are replaced by struct timer_base_s t_base. It is indeed ugly. But this can't have scalability problems. The global __init_timer_base.lock is used only when __mod_timer() is called for the first time AND the timer was compile time initialized. After that the timer migrates to the local CPU. Signed-off-by:Ingo Molnar <mingo@elte.hu> Signed-off-by:
Renaud Lienhart <renaud.lienhart@free.fr> Signed-off-by:
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Nick Piggin authored
get_request_wait needn't unplug the device immediately. Signed-off-by:
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Nick Piggin authored
Sprinkle around a few branch hints in the block layer. Signed-off-by:
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Nick Piggin authored
This memory barrier is not needed because the waitqueue will only get waiters on it in the following situations: rq->count has exceeded the threshold - however all manipulations of ->count are performed under the runqueue lock, and so we will correctly pick up any waiter. Memory allocation for the request fails. In this case, there is no additional help provided by the memory barrier. We are guaranteed to eventually wake up waiters because the request allocation mempool guarantees that if the mem allocation for a request fails, there must be some requests in flight. They will wake up waiters when they are retired. Signed-off-by:
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Tejun Heo authored
Add KERN_ERR and __FUNCTION__ to generic tag error messages, and add a comment in blk_queue_end_tag() which explains the silent failure path. Signed-off-by:
Tejun Heo <htejun@gmail.com> Acked-by:
Jens Axboe <axboe@suse.de> Signed-off-by:
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Tejun Heo authored
Replace BLK_TAGS_PER_LONG with BITS_PER_LONG and remove unused BLK_TAGS_MASK. Signed-off-by:
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Tejun Heo authored
blk_queue_tag->real_max_depth was used to optimize out unnecessary allocations/frees on tag resize. However, the whole thing was very broken - tag_map was never allocated to real_max_depth resulting in access beyond the end of the map, bits in [max_depth..real_max_depth] were set when initializing a map and copied when resizing resulting in pre-occupied tags. As the gain of the optimization is very small, well, almost nill, remove the whole thing. Signed-off-by:
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Tejun Heo authored
blk_queue_start_tag() hand-coded searching for the first zero bit in the tag map. Replace it with find_first_zero_bit(). With this patch, blk_queue_star_tag() doesn't need to fill remains of tag map with 1, thus allowing it to work properly with the next remove_real_max_depth patch. Signed-off-by:
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Domen Puncer authored
Assignment doesn't make much sense here as condition would always be true. Signed-off-by:
Domen Puncer <domen@coderock.org> Signed-off-by:
Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Vincent Hanquez authored
Make use of the user_mode macro where it's possible. This is useful for Xen because it will need only to redefine only the macro to a hypervisor call. Signed-off-by:
Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk> Cc: Ian Pratt <m+Ian.Pratt@cl.cam.ac.uk> Cc: Andi Kleen <ak@muc.de> Signed-off-by:
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Vincent Hanquez authored
Add 2 macros to set and get debugreg on x86_64. This is useful for Xen because it will need only to redefine each macro to a hypervisor call. Signed-off-by:
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Vincent Hanquez authored
Use the user_mode macro where it's possible. Signed-off-by:
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Vincent Hanquez authored
Rename user_mode to user_mode_vm and add a user_mode macro similar to the x86-64 one. This is useful for Xen because the linux xen kernel does not runs on the same priviledge that a vanilla linux kernel, and with this we just need to redefine user_mode(). Signed-off-by:
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Vincent Hanquez authored
Make use of the 2 new macro set_debugreg and get_debugreg. Signed-off-by:
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Vincent Hanquez authored
Add 2 macros to set and get debugreg on x86. This is useful for Xen because it will need only to redefine each macro to a hypervisor call. Signed-off-by:
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Natalie Protasevich authored
I suggest to change the way IRQs are handed out to PCI devices. Currently, each I/O APIC pin gets associated with an IRQ, no matter if the pin is used or not. It is expected that each pin can potentually be engaged by a device inserted into the corresponding PCI slot. However, this imposes severe limitation on systems that have designs that employ many I/O APICs, only utilizing couple lines of each, such as P64H2 chipset. It is used in ES7000, and currently, there is no way to boot the system with more that 9 I/O APICs. The simple change below allows to boot a system with say 64 (or more) I/O APICs, each providing 1 slot, which otherwise impossible because of the IRQ gaps created for unused lines on each I/O APIC. It does not resolve the problem with number of devices that exceeds number of possible IRQs, but eases up a tension for IRQs on any large system with potentually large number of devices. I only implemented this for the ACPI boot, since if the system is this big and using newer chipsets it is probably (better be!) an ACPI based system :). The change is completely "mechanical" and does not alter any internal structures or interrupt model/implementation. The patch works for both i386 and x86_64 archs. It works with MSIs just fine, and should not intervene with implementations like shared vectors, when they get worked out and incorporated. To illustrate, below is the interrupt distribution for 2-cell ES7000 with 20 I/O APICs, and an Ethernet card in the last slot, which should be eth1 and which was not configured because its IRQ exceeded allowable number (it actially turned out huge - 480!): zorro-tb2:~ # cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 0: 65716 30012 30007 30002 30009 30010 30010 30010 IO-APIC-edge timer 4: 373 0 725 280 0 0 0 0 IO-APIC-edge serial 8: 0 0 0 0 0 0 0 0 IO-APIC-edge rtc 9: 0 0 0 0 0 0 0 0 IO-APIC-level acpi 14: 39 3 0 0 0 0 0 0 IO-APIC-edge ide0 16: 108 13 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb1 18: 0 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb3 19: 15 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb2 23: 3 0 0 0 0 0 0 0 IO-APIC-level ehci_hcd:usb4 96: 4240 397 18 0 0 0 0 0 IO-APIC-level aic7xxx 97: 15 0 0 0 0 0 0 0 IO-APIC-level aic7xxx 192: 847 0 0 0 0 0 0 0 IO-APIC-level eth0 NMI: 0 0 0 0 0 0 0 0 LOC: 273423 274528 272829 274228 274092 273761 273827 273694 ERR: 7 MIS: 0 Even though the system doesn't have that many devices, some don't get enabled only because of IRQ numbering model. This is the IRQ picture after the patch was applied: zorro-tb2:~ # cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 0: 44169 10004 10004 10001 10004 10003 10004 6135 IO-APIC-edge timer 4: 345 0 0 0 0 244 0 0 IO-APIC-edge serial 8: 0 0 0 0 0 0 0 0 IO-APIC-edge rtc 9: 0 0 0 0 0 0 0 0 IO-APIC-level acpi 14: 39 0 3 0 0 0 0 0 IO-APIC-edge ide0 17: 4425 0 9 0 0 0 0 0 IO-APIC-level aic7xxx 18: 15 0 0 0 0 0 0 0 IO-APIC-level aic7xxx, uhci_hcd:usb3 21: 231 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb1 22: 26 0 0 0 0 0 0 0 IO-APIC-level uhci_hcd:usb2 23: 3 0 0 0 0 0 0 0 IO-APIC-level ehci_hcd:usb4 24: 348 0 0 0 0 0 0 0 IO-APIC-level eth0 25: 6 192 0 0 0 0 0 0 IO-APIC-level eth1 NMI: 0 0 0 0 0 0 0 0 LOC: 107981 107636 108899 108698 108489 108326 108331 108254 ERR: 7 MIS: 0 Not only we see the card in the last I/O APIC, but we are not even close to using up available IRQs, since we didn't waste any. Signed-off-by:Natalie Protasevich <Natalie.Protasevich@unisys.com> Acked-by:
Andi Kleen <ak@suse.de> Signed-off-by:
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Jan Beulich authored
Eliminate duplicate definition of rdpmc in x86-64's mtrr.h. Signed-off-by:
Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@muc.de> Signed-off-by:
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Roland McGrath authored
This is the x86_64 version of the signal fix I just posted for i386. This problem was first noticed on PPC and has already been fixed there. But the exact same issue applies to other platforms in the same way. The signal blocking for sa_mask and the handled signal takes place after the handler setup. When the stack is bogus, the handler setup forces a SIGSEGV. But then this will be blocked, and returning to user mode will fault again and iterate. This patch fixes the problem by checking whether signal handler setup failed, and not doing the signal-blocking if so. This copies what was done in the ppc code. I think all architectures' signal handler setup code follows this pattern and needs the change. Signed-off-by:
Roland McGrath <roland@redhat.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by:
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john stultz authored
Currently the x86-64 HPET code assumes the entire HPET implementation from the spec is present. This breaks on boxes that do not implement the optional legacy timer replacement functionality portion of the spec. This patch fixes this issue, allowing x86-64 systems that cannot use the HPET for the timer interrupt and RTC to still use the HPET as a time source. I've tested this patch on a system systems without HPET, with HPET but without legacy timer replacement, as well as HPET with legacy timer replacement. This version adds a minor check to cap the HPET counter value in gettimeoffset_hpet to avoid possible time inconsistencies. Please ignore the A2 version I sent to you earlier. Acked-by:
Andi Kleen <ak@muc.de> Signed-off-by:
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Alexander Nyberg authored
Cc: Andi Kleen <ak@muc.de> Signed-off-by:
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Andrew Morton authored
Consolidate the mtrr sanity checking, add a dump_stack(). Signed-off-by:
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Andrew Morton authored
x86_64's cpu_khz is unsigned int and there is no reason why x86 needs to use unsigned long. So make cpu_khz unsigned int on x86 as well. Signed-off-by:
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Alexey Dobriyan authored
* EXPORT_SYMBOL's moved to other files * #include <linux/config.h>, <linux/module.h> where needed * #include's in i386_ksyms.c cleaned up * After copy-paste, redundant due to Makefiles rules preprocessor directives removed: #ifdef CONFIG_FOO EXPORT_SYMBOL(foo); #endif obj-$(CONFIG_FOO) += foo.o * Tiny reformat to fit in 80 columns Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
csum_and_copy_to_user is static inline and uses VERIFY_WRITE. Patch allows to remove asm/uaccess.h from i386_ksyms.c without dependency surprises. Signed-off-by:
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Aleksey Gorelov authored
According to the VIA 82C586B datasheet (still available from http://gkernel.sourceforge.net/specs/via/586b.pdf.bz2) this chip need a special PIRQ mapping. Signed-off-by:
Karsten Keil <kkeil@suse.de> Signed-off-by:
Aleksey Gorelov <aleksey_gorelov@phoenix.com> Signed-off-by:
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Natalie Protasevich authored
I have submitted the patch for x86_64, this is submission for i386. The patch changes the way IRQs are handed out to PCI devices. Currently, each I/O APIC pin gets associated with an IRQ, no matter if the pin is used or not. This imposes severe limitation on systems that have designs that employ many I/O APICs, only utilizing couple lines of each, such as P64H2 chipset. It is used in ES7000, and currently, there is no way to boot the system with more that 9 I/O APICs. The simple change below allows to boot a system with say 64 (or more) I/O APICs, each providing 1 slot, which otherwise impossible because of the IRQ gaps created for unused lines on each I/O APIC. It does not resolve the problem with number of devices that exceeds number of possible IRQs, but eases up a tension for IRQs on any large system with potentually large number of devices. Signed-off-by:
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Christoph Lameter authored
It allows a selectable timer interrupt frequency of 100, 250 and 1000 HZ. Reducing the timer frequency may have important performance benefits on large systems. Signed-off-by:
Christoph Lameter <clameter@sgi.com> Signed-off-by:
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Christoph Lameter authored
Make the timer frequency selectable. The timer interrupt may cause bus and memory contention in large NUMA systems since the interrupt occurs on each processor HZ times per second. Signed-off-by:
Christoph Lameter <christoph@lameter.com> Signed-off-by:
Shai Fultheim <shai@scalex86.org> Signed-off-by:
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Jan Beulich authored
Allow early printk code to take advantage of the full size of the screen, not just the first 25 lines. Signed-off-by:
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Jan Beulich authored
Get the i386 watchdog tick calculation into a state where it can also be used on CPUs with frequencies beyond 4GHz, and it consolidates the calculation into a single place (for potential furture adjustments). Signed-off-by:
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Natalie Protasevich authored
This patch is per Andi's request to remove NO_IOAPIC_CHECK from genapic and use heuristics to prevent unique I/O APIC ID check for systems that don't need it. The patch disables unique I/O APIC ID check for Xeon-based and other platforms that don't use serial APIC bus for interrupt delivery. Andi stated that AMD systems don't need unique IO_APIC_IDs either. Signed-off-by:
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