- 13 Jan, 2011 40 commits
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Alexander Gordeev authored
Add parallel port PPS client. It uses a standard method for capturing timestamps for assert edge transitions: getting a timestamp soon after an interrupt has happened. This is not a very precise source of time information due to interrupt handling delays. However, timestamps for clear edge transitions are much more precise because the interrupt handler continuously polls hardware port until the transition is done. Hardware port operations require only about 1us so the maximum error should not exceed this value. This was my primary goal when developing this client. Clear edge capture could be disabled using clear_wait parameter. Signed-off-by:
Alexander Gordeev <lasaine@lvk.cs.msu.su> Acked-by:
Rodolfo Giometti <giometti@linux.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Alexander Gordeev authored
Add an optional feature of PPSAPI, kernel consumer support, which uses the added hardpps() function. Signed-off-by:
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Alexander Gordeev authored
MONOTONIC_RAW clock timestamps are ideally suited for frequency calculation and also fit well into the original NTP hardpps design. Now phase and frequency can be adjusted separately: the former based on REALTIME clock and the latter based on MONOTONIC_RAW clock. A new function getnstime_raw_and_real is added to timekeeping subsystem to capture both timestamps at the same time and atomically. Signed-off-by:
John Stultz <johnstul@us.ibm.com> Cc: Rodolfo Giometti <giometti@enneenne.com> Signed-off-by:
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Alexander Gordeev authored
This commit adds hardpps() implementation based upon the original one from the NTPv4 reference kernel code from David Mills. However, it is highly optimized towards very fast syncronization and maximum stickness to PPS signal. The typical error is less then a microsecond. To make it sync faster I had to throw away exponential phase filter so that the full phase offset is corrected immediately. Then I also had to throw away median phase filter because it gives a bigger error itself if used without exponential filter. Maybe we will find an appropriate filtering scheme in the future but it's not necessary if the signal quality is ok. Signed-off-by:
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Alexander Gordeev authored
Remove the code that gatheres timestamp in pps_tty_dcd_change() in case passed ts parameter is NULL because it never happens in the current code. Fix comments as well. Signed-off-by:
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Alexander Gordeev authored
Bitwise conjunction is distributive so we can simplify some conditions. Signed-off-by:
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Alexander Gordeev authored
This way less overhead is involved when running production kernel. If you want to debug a pps client module please define DEBUG to enable the checks. Signed-off-by:
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Alexander Gordeev authored
Now pps_idr_lock is never used in interrupt context so we can replace spin_lock_irq/spin_unlock_irq with plain spin_lock/spin_unlock. But there is also a potential race condition when someone can steal an id which was allocated by idr_pre_get before it is used. So convert spin lock to mutex and protect the whole id generation process. Signed-off-by:
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Alexander Gordeev authored
Since now idr is only used to manage char device id's and not used in kernel API anymore it should be moved to pps.c. This also makes it possible to release id only at actual device freeing so nobody can register a pps device with the same id while our device is not freed yet. Signed-off-by:
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Alexander Gordeev authored
Since we now have direct pointers to struct pps_device everywhere it's easy to use dev_* functions to print messages instead of plain printks. Where dev_* cannot be used printks are converted to pr_*. Signed-off-by:
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Alexander Gordeev authored
Using device index as a pointer needs some unnecessary work to be done every time the pointer is needed (in irq handler for example). Using a direct pointer is much more easy (and safe as well). Signed-off-by:
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Alexander Gordeev authored
Add a helper function to gather timestamps. This way clients don't have to duplicate it. Signed-off-by:
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Alexander Gordeev authored
There was a race in PPS_FETCH ioctl handler when several processes want to obtain PPS data simultaneously using sleeping PPS_FETCH. They all sleep most of the time in the system call. With the old approach when the first process waiting on the pps queue is waken up it makes new system call right away and zeroes pps->go. So other processes continue to sleep. This is a clear race condition because of the global 'go' variable. With the new approach pps->last_ev holds some value increasing at each PPS event. PPS_FETCH ioctl handler saves current value to the local variable at the very beginning so it can safely check that there is a new event by just comparing both variables. Signed-off-by:
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Alexander Gordeev authored
Move variable declarations where they are used in pps_cdev_ioctl. Signed-off-by:
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Alexander Gordeev authored
Here are some very trivial fixes combined: - add macro definitions to protect header file from including several times - remove declaration for an unexistent array - fix typos Signed-off-by:
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Jeff Mahoney authored
Commit 4be2c95d ("taskstats: pad taskstats netlink response for aligment issues on ia64") added a null field to align the taskstats structure but the discussion centered around ia64. The issue exists on other platforms with inefficient unaligned access and adding them piecemeal would be an unmaintainable mess. This patch uses Dave Miller's suggestion of using a combination of CONFIG_64BIT && !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to determine whether alignment is needed. Note that this will cause breakage on those platforms with applications like iotop which had hard-coded offsets into the packet to access the taskstats structure. The message seen on systems without the alignment fixes looks like: kernel unaligned access to 0xe000023879dca9bc, ip=0xa000000100133d10 The addresses may vary but resolve to locations inside __delayacct_add_tsk. iotop makes what I'd call unreasonable assumptions about the contents of a netlink genetlink packet containing generic attributes. They're typed and have headers that specify value lengths, so the client can (should) identify and skip the ones the client doesn't understand. The kernel, as of version 2.6.36, presented a packet like so: +--------------------------------+ | genlmsghdr - 4 bytes | +--------------------------------+ | NLA header - 4 bytes | /* Aggregate header */ +-+------------------------------+ | | NLA header - 4 bytes | /* PID header */ | +------------------------------+ | | pid/tgid - 4 bytes | | +------------------------------+ | | NLA header - 4 bytes | /* stats header */ | + -----------------------------+ <- oops. aligned on 4 byte boundary | | struct taskstats - 328 bytes | +-+------------------------------+ The iotop code expects that the kernel will behave as it did then, assuming that the packet format is set in stone. The format is set in stone, but the packet offsets are not. There's nothing in the packet format that guarantees that the packet will be sent in exactly the same way. The attribute contents are set (or versioned) and the aggregate contents are set but they can be anywhere in the packet. The issue here isn't that an unaligned structure gets passed to userspace, it's that the NLA infrastructure has something of a weakness: The 4 byte attribute header may force the payload to be unaligned. The taskstats structure is created at an unaligned location and then 64-bit values are operated on inside the kernel, so the unaligned access warnings gets spewed everywhere. It's possible to use the unaligned access API to operate on the structure in the kernel but it seems like a wasted effort to work around userspace code that isn't following the packet format. Any new additions would also need the be worked around. It's a maintenance nightmare. The conclusion of the earlier discussion seemed to be "ok fine, if we have to break it, don't break it on arches that don't have the problem." Dave pointed out that the unaligned access problem doesn't only exist on ia64, but also on other 64-bit arches that don't have efficient unaligned access and it should be fixed there as well. The committed version of the patch and this addition keep with the conclusion of that discussion not to break it unnecessarily, which the pid padding and the packet padding fixes did do. x86_64 and powerpc don't suffer this problem so they shouldn't suffer the solution. Other 64-bit architectures do and will, though. Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Reported-by:
David S. Miller <davem@davemloft.net> Acked-by:
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Matti J. Aaltonen authored
Creates a new "Near Field Communication" subsystem in drivers/nfc. http://en.wikipedia.org/wiki/Near_Field_Communication is useful ;) This is a driver for the pn544 NFC device. The driver transfers ETSI messages between the device and the user space. Signed-off-by:
Matti J. Aaltonen <matti.j.aaltonen@nokia.com> Signed-off-by:
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Pavel Emelyanov authored
Currently on 64-bit arch the user_namespace is 2096 and when being kmalloc-ed it resides on a 4k slab wasting 2003 bytes. If we allocate a separate cache for it and reduce the hash size from 128 to 64 chains the packaging becomes *much* better - the struct is 1072 bytes and the hole between is 98 bytes. [akpm@linux-foundation.org: s/__initcall/module_init/] Signed-off-by:
Pavel Emelyanov <xemul@openvz.org> Acked-by:
Serge E. Hallyn <serge@hallyn.com> Signed-off-by:
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Jovi Zhang authored
ctl_unnumbered.txt have been removed in Documentation directory so just also remove this invalid comments [akpm@linux-foundation.org: fix Documentation/sysctl/00-INDEX, per Dave] Signed-off-by:
Jovi Zhang <bookjovi@gmail.com> Cc: Dave Young <hidave.darkstar@gmail.com> Acked-by:
WANG Cong <xiyou.wangcong@gmail.com> Signed-off-by:
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Jovi Zhang authored
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Thomas Taranowski authored
In fsl_rio_dbell_handler() the code currently simply acknowledges the QFI queue full interrupt, but does nothing to resolve the queue full condition. Instead, it jumps to the end of the isr. When a queue full condition occurs, the isr is then re-entered immediately and continually, forever. The fix is to just fall through and read out current doorbell entries. Signed-off-by:
Thomas Taranowski <tom@baringforge.com> Cc: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Li Yang <leoli@freescale.com> Cc: Thomas Moll <thomas.moll@sysgo.com> Cc: Micha Nelissen <micha@neli.hopto.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: <stable@kernel.org> Signed-off-by:
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Alexandre Bounine authored
Add new sRIO switch device IDs and enable a basic support for them. Signed-off-by:
Alexandre Bounine <alexandre.bounine@idt.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Li Yang <leoli@freescale.com> Cc: Thomas Moll <thomas.moll@sysgo.com> Cc: Micha Nelissen <micha@neli.hopto.org> Signed-off-by:
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Alexandre Bounine authored
Change the way how switchid value is set. Local counter variable does not provide unified way to identify switch devices in a system with multiple processors. Using local counter leads to the situation when the same RIO switch has different switch ID for each processor. Replacing local counter with unique portion of the Component Tag provides unified reference to the switch by every processor in the system. Signed-off-by:
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Alexandre Bounine authored
Add setting links between rio_dev objects into the discovery process. This needed to report device connections on agent (non-host) processors that perform RIO discovery. Originally, these links have been introduced for enumerating host only to support error management. Signed-off-by:
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Alexandre Bounine authored
Add definition of the unique device identifier field in the component tag. RIO_CTAG_UDEVID does not take all 32 bits of the component tag value to allow future extensions to the component tag use. Selected size of the RIO_CTAG_UDEVID field (17 bits) is sufficient to accommodate maximum number of endpoints in large RIO network (16-bit id) plus switches. Signed-off-by:
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Alexandre Bounine authored
Convert RIO switches device structures (rio_dev + rio_switch) into a single allocation unit. This change is based on the fact that RIO switches are using common RIO device objects anyway. Allocating RIO switch objects as RIO devices with added space for switch information simplifies handling of RIO switch devices. Signed-off-by:
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Alexandre Bounine authored
Change code to use one storage location common for switches and endpoints. This eliminates unnecessary device type checks during basic access operations. Logic that assigns destid to RIO devices stays unchanged - as before, switches use an associated destid because they do not have their own. Signed-off-by:
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Namhyung Kim authored
Commit 66fa12c5 ("ieee1394: remove the old IEEE 1394 driver stack") eliminated the only user of cdev_index(). So it can be removed too. Signed-off-by:
Namhyung Kim <namhyung@gmail.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by:
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Dave Anderson authored
Commit 34aacb29 ("procfs: Use generic_file_llseek in /proc/kcore") broke seeking on /proc/kcore. This changes it back to use default_llseek in order to restore the original behavior. The problem with generic_file_llseek is that it only allows seeks up to inode->i_sb->s_maxbytes, which is 2GB-1 on procfs, where the memory file offset values in the /proc/kcore PT_LOAD segments may exceed or start beyond that offset value. A similar revert was made for /proc/vmcore. Signed-off-by:
Dave Anderson <anderson@redhat.com> Acked-by:
Frederic Weisbecker <fweisbec@gmail.com> Cc: <stable@kernel.org> Signed-off-by:
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Alexey Dobriyan authored
Filename is supposed to match procfile name for random junk. Add __init while I'm at it. Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
For the common case where a proc entry is being removed and nobody is in the process of using it, save a LOCK/UNLOCK pair. Signed-off-by:
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Petr Holasek authored
Add a PageSlab() check before adding the _mapcount value to /kpagecount. page->_mapcount is in a union with the SLAB structure so for pages controlled by SLAB, page_mapcount() returns nonsense. Signed-off-by:
Petr Holasek <pholasek@redhat.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by:
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Jovi Zhang authored
single_open()'s third argument is for copying into seq_file->private. Use that, rather than open-coding it. Signed-off-by:
David Rientjes <rientjes@google.com> Acked-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
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Alexey Dobriyan authored
- ->low_ino is write-once field -- reading it under locks is unnecessary. - /proc/$PID stuff never reaches pde_put()/free_proc_entry() -- PROC_DYNAMIC_FIRST check never triggers. - in proc_get_inode(), inode number always matches proc dir entry, so save one parameter. Signed-off-by:
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Alexey Dobriyan authored
For string without format specifiers, use seq_puts(). For seq_printf("\n"), use seq_putc('\n'). text data bss dec hex filename 61866 488 112 62466 f402 fs/proc/proc.o 61729 488 112 62329 f379 fs/proc/proc.o ---------------------------------------------------- -139 Signed-off-by: -
Alexey Dobriyan authored
/proc/*/statm code needlessly truncates data from unsigned long to int. One needs only 8+ TB of RAM to make truncation visible. Signed-off-by:
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Joe Perches authored
Use temporary lr for struct latency_record for improved readability and fewer columns used. Removed trailing space from output. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Joe Perches <joe@perches.com> Cc: Jiri Kosina <trivial@kernel.org> Signed-off-by:
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Trevor Woerner authored
The 'ns' cgroup is considered deprecated. Change the cgroup subsystem used in the examples of the cgroup documentation from 'ns' to 'blkio'. Signed-off-by:
Trevor Woerner <twoerner@gmail.com> Acked-by:
Li Zefan <lizf@cn.fujitsu.com> Acked-by:
Paul Menage <menage@google.com> Signed-off-by:
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Rob Landley authored
Show how to install the "toggle wordwrap" extension in thunderbird. Signed-off-by:
Rob Landley <rlandley@parallels.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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Lasse Collin authored
Signed-off-by:
Lasse Collin <lasse.collin@tukaani.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by:
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