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* uml: pcap devices should get MACs from command lineJeff Dike2007-05-08
| | | | | | | | | | | Allow a pcap device to be assigned a MAC on the command line. They don't really need one, but it is handy to be able to do when your distro assigns a new ethernet device whenever it sees a new MAC. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: network and pcap cleanupJeff Dike2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some network device cleanup. When setup_etheraddr found a globally valid MAC being assigned to an interface, it went ahead and used it rather than assigning a random MAC like the other cases do. This isn't really an error like the others, but it seems consistent to make it behave the same. We were getting some duplicate kfree() in the error case in eth_configure because platform_device_unregister frees buffers that the error cases following tried to free again. The pcap initialization routine wasn't doing the proper printk of its information, causing a printk of the first part of that line to be unterminated by a newline. The pcap code had a bunch of style violations, which are now fixed. pcap_setup wasn't returning false when it detected an unrecognized option. The printks in pcap_user all got UM_KERN_BLAH prepended to their format strings. pcap_remove now checks for a non-NULL pcap structure before it calls pcap_close. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: create asm/cmpxchg.hJeff Dike2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | i386: Rearrange the cmpxchg code to allow atomic.h to get it without needing to include system.h. This kills warnings in the UML build from atomic.h about implicit declarations of cmpxchg symbols. The i386 build presumably isn't seeing this because a separate inclusion of system.h is covering it over. The cmpxchg stuff is moved to asm-i386/cmpxchg.h, with an include left in system.h for the benefit of generic code which expects cmpxchg there. Meanwhile, atomic.h includes cmpxchg.h. This causes no noticable damage to the i386 build. x86_64: Move cmpxchg into its own header. atomic.h already included system.h, so this is changed to include cmpxchg.h. This is purely cleanup - it's not fixing any warnings - so if the x86_64 system.h isn't considered as cleanup-worthy as i386, then this can be dropped. It causes no noticable damage to the x86_64 build. uml: The i386 and x86_64 cmpxchg patches require an asm-um/cmpxchg.h for the UML build. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove tas()Jeff Dike2007-05-08
| | | | | | | | | | tas() has no users, so get rid of it. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Cc: <linux-arch@vger.kernel.org> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: x86_64 extensionMathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: sparc64 cleanupMathieu Desnoyers2007-05-08
| | | | | | | | | sparc64 local_t cleanup : simply use asm-generic/local.h. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: powerpc extensionMathieu Desnoyers2007-05-08
| | | | | | | | | [akpm@linux-foundation.org: build fixes] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: parisc cleanupMathieu Desnoyers2007-05-08
| | | | | | | | | | | parisc architecture local_t cleanup : use asm-generic/local.h. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <willy@debian.org> Cc: Grant Grundler <grundler@parisc-linux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: mips extensionMathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: ia64 extensionMathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: i386 extensionMathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: alpha extensionMathieu Desnoyers2007-05-08
| | | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Richard Henderson <rth@twiddle.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* local_t: architecture independent extensionMathieu Desnoyers2007-05-08
| | | | | | | | | | | | | | | | | This series extena and standardises local_t operations on each architecture, allowing a rich set of atomic operations to be done on per-cpu data with minimal performance impact. On architectures where there seems to be no difference between the SMP and UP operation (same memory barriers, same LOCKing), local.h simply includes asm-generic/local.h, which removes duplicated code from the current kernel tree. This patch: local_t: architecture independent extension Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: atomic_add_unless as inline. Remove system.h atomic.h circular ↵Mathieu Desnoyers2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | dependency atomic_add_unless as inline. Remove system.h atomic.h circular dependency. I agree (with Andi Kleen) this typeof is not needed and more error prone. All the original atomic.h code that uses cmpxchg (which includes the atomic_add_unless) uses defines instead of inline functions, probably to circumvent a circular dependency between system.h and atomic.h on powerpc (which my patch addresses). Therefore, it makes sense to use inline functions that will provide type checking. atomic_add_unless as inline. Remove system.h atomic.h circular dependency. Digging into the FRV architecture shows me that it is also affected by such a circular dependency. Here is the diff applying this against the rest of my atomic.h patches. It applies over the atomic.h standardization patches. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to x86_64Mathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to sparc64Mathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to powerpcMathieu Desnoyers2007-05-08
| | | | | | | | | [akpm@linux-foundation.org: build fixes] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to pariscMathieu Desnoyers2007-05-08
| | | | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Matthew Wilcox <willy@debian.org> Acked-by: Grant Grundler <grundler@parisc-linux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to mipsMathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to ia64Mathieu Desnoyers2007-05-08
| | | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: i386 type safety fixMathieu Desnoyers2007-05-08
| | | | | | | | | | | | | Remove an explicit cast to an integer type for the result returned by cmpxchg. It is not per se a problem on the i386 architecture, because sizeof(int) == sizeof(long), but whenever this code is cut'n'pasted to a accept passing an atomic64_t value as parameter to cmpxchg, xchg and add_unless, having 64 bits inputs casted to 32 bits. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: complete atomic_long operations in asm-genericMathieu Desnoyers2007-05-08
| | | | | | Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* atomic.h: add atomic64 cmpxchg, xchg and add_unless to alphaMathieu Desnoyers2007-05-08
| | | | | | | | | | | | | | | | | This series mainly adds support for missing 64 bits cmpxchg and 64 bits atomic add unless. Therefore, principally 64 bits architectures are targeted by these patches. It also adds the complete list of atomic operations on the atomic_long type. This patch: atomic.h: add atomic64 cmpxchg, xchg and add_unless to alpha Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Kprobes: The ON/OFF knob thru debugfsAnanth N Mavinakayanahalli2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch provides a debugfs knob to turn kprobes on/off o A new file /debug/kprobes/enabled indicates if kprobes is enabled or not (default enabled) o Echoing 0 to this file will disarm all installed probes o Any new probe registration when disabled will register the probe but not arm it. A message will be printed out in such a case. o When a value 1 is echoed to the file, all probes (including ones registered in the intervening period) will be enabled o Unregistration will happen irrespective of whether probes are globally enabled or not. o Update Documentation/kprobes.txt to reflect these changes. While there also update the doc to make it current. We are also looking at providing sysrq key support to tie to the disabling feature provided by this patch. [akpm@linux-foundation.org: Use bool like a bool!] [akpm@linux-foundation.org: add printk facility levels] [cornelia.huck@de.ibm.com: Add the missing arch_trampoline_kprobe() for s390] Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: kretprobes simplificationsChristoph Hellwig2007-05-08
| | | | | | | | | | | | | | | | | - consolidate duplicate code in all arch_prepare_kretprobe instances into common code - replace various odd helpers that use hlist_for_each_entry to get the first elemenet of a list with either a hlist_for_each_entry_save or an opencoded access to the first element in the caller - inline add_rp_inst into it's only remaining caller - use kretprobe_inst_table_head instead of opencoding it Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: codingstyle cleanupsChristoph Hellwig2007-05-08
| | | | | | | | | | | Remove superflous braces and fix indentation aswell as comments. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kprobes: use hlist_for_each_entryChristoph Hellwig2007-05-08
| | | | | | | | | Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc-cmos: make it load on PNPBIOS systemsMarko Vrh2007-05-08
| | | | | | | | | | Replace CONFIG_PNPACPI with CONFIG_PNP, so it loads on ACPI-less PNPBIOS systems. Signed-off-by: Marko Vrh <mvrh@freeshells.ch> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: remove "RTC_ALM_SET mode" bugsDavid Brownell2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a common glitch in how RTC drivers handle two "set alarm" modes, by getting rid of the surprising/hidden one that was rarely implemented correctly (and which could expose nonportable hardware-specific behavior). The glitch comes from the /dev/rtcX logic implementing the legacy RTC_ALM_SET (limited to 24 hours, needing RTC_AIE_ON) ioctl on top of the RTC driver call providing access to the newer RTC_WKALM_SET (without those limitations) by initializing the day/month/year fields to be invalid ... that second mode. Now, since few RTC drivers check those fields, and most hardware misbehaves when faced with invalid date fields, many RTC drivers will set bogus alarm times on those RTC_ALM_SET code paths. (Several in-tree drivers have that issue, and I also noticed it with code reviews on several new RTC drivers.) This patch ensures that RTC drivers never see such invalid alarm fields, by moving some logic out of rtc-omap into the RTC_ALM_SET code and adding an explicit check (which will prevent the issue on other code paths). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Scott Wood <scottwood@freescale.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "rtc: Add rtc_merge_alarm()"Andrew Morton2007-05-08
| | | | | | | | | | | | | David says "884b4aaaa242a2db8c8252796f0118164a680ab5 should be reverted. It added an rtc_merge_alarm() call to the 2.6.20 kernel, which hasn't yet been used by any in-tree driver; this patch obviates the need for that call, and uses a more robust approach." Cc: Scott Wood <scottwood@freescale.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* workaround rtc-related acpi table bugsDavid Brownell2007-05-08
| | | | | | | | | | | | | | | | This works around a bug seen in some RTC-related ACPI table entries, and tweaks related diagnostics to follow the ACPI convention. The bug prevents misleading boot-time messages: platforms affected by this bug wrongly report they can support alarms up to one year in the future, when in fact the longest alarm is just 24 hours. That will surprise anyone trying to use those extended alarms. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ACPI wakeup hooks for rtc-cmosDavid Brownell2007-05-08
| | | | | | | | | | | Remove /proc/acpi/alarm file when the rtc-cmos "wakealarm" file is available. Instead, provide hooks that rtc-cmos will use. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc-cmos wakeup interfaceDavid Brownell2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I finally got around to testing the updated wakeup event hooks for rtc-cmos, and they follow in two patches: - Interface update ... when a simple enable_irq_wake() doesn't suffice, the platform data can hold suspend/resume callback hooks. - ACPI implementation ... provides callback hooks to do ACPI magic, and eliminate the legacy /proc/acpi/alarm file. The interface update could go into 2.6.21, but that's not essential; they will be NOPs on most PCs, without the ACPI stuff. I suspect the ACPI folk may have opinions about how to merge that second patch, and how to obsolete that legacy procfs file. I'd like to see that merge into 2.6.22 if possible... As for how to kick it in ... two ways: - The appended "rtcwake" program; updated since the last time it was posted, it deals much better with timezones and DST. - Write the /sys/class/rtc/.../wakealarm file, then go to sleep. For some reason RTC wake from "swsusp" stopped working on a system where it previously worked; the alarm setting appears to get clobbered. But on the bright side, RTC wake from "standby" worked on a system that had never been able to resume from that state before ... IDEACPI is my guess as to why it finally started to work. It's the old "two steps forward, one step back" dance, I guess. - Dave /* gcc -Wall -Os -o rtcwake rtcwake.c */ #include <stdio.h> #include <getopt.h> #include <fcntl.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <errno.h> #include <time.h> #include <sys/ioctl.h> #include <sys/time.h> #include <sys/types.h> #include <linux/rtc.h> /* constants from legacy PC/AT hardware */ #define RTC_PF 0x40 #define RTC_AF 0x20 #define RTC_UF 0x10 /* * rtcwake -- enter a system sleep state until specified wakeup time. * * This uses cross-platform Linux interfaces to enter a system sleep state, * and leave it no later than a specified time. It uses any RTC framework * driver that supports standard driver model wakeup flags. * * This is normally used like the old "apmsleep" utility, to wake from a * suspend state like ACPI S1 (standby) or S3 (suspend-to-RAM). Most * platforms can implement those without analogues of BIOS, APM, or ACPI. * * On some systems, this can also be used like "nvram-wakeup", waking * from states like ACPI S4 (suspend to disk). Not all systems have * persistent media that are appropriate for such suspend modes. * * The best way to set the system's RTC is so that it holds the current * time in UTC. Use the "-l" flag to tell this program that the system * RTC uses a local timezone instead (maybe you dual-boot MS-Windows). */ static char *progname; #ifdef DEBUG #define VERSION "1.0 dev (" __DATE__ " " __TIME__ ")" #else #define VERSION "0.9" #endif static unsigned verbose; static int rtc_is_utc = -1; static int may_wakeup(const char *devname) { char buf[128], *s; FILE *f; snprintf(buf, sizeof buf, "/sys/class/rtc/%s/device/power/wakeup", devname); f = fopen(buf, "r"); if (!f) { perror(buf); return 0; } fgets(buf, sizeof buf, f); fclose(f); s = strchr(buf, '\n'); if (!s) return 0; *s = 0; /* wakeup events could be disabled or not supported */ return strcmp(buf, "enabled") == 0; } /* all times should be in UTC */ static time_t sys_time; static time_t rtc_time; static int get_basetimes(int fd) { struct tm tm; struct rtc_time rtc; /* this process works in RTC time, except when working * with the system clock (which always uses UTC). */ if (rtc_is_utc) setenv("TZ", "UTC", 1); tzset(); /* read rtc and system clocks "at the same time", or as * precisely (+/- a second) as we can read them. */ if (ioctl(fd, RTC_RD_TIME, &rtc) < 0) { perror("read rtc time"); return 0; } sys_time = time(0); if (sys_time == (time_t)-1) { perror("read system time"); return 0; } /* convert rtc_time to normal arithmetic-friendly form, * updating tm.tm_wday as used by asctime(). */ memset(&tm, 0, sizeof tm); tm.tm_sec = rtc.tm_sec; tm.tm_min = rtc.tm_min; tm.tm_hour = rtc.tm_hour; tm.tm_mday = rtc.tm_mday; tm.tm_mon = rtc.tm_mon; tm.tm_year = rtc.tm_year; tm.tm_isdst = rtc.tm_isdst; /* stays unspecified? */ rtc_time = mktime(&tm); if (rtc_time == (time_t)-1) { perror("convert rtc time"); return 0; } if (verbose) { if (!rtc_is_utc) { printf("\ttzone = %ld\n", timezone); printf("\ttzname = %s\n", tzname[daylight]); gmtime_r(&rtc_time, &tm); } printf("\tsystime = %ld, (UTC) %s", (long) sys_time, asctime(gmtime(&sys_time))); printf("\trtctime = %ld, (UTC) %s", (long) rtc_time, asctime(&tm)); } return 1; } static int setup_alarm(int fd, time_t *wakeup) { struct tm *tm; struct rtc_wkalrm wake; tm = gmtime(wakeup); wake.time.tm_sec = tm->tm_sec; wake.time.tm_min = tm->tm_min; wake.time.tm_hour = tm->tm_hour; wake.time.tm_mday = tm->tm_mday; wake.time.tm_mon = tm->tm_mon; wake.time.tm_year = tm->tm_year; wake.time.tm_wday = tm->tm_wday; wake.time.tm_yday = tm->tm_yday; wake.time.tm_isdst = tm->tm_isdst; /* many rtc alarms only support up to 24 hours from 'now' ... */ if ((rtc_time + (24 * 60 * 60)) > *wakeup) { if (ioctl(fd, RTC_ALM_SET, &wake.time) < 0) { perror("set rtc alarm"); return 0; } if (ioctl(fd, RTC_AIE_ON, 0) < 0) { perror("enable rtc alarm"); return 0; } /* ... so use the "more than 24 hours" request only if we must */ } else { /* avoid an extra AIE_ON call */ wake.enabled = 1; if (ioctl(fd, RTC_WKALM_SET, &wake) < 0) { perror("set rtc wake alarm"); return 0; } } return 1; } static void suspend_system(const char *suspend) { FILE *f = fopen("/sys/power/state", "w"); if (!f) { perror("/sys/power/state"); return; } fprintf(f, "%s\n", suspend); fflush(f); /* this executes after wake from suspend */ fclose(f); } int main(int argc, char **argv) { static char *devname = "rtc0"; static unsigned seconds = 0; static char *suspend = "standby"; int t; int fd; time_t alarm = 0; progname = strrchr(argv[0], '/'); if (progname) progname++; else progname = argv[0]; if (chdir("/dev/") < 0) { perror("chdir /dev"); return 1; } while ((t = getopt(argc, argv, "d:lm:s:t:uVv")) != EOF) { switch (t) { case 'd': devname = optarg; break; case 'l': rtc_is_utc = 0; break; /* what system power mode to use? for now handle only * standardized mode names; eventually when systems define * their own state names, parse /sys/power/state. * * "on" is used just to test the RTC alarm mechanism, * bypassing all the wakeup-from-sleep infrastructure. */ case 'm': if (strcmp(optarg, "standby") == 0 || strcmp(optarg, "mem") == 0 || strcmp(optarg, "disk") == 0 || strcmp(optarg, "on") == 0 ) { suspend = optarg; break; } printf("%s: unrecognized suspend state '%s'\n", progname, optarg); goto usage; /* alarm time, seconds-to-sleep (relative) */ case 's': t = atoi(optarg); if (t < 0) { printf("%s: illegal interval %s seconds\n", progname, optarg); goto usage; } seconds = t; break; /* alarm time, time_t (absolute, seconds since 1/1 1970 UTC) */ case 't': t = atoi(optarg); if (t < 0) { printf("%s: illegal time_t value %s\n", progname, optarg); goto usage; } alarm = t; break; case 'u': rtc_is_utc = 1; break; case 'v': verbose++; break; case 'V': printf("%s: version %s\n", progname, VERSION); break; default: usage: printf("usage: %s [options]" "\n\t" "-d rtc0|rtc1|...\t(select rtc)" "\n\t" "-l\t\t\t(RTC uses local timezone)" "\n\t" "-m standby|mem|...\t(sleep mode)" "\n\t" "-s seconds\t\t(seconds to sleep)" "\n\t" "-t time_t\t\t(time to wake)" "\n\t" "-u\t\t\t(RTC uses UTC)" "\n\t" "-v\t\t\t(verbose messages)" "\n\t" "-V\t\t\t(show version)" "\n", progname); return 1; } } if (!alarm && !seconds) { printf("%s: must provide wake time\n", progname); goto usage; } /* REVISIT: if /etc/adjtime exists, read it to see what * the util-linux version of hwclock assumes. */ if (rtc_is_utc == -1) { printf("%s: assuming RTC uses UTC ...\n", progname); rtc_is_utc = 1; } /* this RTC must exist and (if we'll sleep) be wakeup-enabled */ fd = open(devname, O_RDONLY); if (fd < 0) { perror(devname); return 1; } if (strcmp(suspend, "on") != 0 && !may_wakeup(devname)) { printf("%s: %s not enabled for wakeup events\n", progname, devname); return 1; } /* relative or absolute alarm time, normalized to time_t */ if (!get_basetimes(fd)) return 1; if (verbose) printf("alarm %ld, sys_time %ld, rtc_time %ld, seconds %u\n", alarm, sys_time, rtc_time, seconds); if (alarm) { if (alarm < sys_time) { printf("%s: time doesn't go backward to %s", progname, ctime(&alarm)); return 1; } alarm += sys_time - rtc_time; } else alarm = rtc_time + seconds + 1; if (setup_alarm(fd, &alarm) < 0) return 1; sync(); printf("%s: wakeup from \"%s\" using %s at %s", progname, suspend, devname, ctime(&alarm)); fflush(stdout); usleep(10 * 1000); if (strcmp(suspend, "on") != 0) suspend_system(suspend); else { unsigned long data; do { t = read(fd, &data, sizeof data); if (t < 0) { perror("rtc read"); break; } if (verbose) printf("... %s: %03lx\n", devname, data); } while (!(data & RTC_AF)); } if (ioctl(fd, RTC_AIE_OFF, 0) < 0) perror("disable rtc alarm interrupt"); close(fd); return 0; } This patch: Make rtc-cmos do the relevant magic so this RTC can wake the system from a sleep state. That magic comes in two basic flavors: - Straightforward: enable_irq_wake(), the way it'd work on most SOC chips; or generally with system sleep states which don't disable core IRQ logic. - Roundabout, using non-IRQ platform hooks. This is needed with ACPI and one almost-clone chip which uses a special wakeup-only alarm. (That's the RTC used on Footbridge boards, FWIW, which don't do PM in Linux.) A separate patch implements those hooks for ACPI platforms, so that rtc_cmos can issue system wakeup events (and its sysfs "wakealarm" attribute works on at least some systems). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: update vr41xx alarm handlingYoichi Yuasa2007-05-08
| | | | | | | | | | | - vr41xx_rtc_read_alarm() reports alarm enabled. - vr41xx_rtc_set_alarm() sets alarm disable/enable by rtc_wkalrm.enabled. Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* RTC Kconfig cleanupAlessandro Zummo2007-05-08
| | | | | | | Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: update to class device removal patchesDavid Brownell2007-05-08
| | | | | | | | | | | | Fix a goof in the revised classdev support for RTCs: make sure the /dev node info is ready before the device is registered, not after. Otherwise the /sys/class/rtc/rtcN/dev attribute won't be created and then udev won't have the information it needs to create the /dev/rtcN node. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* RTC: replace some newly-introduced macros with inlinesDavid Brownell2007-05-08
| | | | | | Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: suspend()/resume() restores system clockDavid Brownell2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | RTC class suspend/resume support, re-initializing the system clock on resume from the clock used to initialize it at boot time. - The reinit-on-resume is hooked to the existing RTC_HCTOSYS config option, on the grounds that a clock good enough for init must also be good enough for re-init. - Inlining a version of the code used by ARM, to save and restore the delta between a selected RTC and the current system wall-clock time. - Removes calls to that ARM code from AT91, OMAP1, and S3C RTCs. This means that systems using those RTCs across suspend/resume will likely want to change their kernel configs to enable RTC_HCTOSYS. If HCTOSYS isn't using a second RTC (with battery?), this changes the system's initial date from Jan 1970 to the epoch this hardware uses: 1998 for AT91, 2000 for OMAP1 (assuming no split power mode), etc. This goes on top of the patch series removing "struct class_device" usage from the RTC framework. That's all needed for class suspend()/resume(). Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: remove rest of class_deviceDavid Brownell2007-05-08
| | | | | | | | | | Finish converting the RTC framework so it no longer uses class_device. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: simplified /proc/driver/rtc handlingDavid Brownell2007-05-08
| | | | | | | | | | | | | | | | | This simplifies the RTC procfs support by removing the class_interface that hooks it into the rtc core. If it's configured, then sysfs support is now part of the RTC core, and is never a separate module. It also removes the class_interface hook, now that its last remaining user is gone. (That API is usable only with a "struct class_device".) It's another step towards being able to remove "struct class_device". Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: simplified rtc sysfs attribute handlingDavid Brownell2007-05-08
| | | | | | | | | | | | | | This simplifies the RTC sysfs support by removing the class_interface that hooks it into the rtc core. If it's configured, then sysfs support is now part of the RTC core, and is never a separate module. It's another step towards being able to remove "struct class_device". Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: rtc interfaces don't use class_deviceDavid Brownell2007-05-08
| | | | | | | | | | | | This patch removes class_device from the programming interface that the RTC framework exposes to the rest of the kernel. Now an rtc_device is passed, which is more type-safe and streamlines all the relevant code. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rtc: remove /sys/class/rtc-dev/*David Brownell2007-05-08
| | | | | | | | | | | | | | | | | This simplifies the /dev support by removing a superfluous class_device (the /sys/class/rtc-dev stuff) and the class_interface that hooks it into the rtc core. Accordingly, if it's configured then /dev support is now part of the RTC core, and is never a separate module. It's another step towards being able to remove "struct class_device". [bunk@stusta.de: drivers/rtc/rtc-dev.c should #include "rtc-core.h"] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-By: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* utimensat implementationUlrich Drepper2007-05-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement utimensat(2) which is an extension to futimesat(2) in that it a) supports nano-second resolution for the timestamps b) allows to selectively ignore the atime/mtime value c) allows to selectively use the current time for either atime or mtime d) supports changing the atime/mtime of a symlink itself along the lines of the BSD lutimes(3) functions For this change the internally used do_utimes() functions was changed to accept a timespec time value and an additional flags parameter. Additionally the sys_utime function was changed to match compat_sys_utime which already use do_utimes instead of duplicating the work. Also, the completely missing futimensat() functionality is added. We have such a function in glibc but we have to resort to using /proc/self/fd/* which not everybody likes (chroot etc). Test application (the syscall number will need per-arch editing): #include <errno.h> #include <fcntl.h> #include <time.h> #include <sys/time.h> #include <stddef.h> #include <syscall.h> #define __NR_utimensat 280 #define UTIME_NOW ((1l << 30) - 1l) #define UTIME_OMIT ((1l << 30) - 2l) int main(void) { int status = 0; int fd = open("ttt", O_RDWR|O_CREAT|O_EXCL, 0666); if (fd == -1) error (1, errno, "failed to create test file \"ttt\""); struct stat64 st1; if (fstat64 (fd, &st1) != 0) error (1, errno, "fstat failed"); struct timespec t[2]; t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); struct stat64 st2; if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0] = st1.st_atim; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_OMIT; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("atim not set"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("mtim changed from zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 0; t[0].tv_nsec = UTIME_OMIT; t[1] = st1.st_mtim; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != st1.st_atim.tv_sec || st2.st_atim.tv_nsec != st1.st_atim.tv_nsec) { puts ("mtim changed from original time"); status = 1; } if (st2.st_mtim.tv_sec != st1.st_mtim.tv_sec || st2.st_mtim.tv_nsec != st1.st_mtim.tv_nsec) { puts ("mtim not set"); status = 1; } if (status != 0) goto out; sleep (2); t[0].tv_sec = 0; t[0].tv_nsec = UTIME_NOW; t[1].tv_sec = 0; t[1].tv_nsec = UTIME_NOW; if (syscall(__NR_utimensat, AT_FDCWD, "ttt", t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); struct timeval tv; gettimeofday(&tv,NULL); if (st2.st_atim.tv_sec <= st1.st_atim.tv_sec || st2.st_atim.tv_sec > tv.tv_sec) { puts ("atim not set to NOW"); status = 1; } if (st2.st_mtim.tv_sec <= st1.st_mtim.tv_sec || st2.st_mtim.tv_sec > tv.tv_sec) { puts ("mtim not set to NOW"); status = 1; } if (symlink ("ttt", "tttsym") != 0) error (1, errno, "cannot create symlink"); t[0].tv_sec = 0; t[0].tv_nsec = 0; t[1].tv_sec = 0; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, AT_FDCWD, "tttsym", t, AT_SYMLINK_NOFOLLOW) != 0) error (1, errno, "utimensat failed"); if (lstat64 ("tttsym", &st2) != 0) error (1, errno, "lstat failed"); if (st2.st_atim.tv_sec != 0 || st2.st_atim.tv_nsec != 0) { puts ("symlink atim not reset to zero"); status = 1; } if (st2.st_mtim.tv_sec != 0 || st2.st_mtim.tv_nsec != 0) { puts ("symlink mtim not reset to zero"); status = 1; } if (status != 0) goto out; t[0].tv_sec = 1; t[0].tv_nsec = 0; t[1].tv_sec = 1; t[1].tv_nsec = 0; if (syscall(__NR_utimensat, fd, NULL, t, 0) != 0) error (1, errno, "utimensat failed"); if (fstat64 (fd, &st2) != 0) error (1, errno, "fstat failed"); if (st2.st_atim.tv_sec != 1 || st2.st_atim.tv_nsec != 0) { puts ("atim not reset to one"); status = 1; } if (st2.st_mtim.tv_sec != 1 || st2.st_mtim.tv_nsec != 0) { puts ("mtim not reset to one"); status = 1; } if (status == 0) puts ("all OK"); out: close (fd); unlink ("ttt"); unlink ("tttsym"); return status; } [akpm@linux-foundation.org: add missing i386 syscall table entry] Signed-off-by: Ulrich Drepper <drepper@redhat.com> Cc: Alexey Dobriyan <adobriyan@openvz.org> Cc: Michael Kerrisk <mtk-manpages@gmx.net> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rcutorture: Remove redundant assignment to cur_ops in for loopJosh Triplett2007-05-08
| | | | | | | | | | | | The for loop in rcutorture_init uses the condition cur_ops = torture_ops[i], cur_ops but then makes the same assignment to cur_ops inside the loop. Remove the redundant assignment inside the loop, and remove now-unnecessary braces. Signed-off-by: Josh Triplett <josh@kernel.org> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rcutorture: style cleanup: avoid != NULL in boolean testsJosh Triplett2007-05-08
| | | | | | | Signed-off-by: Josh Triplett <josh@kernel.org> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rcutorture: Use ARRAY_SIZE macro when appropriateAhmed S. Darwish2007-05-08
| | | | | | | | | Use ARRAY_SIZE macro already defined in kernel.h Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: align rq to cacheline boundarySiddha, Suresh B2007-05-08
| | | | | | | | | | | | Align the per cpu runqueue to the cacheline boundary. This will minimize the number of cachelines touched during remote wakeup. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Ravikiran G Thirumalai <kiran@scalex86.org> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched: redundant reschedule when set_user_nice() boosts a prio of a task ↵Dmitry Adamushko2007-05-08
| | | | | | | | | | | | | | | | | | | from the "expired" array - Make TASK_PREEMPTS_CURR(task, rq) return "true" only if the task's prio is higher than the current's one and the task is in the "active" array. This ensures we don't make redundant resched_task() calls when the task is in the "expired" array (as may happen now in set_user_prio(), rt_mutex_setprio() and pull_task() ) ; - generalise conditions for a call to resched_task() in set_user_nice(), rt_mutex_setprio() and sched_setscheduler() Signed-off-by: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Con Kolivas <kernel@kolivas.org> 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>
* sched: optimize siblings status check logic in wake_idle()Siddha, Suresh B2007-05-08
| | | | | | | | | | | | | | | | When a logical cpu 'x' already has more than one process running, then most likely the siblings of that cpu 'x' must be busy. Otherwise the idle siblings would have likely(in most of the scenarios) picked up the extra load making the load on 'x' atmost one. Use this logic to eliminate the siblings status check and minimize the cache misses encountered on a heavily loaded system. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> 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>