- 08 May, 2007 40 commits
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Christoph Hellwig authored
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>
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Christoph Hellwig authored
Signed-off-by:
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Marko Vrh authored
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:
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David Brownell authored
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:
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Andrew Morton authored
David says "884b4aaa 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:
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David Brownell authored
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:
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David Brownell authored
Remove /proc/acpi/alarm file when the rtc-cmos "wakealarm" file is available. Instead, provide hooks that rtc-cmos will use. Signed-off-by:
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David Brownell authored
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: -
Yoichi Yuasa authored
- 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:
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Alessandro Zummo authored
Signed-off-by:
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David Brownell authored
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:
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David Brownell authored
Signed-off-by:
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David Brownell authored
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:
Greg Kroah-Hartman <gregkh@suse.de> Acked-By:
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David Brownell authored
Finish converting the RTC framework so it no longer uses class_device. Signed-off-by:
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David Brownell authored
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:
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David Brownell authored
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:
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David Brownell authored
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:
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David Brownell authored
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:
Adrian Bunk <bunk@stusta.de> Signed-off-by:
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Ulrich Drepper authored
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:
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Josh Triplett authored
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:
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Josh Triplett authored
Signed-off-by:
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Ahmed S. Darwish authored
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:
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Siddha, Suresh B authored
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:
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Dmitry Adamushko authored
- 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:
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Siddha, Suresh B authored
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:
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Eric Dumazet authored
I noticed expensive divides done in try_to_wakeup() and find_busiest_group() on a bi dual core Opteron machine (total of 4 cores), moderatly loaded (15.000 context switch per second) oprofile numbers : CPU: AMD64 processors, speed 2600.05 MHz (estimated) Counted CPU_CLK_UNHALTED events (Cycles outside of halt state) with a unit mask of 0x00 (No unit mask) count 50000 samples % symbol name ... 613914 1.0498 try_to_wake_up 834 0.0013 :ffffffff80227ae1: div %rcx 77513 0.1191 :ffffffff80227ae4: mov %rax,%r11 608893 1.0413 find_busiest_group 1841 0.0031 :ffffffff802260bf: div %rdi 140109 0.2394 :ffffffff802260c2: test %sil,%sil Some of these divides can use the reciprocal divides we introduced some time ago (currently used in slab AFAIK) We can assume a load will fit in a 32bits number, because with a SCHED_LOAD_SCALE=128 value, its still a theorical limit of 33554432 When/if we reach this limit one day, probably cpus will have a fast hardware divide and we can zap the reciprocal divide trick. Ingo suggested to rename cpu_power to __cpu_power to make clear it should not be modified without changing its reciprocal value too. I did not convert the divide in cpu_avg_load_per_task(), because tracking nr_running changes may be not worth it ? We could use a static table of 32 reciprocal values but it would add a conditional branch and table lookup. [akpm@linux-foundation.org: !SMP build fix] Signed-off-by:Eric Dumazet <dada1@cosmosbay.com> Acked-by:
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Siddha, Suresh B authored
Fix the process idle load balancing in the presence of dynticks. cpus for which ticks are stopped will sleep till the next event wakes it up. Potentially these sleeps can be for large durations and during which today, there is no periodic idle load balancing being done. This patch nominates an owner among the idle cpus, which does the idle load balancing on behalf of the other idle cpus. And once all the cpus are completely idle, then we can stop this idle load balancing too. Checks added in fast path are minimized. Whenever there are busy cpus in the system, there will be an owner(idle cpu) doing the system wide idle load balancing. Open items: 1. Intelligent owner selection (like an idle core in a busy package). 2. Merge with rcu's nohz_cpu_mask? Signed-off-by:
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Siddha, Suresh B authored
Periodic load balancing in recent kernels happen in the softirq. In certain -rt configurations, these softirqs are handled in softirqd context. And hence the check for idle processor was always returning busy (as nr_running > 1). This patch captures the idle information at the tick and passes this info to softirq context through an element 'idle_at_tick' in rq. [kernel@kolivas.org: Fix reverse idle at tick logic] Signed-off-by:
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Thomas Gleixner authored
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Thomas Gleixner <tglx@linutronix.de> Cc: Karsten Keil <kkeil@suse.de> Signed-off-by:
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Matthias Kaehlcke authored
The CAPI 2.0 interface uses a semaphore as mutex. Use the mutex API instead of the (binary) semaphore. Signed-off-by:
Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Cc: Karsten Keil <kkeil@suse.de> Signed-off-by:
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Mike Frysinger authored
the isdn_divertif contains kernel-only references so I've wrapped them in __KERNEL__ and add proper #include statements. Signed-off-by:
Mike Frysinger <vapier@gentoo.org> Cc: Karsten Keil <kkeil@suse.de> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by:
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Matthias Kaehlcke authored
Fix incorrect spinlock use in hysdn_log_close(). The function declared a spinlock on the stack and used it to 'protect' a shared driver structure. The patch simply removes the useless code. Signed-off-by:
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Armin Schindler authored
As pointed out by Robert P. J. Day, here is a patch to remove unused header files from Eicon/Dialogic ISDN driver. Signed-off-by:
Armin Schindler <armin@melware.de> Acked-by:
Karsten Keil <kkeil@suse.de> Signed-off-by:
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Adrian Bunk authored
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Jeff Layton authored
This patch makes it so that simple_fill_super and get_sb_pseudo assign their root inodes to be number 1. It also fixes up a couple of callers of simple_fill_super that were passing in files arrays that had an index at number 1, and adds a warning for any caller that sends in such an array. It would have been nice to have made it so that it wasn't possible to make such a collision, but some callers need to be able to control what inode number their entries get, so I think this is the best that can be done. Signed-off-by:
Jeff Layton <jlayton@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Jeff Layton authored
The problems are: - on filesystems w/o permanent inode numbers, i_ino values can be larger than 32 bits, which can cause problems for some 32 bit userspace programs on a 64 bit kernel. We can't do anything for filesystems that have actual >32-bit inode numbers, but on filesystems that generate i_ino values on the fly, we should try to have them fit in 32 bits. We could trivially fix this by making the static counters in new_inode and iunique 32 bits, but... - many filesystems call new_inode and assume that the i_ino values they are given are unique. They are not guaranteed to be so, since the static counter can wrap. This problem is exacerbated by the fix for #1. - after allocating a new inode, some filesystems call iunique to try to get a unique i_ino value, but they don't actually add their inodes to the hashtable, and so they're still not guaranteed to be unique if that counter wraps. This patch set takes the simpler approach of simply using iunique and hashing the inodes afterward. Christoph H. previously mentioned that he thought that this approach may slow down lookups for filesystems that currently hash their inodes. The questions are: 1) how much would this slow down lookups for these filesystems? 2) is it enough to justify adding more infrastructure to avoid it? What might be best is to start with this approach and then only move to using IDR or some other scheme if these extra inodes in the hashtable prove to be problematic. I've done some cursory testing with this patch and the overhead of hashing and unhashing the inodes with pipefs is pretty low -- just a few seconds of system time added on to the creation and destruction of 10 million pipes (very similar to the overhead that the IDR approach would add). The hard thing to measure is what effect this has on other filesystems. I'm open to ways to try and gauge this. Again, I've only converted pipefs as an example. If this approach is acceptable then I'll start work on patches to convert other filesystems. With a pretty-much-worst-case microbenchmark provided by Eric Dumazet <dada1@cosmosbay.com>: hashing patch (pipebench): sys 1m15.329s sys 1m16.249s sys 1m17.169s unpatched (pipebench): sys 1m9.836s sys 1m12.541s sys 1m14.153s Which works out to 1.05642174294555027017. So ~5-6% slowdown. This patch: When a 32-bit program that was not compiled with large file offsets does a stat and gets a st_ino value back that won't fit in the 32 bit field, glibc (correctly) generates an EOVERFLOW error. We can't do anything about fs's with larger permanent inode numbers, but when we generate them on the fly, we ought to try and have them fit within a 32 bit field. This patch takes the first step toward this by making the static counters in these two functions be 32 bits. [jlayton@redhat.com: mention that it's only the case for 32bit, non-LFS stat] Signed-off-by:
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Jan Nikitenko authored
Here is a driver for the Alchemy au1550 PSC (Programmable Serial Controller) in SPI master mode. It supports dma transfers using the Alchemy descriptor based dma controller for 4-8 bits per word SPI transfers. For 9-24 bits per word transfers, pio irq based mode is used to avoid setup of dma channels from scratch on each number of bits per word change. Tested with au1550; this may also work on other MIPS Alchemy cpus, like au1200/au1210/au1250. Used extensively with SD card connected via SPI; this handles 8.1MHz SPI clock transfers using dma without any problem (the highest SPI clock freq possible with au1550 running on 324MHz). The driver supports sharing of SPI bus by multiple devices. All features of Alchemy SPI mode are supported (all SPI modes, msb/lsb first, bits per word in 4-24 range). As the SPI clock of the controller depends on main input clock that shall be configured externally, platform data structure for au1550 SPI controller driver contains mainclk_hz attribute to define the input clock rate. From this value, dividers of the controller for SPI clock are set up for required frequency. Signed-off-by:
Jan Nikitenko <jan.nikitenko@gmail.com> Whitespace and section fixups. Remove partial workaround for platform setup bug in dma_mask setup; it couldn't work with multiple controllers. Signed-off-by:
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David Brownell authored
Various documentation updates for the SPI infrastructure, to clarify things that may not have been clear, to cope with lack of editing, and fix omissions. Also, plug SPI into the kernel-api DocBook template, and fix all the resulting glitches in document generation. Signed-off-by:
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Andrea Paterniani authored
Add a filesystem API for <linux/spi/spi.h> stack. The initial version of this interface is purely synchronous. dbrownell@users.sourceforge.net: Cleaned up, bugfixed; much simplified; added preliminary documentation. Works with mdev given CONFIG_SYSFS_DEPRECATED; and presumably udev. Updated SPI_IOC_MESSAGE ioctl to full spi_message semantics, supporting groups of one or more transfers (each of which may be full duplex if desired). This is marked as EXPERIMENTAL with an explicit disclaimer that the API (notably the ioctls) is subject to change. Signed-off-by:
Andrea Paterniani <a.paterniani@swapp-eng.it> Signed-off-by:
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David Brownell authored
Simplify the spi_butterfly driver by removing incomplete/unused support for the second SPI bus, implemented by the USI controller. This should make this a clearer example of how to write a parport bitbang driver. Signed-off-by:
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