linux/init, branch v3.1.1

bootup: move 'usermodehelper_enable()' a little earlier

2011-09-30T02:21:01Z

Commit d5767c53535a ("bootup: move 'usermodehelper_enable()' to the end of do_basic_setup()") moved 'usermodehelper_enable()' to end of do_basic_setup() to after the initcalls. But then I get failed to let uvesafb work on my computer, and lose the splash boot. So maybe we could start usermodehelper_enable a little early to make some task work that need eary init with the help of user mode. [ I would *really* prefer that initcalls not call into user space - even the real 'init' hasn't been execve'd yet, after all! But for uvesafb it really does look like we don't have much choice. I considered doing this when we mount the root filesystem, but depending on config options that is in multiple places. We could do the usermode helper enable as a rootfs_initcall().. So I'm just using wang yanqing's trivial patch. It's not wonderful, but it's simple and should work. We should revisit this some day, though. - Linus ] Signed-off-by: Linus Torvalds

bootup: move 'usermodehelper_enable()' to the end of do_basic_setup()

2011-09-28T17:23:44Z

Doing it just before starting to call into cpu_idle() made a sick kind of sense only because the original bug we fixed (see commit 288d5abec831: "Boot up with usermodehelper disabled") was about problems with some scheduler data structures not being initialized, and they had better be initialized at that point. But it really didn't make any other conceptual sense, and doing it after the initial "schedule()" call for the idle thread actually opened up a race: what if the main initialization thread did everything without needing to sleep, and got all the way into user land too? Without actually having scheduled back to the idle thread? Now, in normal circumstances that doesn't ever happen, but it looks like Richard Cochran triggered exactly that on his ARM IXP4xx machines: "I have some ARM IXP4xx based machines that use the two on chip MAC ports (aka NPEs). The NPE needs a firmware in order to function. Ever since the following commit [that 288d5abec831 one], it is no longer possible to bring up the interfaces during the init scripts." with a call trace showing an ioctl coming from user space. Richard says: "The init is busybox, and the startup script does mount, syslogd, and then ifup, so that all can go by quickly." The fix is to move the usermodehelper_enable() into the main 'init' thread, and just put it after we've done all our initcalls. By then, everything really should be up, but we've obviously not actually started the user-mode portion of init yet. Reported-and-tested-by: Richard Cochran Signed-off-by: Linus Torvalds

init: carefully handle loglevel option on kernel cmdline.

2011-09-21T20:18:52Z

When a malformed loglevel value (for example "${abc}") is passed on the kernel cmdline, the loglevel itself is being set to 0. That then suppresses all following messages, including all the errors and crashes caused by other malformed cmdline options. This could make debugging process quite tricky. This patch leaves the previous value of loglevel if the new value is incorrect and reports an error code in this case. Signed-off-by: Alexander Sverdlin Signed-off-by: Linus Torvalds

Boot up with usermodehelper disabled

2011-08-04T08:03:29Z

The core device layer sends tons of uevent notifications for each device it finds, and if the kernel has been built with a non-empty CONFIG_UEVENT_HELPER_PATH that will make us try to execute the usermode helper binary for all these events very early in the boot. Not only won't the root filesystem even be mounted at that point, we literally won't have necessarily even initialized all the process handling data structures at that point, which causes no end of silly problems even when the usermode helper doesn't actually succeed in executing. So just use our existing infrastructure to disable the usermodehelpers to make the kernel start out with them disabled. We enable them when we've at least initialized stuff a bit. Problems related to an uninitialized init_ipc_ns.ids[IPC_SHM_IDS].rw_mutex reported by various people. Reported-by: Manuel Lauss Reported-by: Richard Weinberger Reported-by: Marc Zyngier Acked-by: Kay Sievers Cc: Andrew Morton Cc: Vasiliy Kulikov Cc: Greg KH Signed-off-by: Linus Torvalds

tmpfs: miscellaneous trivial cleanups

2011-08-04T00:25:23Z

While it's at its least, make a number of boring nitpicky cleanups to shmem.c, mostly for consistency of variable naming. Things like "swap" instead of "entry", "pgoff_t index" instead of "unsigned long idx". And since everything else here is prefixed "shmem_", better change init_tmpfs() to shmem_init(). Signed-off-by: Hugh Dickins Acked-by: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

init: skip calibration delay if previously done

2011-07-26T03:57:17Z

For each CPU, do the calibration delay only once. For subsequent calls, use the cached per-CPU value of loops_per_jiffy. This saves about 200ms of resume time on dual core Intel Atom N5xx based systems. This helps bring down the kernel resume time on such systems from about 500ms to about 300ms. [akpm@linux-foundation.org: make cpu_loops_per_jiffy static] [akpm@linux-foundation.org: clean up message text] [akpm@linux-foundation.org: fix things up after upstream rmk changes] Signed-off-by: Sameer Nanda Cc: Phil Carmody Cc: Andrew Worsley Cc: David Daney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: remove the leftovers of noswapaccount

2011-07-26T03:57:09Z

In commit a2c8990aed5ab ("memsw: remove noswapaccount kernel parameter"), Michal forgot to remove some left pieces of noswapaccount in the tree, this patch removes them all. Signed-off-by: WANG Cong Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branches 'x86-urgent-for-linus', 'core-debug-for-linus', 'irq-core-for-linus' and 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-07-23T17:33:08Z

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Make rwsem.S depend on CONFIG_RWSEM_XCHGADD_ALGORITHM * 'core-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: debug: Make CONFIG_EXPERT select CONFIG_DEBUG_KERNEL to unhide debug options * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: genirq: Remove unused CHECK_IRQ_PER_CPU() * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tools, x86: Fix 32-bit compile on 64-bit system

Merge branch 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-07-22T23:51:56Z

* 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mips: Fix i8253 clockevent fallout i8253: Cleanup outb/inb magic arm: Footbridge: Use common i8253 clockevent mips: Use common i8253 clockevent x86: Use common i8253 clockevent i8253: Create common clockevent implementation i8253: Export i8253_lock unconditionally pcpskr: MIPS: Make config dependencies finer grained pcspkr: Cleanup Kconfig dependencies i8253: Move remaining content and delete asm/i8253.h i8253: Consolidate definitions of PIT_LATCH x86: i8253: Consolidate definitions of global_clock_event i8253: Alpha, PowerPC: Remove unused asm/8253pit.h alpha: i8253: Cleanup remaining users of i8253pit.h i8253: Remove I8253_LOCK config i8253: Make pcsp sound driver use the shared i8253_lock i8253: Make pcspkr input driver use the shared i8253_lock i8253: Consolidate all kernel definitions of i8253_lock i8253: Unify all kernel declarations of i8253_lock i8253: Create linux/i8253.h and use it in all 8253 related files

Fix CPU spinlock lockups on secondary CPU bringup

2011-06-23T15:59:38Z

Secondary CPU bringup typically calls calibrate_delay() during its initialization. However, calibrate_delay() modifies a global variable (loops_per_jiffy) used for udelay() and __delay(). A side effect of 71c696b1 ("calibrate: extract fall-back calculation into own helper") introduced in the 2.6.39 merge window means that we end up with a substantial period where loops_per_jiffy is zero. This causes the spinlock debugging code to malfunction: u64 loops = loops_per_jiffy * HZ; for (;;) { for (i = 0; i < loops; i++) { if (arch_spin_trylock(&lock->raw_lock)) return; __delay(1); } ... } by never calling arch_spin_trylock() - resulting in the CPU locking up in an infinite loop inside __spin_lock_debug(). Work around this by only writing to loops_per_jiffy only once we have completed all the calibration decisions. Tested-by: Santosh Shilimkar Signed-off-by: Russell King Cc: (2.6.39-stable) -- Better solutions (such as omitting the calibration for secondary CPUs, or arranging for calibrate_delay() to return the LPJ value and leave it to the caller to decide where to store it) are a possibility, but would be much more invasive into each architecture. I think this is the best solution for -rc and stable, but it should be revisited for the next merge window. init/calibrate.c | 14 ++++++++------ 1 files changed, 8 insertions(+), 6 deletions(-) Signed-off-by: Linus Torvalds