1. 01 Oct, 2008 11 commits
  2. 06 Sep, 2008 1 commit
    • Lennert Buytenhek's avatar
      [ARM] 5241/1: provide ioremap_wc() · 1ad77a87
      Lennert Buytenhek authored
      This patch provides an ARM implementation of ioremap_wc().
      We use different page table attributes depending on which CPU we
      are running on:
      - Non-XScale ARMv5 and earlier systems: The ARMv5 ARM documents four
        possible mapping types (CB=00/01/10/11).  We can't use any of the
        cached memory types (CB=10/11), since that breaks coherency with
        peripheral devices.  Both CB=00 and CB=01 are suitable for _wc, and
        CB=01 (Uncached/Buffered) allows the hardware more freedom than
        CB=00, so we'll use that.
        (The ARMv5 ARM seems to suggest that CB=01 is allowed to delay stores
        but isn't allowed to merge them, but there is no other mapping type
        we can use that allows the hardware to delay and merge stores, so
        we'll go with CB=01.)
      - XScale v1/v2 (ARMv5): same as the ARMv5 case above, with the slight
        difference that on these platforms, CB=01 actually _does_ allow
        merging stores.  (If you want noncoalescing bufferable behavior
        on Xscale v1/v2, you need to use XCB=101.)
      - Xscale v3 (ARMv5) and ARMv6+: on these systems, we use TEXCB=00100
        mappings (Inner/Outer Uncacheable in xsc3 parlance, Uncached Normal
        in ARMv6 parlance).
        The ARMv6 ARM explicitly says that any accesses to Normal memory can
        be merged, which makes Normal memory more suitable for _wc mappings
        than Device or Strongly Ordered memory, as the latter two mapping
        types are guaranteed to maintain transaction number, size and order.
        We use the Uncached variety of Normal mappings for the same reason
        that we can't use C=1 mappings on ARMv5.
        The xsc3 Architecture Specification documents TEXCB=00100 as being
        Uncacheable and allowing coalescing of writes, which is also just
        what we need.
      Signed-off-by: default avatarLennert Buytenhek <buytenh@marvell.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
  3. 04 Sep, 2008 3 commits
  4. 03 Sep, 2008 1 commit
  5. 02 Sep, 2008 24 commits
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 · d26acd92
      Linus Torvalds authored
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
        ipsec: Fix deadlock in xfrm_state management.
        ipv: Re-enable IP when MTU > 68
        net/xfrm: Use an IS_ERR test rather than a NULL test
        ath9: Fix ath_rx_flush_tid() for IRQs disabled kernel warning message.
        ath9k: Incorrect key used when group and pairwise ciphers are different.
        rt2x00: Compiler warning unmasked by fix of BUILD_BUG_ON
        mac80211: Fix debugfs union misuse and pointer corruption
        wireless/libertas/if_cs.c: fix memory leaks
        orinoco: Multicast to the specified addresses
        iwlwifi: fix 64bit platform firmware loading
        iwlwifi: fix apm_stop (wrong bit polarity for FLAG_INIT_DONE)
        iwlwifi: workaround interrupt handling no some platforms
        iwlwifi: do not use GFP_DMA in iwl_tx_queue_init
        net/wireless/Kconfig: clarify the description for CONFIG_WIRELESS_EXT_SYSFS
        net: Unbreak userspace usage of linux/mroute.h
        pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()
        ipv6: When we droped a packet, we should return NET_RX_DROP instead of 0
    • Thomas Gleixner's avatar
      [x86] Fix TSC calibration issues · fbb16e24
      Thomas Gleixner authored
      Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
      An ancient laptop of mine started throwing errors from b43legacy when
      I started using 2.6.27 on it. This has been bisected to commit bfc0f594
      "x86: merge tsc calibration".
      The unification of the TSC code adopted mostly the 64bit code, which
      prefers PMTIMER/HPET over the PIT calibration.
      Larrys system has an AMD K6 CPU. Such systems are known to have
      PMTIMER incarnations which run at double speed. This results in a
      miscalibration of the TSC by factor 0.5. So the resulting calibrated
      CPU/TSC speed is half of the real CPU speed, which means that the TSC
      based delay loop will run half the time it should run. That might
      explain why the b43legacy driver went berserk.
      On the other hand we know about systems, where the PIT based
      calibration results in random crap due to heavy SMI/SMM
      disturbance. On those systems the PMTIMER/HPET based calibration logic
      with SMI detection shows better results.
      According to Alok also virtualized systems suffer from the PIT
      calibration method.
      The solution is to use a more wreckage aware aproach than the current
      either/or decision.
      1) reimplement the retry loop which was dropped from the 32bit code
      during the merge. It repeats the calibration and selects the lowest
      frequency value as this is probably the closest estimate to the real
      2) Monitor the delta of the TSC values in the delay loop which waits
      for the PIT counter to reach zero. If the maximum value is
      significantly different from the minimum, then we have a pretty safe
      indicator that the loop was disturbed by an SMI.
      3) keep the pmtimer/hpet reference as a backup solution for systems
      where the SMI disturbance is a permanent point of failure for PIT
      based calibration
      4) do the loop iteration for both methods, record the lowest value and
      decide after all iterations finished.
      5) Set a clear preference to PIT based calibration when the result
      makes sense.
      The implementation does the reference calibration based on
      HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
      but keeps separate TSC values to ensure the "independency" of the
      resulting calibration values.
      Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
      (affected machine with a double speed pmtimer which I grabbed out of
      the dump), Pentium class machines and AMD/Intel 64 bit boxen.
      Bisected-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Tested-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • David S. Miller's avatar
      ipsec: Fix deadlock in xfrm_state management. · 37b08e34
      David S. Miller authored
      Ever since commit 4c563f76
      ("[XFRM]: Speed up xfrm_policy and xfrm_state walking") it is
      illegal to call __xfrm_state_destroy (and thus xfrm_state_put())
      with xfrm_state_lock held.  If we do, we'll deadlock since we
      have the lock already and __xfrm_state_destroy() tries to take
      it again.
      Fix this by pushing the xfrm_state_put() calls after the lock
      is dropped.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    • Andrew Morton's avatar
      drivers/char/random.c: fix a race which can lead to a bogus BUG() · 8b76f46a
      Andrew Morton authored
      Fix a bug reported by and diagnosed by Aaron Straus.
      This is a regression intruduced into 2.6.26 by
          commit adc782da
          Author: Matt Mackall <mpm@selenic.com>
          Date:   Tue Apr 29 01:03:07 2008 -0700
              random: simplify and rename credit_entropy_store
      credit_entropy_bits() does:
      	spin_lock_irqsave(&r->lock, flags);
      	if (r->entropy_count > r->poolinfo->POOLBITS)
      		r->entropy_count = r->poolinfo->POOLBITS;
      so there is a time window in which this BUG_ON():
      static size_t account(struct entropy_store *r, size_t nbytes, int min,
      		      int reserved)
      	unsigned long flags;
      	BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);
      	/* Hold lock while accounting */
      	spin_lock_irqsave(&r->lock, flags);
      can trigger.
      We could fix this by moving the assertion inside the lock, but it seems
      safer and saner to revert to the old behaviour wherein
      entropy_store.entropy_count at no time exceeds
      Reported-by: default avatarAaron Straus <aaron@merfinllc.com>
      Cc: Matt Mackall <mpm@selenic.com>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: <stable@kernel.org>		[2.6.26.x]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • John Kacur's avatar
      pm_qos_requirement might sleep · 9d359357
      John Kacur authored
      Make PM_QOS and CPU_IDLE play nicer when run with the RT-Preempt kernel.
      The purpose of the patch is to remove the spin_lock around the read in the
      function pm_qos_requirement - since spinlocks can sleep in -rt and this
      function is called from idle.
      CPU_IDLE polls the target_value's of some of the pm_qos parameters from
      the idle loop causing sleeping locking warnings.  Changing the
      target_value to an atomic avoids this issue.
      Remove the spinlock in pm_qos_requirement by making target_value an atomic
      Signed-off-by: default avatarmark gross <mgross@linux.intel.com>
      Signed-off-by: default avatarJohn Kacur <jkacur@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Rafael J. Wysocki's avatar
      rtc-cmos: wake again from S5 · 74c4633d
      Rafael J. Wysocki authored
      Update rtc-cmos shutdown handling to leave RTC alarms active, resolving
       on several boards.  There
      are still some systems where the ACPI event handling doesn't cooperate.
      (Possibly related to bugid 11312, reporting the spontaneous disabling of
      RTC events.)
      Bug 11411 reported that changes to work around some ACPI event issues
      broke wake-from-S5 handling, as used for DVR applications.  (They like to
      power off, then wake later to record programs.)
      [yakui.zhao@intel.com: add shutdown for PNP devices]
      [dbrownell@users.sourceforge.net: update comments]
      Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      Signed-off-by: default avatarZhao Yakui <yakui.zhao@intel.com>
      Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
      Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
      Cc: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Russ Anderson's avatar
      sysfs: document files in /sys/firmware/sgi_uv/ · 8b3a8944
      Russ Anderson authored
      Document files in /sys/firmware/sgi_uv/.
      Signed-off-by: default avatarRuss Anderson <rja@sgi.com>
      Cc: Jack Steiner <steiner@sgi.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Acked-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Mike Christie's avatar
      ibft: fix target info parsing in ibft module · bb8fb4e6
      Mike Christie authored
      I got this patch through Red Hat's bugzilla from the bug submitter and
      patch creator.  I have just fixed it up so it applies without fuzz to
      upstream kernels.
      Original patch and description from Shyam kumar Iyer:
      The issue [ibft module not displaying targets with short names] is because
      of an offset calculatation error in the iscsi_ibft.c code.  Due to this
      error directory structure for the target in /sys/firmware/ibft does not
      get created and so the initiator is unable to connect to the target.
      Note that this bug surfaced only with an name that had a short section at
      the end.  eg: "iqn.1984-05.com.dell:dell".  It did not surface when the
      iqn's had a longer section at the end.  eg:
      So, the eot_offset was calculated such that an extra 48 bytes i.e.  the
      size of the ibft_header which has already been accounted was subtracted
      This was not evident with longer iqn names because they would overshoot
      the total ibft length more than 48 bytes and thus would escape the bug.
      Signed-off-by: default avatarShyam Kumar Iyer <shyam_iyer@dell.com>
      Signed-off-by: default avatarMike Christie <michaelc@cs.wisc.edu>
      Cc: Konrad Rzeszutek <konrad@virtualiron.com>
      Cc: Peter Jones <pjones@redhat.com>
      Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Jan Altenberg's avatar
      rtc_time_to_tm: fix signed/unsigned arithmetic · 73442daf
      Jan Altenberg authored
      commit 945185a6
       ("rtc: rtc_time_to_tm: use
      unsigned arithmetic") changed the some types in rtc_time_to_tm() to
       void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
      -       register int days, month, year;
      +       unsigned int days, month, year;
      This doesn't work for all cases, because days is checked for < 0 later
      if (days < 0) {
      	year -= 1;
      	days += 365 + LEAP_YEAR(year);
      I think the correct fix would be to keep days signed and do an appropriate
      cast later on.
      Signed-off-by: default avatarJan Altenberg <jan.altenberg@linutronix.de>
      Cc: Maciej W. Rozycki <macro@linux-mips.org>
      Cc: Alessandro Zummo <a.zummo@towertech.it>
      Cc: David Brownell <david-b@pacbell.net>
      Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
      Cc: <stable@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Krzysztof Helt's avatar
      tdfxfb: fix frame buffer name overrun · b4a49b12
      Krzysztof Helt authored
      If there are more then one graphics card handled by the tdfxfb driver the
      name of the frame buffer overruns reserved size.
      Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@wp.pl>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Krzysztof Helt's avatar
      tdfxfb: fix SDRAM memory size detection · bf6910c0
      Krzysztof Helt authored
      Fix memory detection on Voodoo3 cards with SDRAM memory.
      Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@wp.pl>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Matthew Garrett's avatar
      hp-wmi: add proper hotkey support · a8823aef
      Matthew Garrett authored
      It turns out that event 0x4 merely indcates that a hotkey has been
      pressed, not which one.  A further query is required in order to determine
      the actual keypress.  The following patch adds support for that along with
      the known keycodes.
      Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Matthew Garrett's avatar
      hp-wmi: update to match current rfkill semantics · 3f6e2f13
      Matthew Garrett authored
      hp-wmi currently changes the RFKill state by altering the struct members
      rather than using the dedicated interface, meaning that update events
      won't be pushed to userspace.  This patch fixes that, along with fixing
      the declared type of the WWAN kill switch.  It also ensures that rfkill
      interfaces are only registered for hardware that exists.
      Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
      Acked-by: default avatarHenrique de Moraes Holschuh <hmh@hmh.eng.br>
      Cc: Ivo van Doorn <ivdoorn@gmail.com>
      Cc: Dave Young <hidave.darkstar@gmail.com>
      Cc: Marcel Holtmann <marcel@holtmann.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Nadia Derbey's avatar
      ipc: document the new auto_msgmni proc file · 61e55d05
      Nadia Derbey authored
      Update Documentation/filesystems/proc.txt: it describes the file
      auto_msgmni intoduced to enable/disable msgmni automatic recomputing upon
      memory add/remove (see thread http://lkml.org/lkml/2008/7/4/27
      ).  Also
      added a description for msgmni (this filex is only listed in
      Signed-off-by: default avatarNadia Derbey <Nadia.Derbey@bull.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • KOSAKI Motohiro's avatar
      mm: size of quicklists shouldn't be proportional to the number of CPUs · b9541852
      KOSAKI Motohiro authored
      Quicklists store pages for each CPU as caches.  (Each CPU can cache
      node_free_pages/16 pages)
      It is used for page table cache.  exit() will increase the cache size,
      while fork() consumes it.
      So for example if an apache-style application runs (one parent and many
      child model), one CPU process will fork() while another CPU will process
      the middleware work and exit().
      At that time, the CPU on which the parent runs doesn't have page table
      cache at all.  Others (on which children runs) have maximum caches.
      	QList_max = (#ofCPUs - 1) x Free / 16
      	=> QList_max / (Free + QList_max) = (#ofCPUs - 1) / (16 + #ofCPUs - 1)
      So, How much quicklist memory is used in the maximum case?
      This is proposional to # of CPUs because the limit of per cpu quicklist
      cache doesn't see the number of cpus.
      Above calculation mean
      	 Number of CPUs per node            2    4    8   16
      	 ==============================  ====================
      	 QList_max / (Free + QList_max)   5.8%  16%  30%  48%
      Wow! Quicklist can spend about 50% memory at worst case.
      My demonstration program is here
      #define _GNU_SOURCE
      #include <stdio.h>
      #include <errno.h>
      #include <stdlib.h>
      #include <string.h>
      #include <sched.h>
      #include <unistd.h>
      #include <sys/mman.h>
      #include <sys/wait.h>
      #define BUFFSIZE 512
      int max_cpu(void)	/* get max number of logical cpus from /proc/cpuinfo */
        FILE *fd;
        char *ret, buffer[BUFFSIZE];
        int cpu = 1;
        fd = fopen("/proc/cpuinfo", "r");
        if (fd == NULL) {
        while (1) {
          ret = fgets(buffer, BUFFSIZE, fd);
          if (ret == NULL)
          if (!strncmp(buffer, "processor", 9))
            cpu = atoi(strchr(buffer, ':') + 2);
        return cpu;
      void cpu_bind(int cpu)	/* bind current process to one cpu */
        cpu_set_t mask;
        int ret;
        CPU_SET(cpu, &mask);
        ret = sched_setaffinity(0, sizeof(mask), &mask);
        if (ret == -1) {
        sched_yield();	/* not necessary */
      #define MMAP_SIZE (10 * 1024 * 1024)	/* 10 MB */
      #define FORK_INTERVAL 1	/* 1 second */
      main(int argc, char *argv[])
        int cpu_max, nextcpu;
        long pagesize;
        pid_t pid;
        /* set max number of logical cpu */
        if (argc > 1)
          cpu_max = atoi(argv[1]) - 1;
          cpu_max = max_cpu();
        /* get the page size */
        pagesize = sysconf(_SC_PAGESIZE);
        if (pagesize == -1) {
        /* prepare parent process */
        nextcpu = cpu_max;
        /* select destination cpu for child process by round-robin rule */
        if (++nextcpu > cpu_max)
          nextcpu = 1;
        pid = fork();
        if (pid == 0) { /* child action */
          char *p;
          int i;
          /* consume page tables */
          p = mmap(0, MMAP_SIZE, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
          i = MMAP_SIZE / pagesize;
          while (i-- > 0) {
            *p = 1;
            p += pagesize;
          /* move to other cpu */
          printf("a child moved to cpu%d after mmap().\n", nextcpu);
          /* back page tables to pgtable_quicklist */
        } else if (pid > 0) { /* parent action */
          waitpid(pid, NULL, WNOHANG);
        goto loop;
      When above program which does task migration runs, my 8GB box spends
      800MB of memory for quicklist.  This is not memory leak but doesn't seem
      % cat /proc/meminfo
      MemTotal:        7701568 kB
      MemFree:         4724672 kB
      Quicklists:       844800 kB
      - My machine spec is
      	number of numa node: 2
      	number of cpus:      8 (4CPU x2 node)
              total mem:           8GB (4GB x2 node)
              free mem:            about 5GB
      - Then, 4.7GB x 16% ~= 880MB.
        So, Quicklist can use 800MB.
      So, if following spec machine run that program
         CPUs: 64 (8cpu x 8node)
         Mem:  1TB (128GB x8node)
      Then, quicklist can waste 300GB (= 1TB x 30%).  It is too large.
      So, I don't like cache policies which is proportional to # of cpus.
      My patch changes the number of caches
         per-cpu-cache-amount = memory_on_node / 16
         per-cpu-cache-amount = memory_on_node / 16 / number_of_cpus_on_node.
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
      Acked-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Tested-by: default avatarDavid Miller <davem@davemloft.net>
      Acked-by: default avatarMike Travis <travis@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • KOSAKI Motohiro's avatar
      mm: show quicklist usage in /proc/meminfo · 4b856152
      KOSAKI Motohiro authored
      Quicklists can consume several GB of memory.  We should provide a means of
      monitoring this.
      After this patch is applied, /proc/meminfo will output the following:
      % cat /proc/meminfo
      MemTotal:      7715392 kB
      MemFree:       5401600 kB
      Buffers:         80384 kB
      Cached:         300800 kB
      SwapCached:          0 kB
      Active:         235584 kB
      Inactive:       262656 kB
      SwapTotal:     2031488 kB
      SwapFree:      2031488 kB
      Dirty:            3520 kB
      Writeback:           0 kB
      AnonPages:      117696 kB
      Mapped:          38528 kB
      Slab:          1589952 kB
      SReclaimable:    23104 kB
      SUnreclaim:    1566848 kB
      PageTables:      14656 kB
      NFS_Unstable:        0 kB
      Bounce:              0 kB
      WritebackTmp:        0 kB
      CommitLimit:   5889152 kB
      Committed_AS:   393152 kB
      VmallocTotal: 17592177655808 kB
      VmallocUsed:     29056 kB
      VmallocChunk: 17592177626432 kB
      Quicklists:     130944 kB
      HugePages_Total:     0
      HugePages_Free:      0
      HugePages_Rsvd:      0
      HugePages_Surp:      0
      Hugepagesize:    262144 kB
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Li Zefan's avatar
      devcgroup: fix race against rmdir() · 36fd71d2
      Li Zefan authored
      During the use of a dev_cgroup, we should guarantee the corresponding
      cgroup won't be deleted (i.e.  via rmdir).  This can be done through
      css_get(&dev_cgroup->css), but here we can just get and use the dev_cgroup
      under rcu_read_lock.
      And also remove checking NULL dev_cgroup, it won't be NULL since a task
      always belongs to a cgroup.
      Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Cc: Paul Menage <menage@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Krzysztof Helt's avatar
      cirrusfb: check_par fixes · 09a2910e
      Krzysztof Helt authored
      1. Check if virtual resolution fits into memory.
         Otherwise, Linux hangs during panning.
      2. When selected use all available memory to
          maximize yres_virtual to speed up panning
         (previously also xres_virtual was increased).
      3. Simplify memory restriction calculations.
      Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@poczta.fm>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Oleg Nesterov's avatar
      pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits · 950bbabb
      Oleg Nesterov authored
      We don't change pid_ns->child_reaper when the main thread of the
      subnamespace init exits.  As Robert Rex <robert.rex@exasol.com> pointed
      out this is wrong.
      Yes, the re-parenting itself works correctly, but if the reparented task
      exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the
      main thread is zombie its ->nsproxy was already cleared by
      Introduce the new function, find_new_reaper(), which finds the new
      ->parent for the re-parenting and changes ->child_reaper if needed.  Kill
      the now unneeded exit_child_reaper().
      Also move the changing of ->child_reaper from zap_pid_ns_processes() to
      find_new_reaper(), this consolidates the games with ->child_reaper and
      makes it stable under tasklist_lock.
      Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391
      Reported-by: default avatarRobert Rex <robert.rex@exasol.com>
      Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
      Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Acked-by: default avatarPavel Emelyanov <xemul@openvz.org>
      Acked-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Oleg Nesterov's avatar
      pid_ns: zap_pid_ns_processes: fix the ->child_reaper changing · add0d4df
      Oleg Nesterov authored
      zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong.
      Yes, we have already killed all tasks in this namespace, and sys_wait4()
      doesn't see any child.  But this doesn't mean ->children list is empty, we
      may have EXIT_DEAD tasks which are not visible to do_wait().  In that case
      the subsequent forget_original_parent() will crash the kernel because it
      will try to re-parent these tasks to the NULL reaper.
      Even if there are no childs, it is not good that forget_original_parent()
      uses reaper == NULL.
      Change the code to set ->child_reaper = init_pid_ns.child_reaper instead.
      We could use pid_ns->parent->child_reaper as well, I think this does not
      really matter.  These EXIT_DEAD tasks are not visible to the new ->parent
      after re-parenting, they will silently do release_task() eventually.
      Note that we must change ->child_reaper, otherwise
      forget_original_parent() will use reaper == father, and in that case we
      will hit the (correct) BUG_ON(!list_empty(&father->children)).
      Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
      Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Acked-by: default avatarSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
      Acked-by: default avatarPavel Emelyanov <xemul@openvz.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • David Brownell's avatar
      mmc: at91_mci: don't use coherent dma buffers · e385ea63
      David Brownell authored
      At91_mci is abusing dma_free_coherent(), which may not be called with IRQs
      disabled.  I saw "mkfs.ext3" on an MMC card objecting voluminously as each
      write completed:
       WARNING: at arch/arm/mm/consistent.c:368 dma_free_coherent+0x2c/0x224()
       [<c002726c>] (dump_stack+0x0/0x14) from [<c00387d4>] (warn_on_slowpath+0x4c/0x68)
       [<c0038788>] (warn_on_slowpath+0x0/0x68) from [<c0028768>] (dma_free_coherent+0x2c/0x224)
        r6:00008008 r5:ffc06000 r4:00000000
       [<c002873c>] (dma_free_coherent+0x0/0x224) from [<c01918ac>] (at91_mci_irq+0x374/0x420)
       [<c0191538>] (at91_mci_irq+0x0/0x420) from [<c0065d9c>] (handle_IRQ_event+0x2c/0x6c)
      This bug has been around for a LONG time.  The MM warning is from late
      2005, but the driver merged a year later ...  so I'm puzzled why nobody
      noticed this before now.
      The fix involves noting that this buffer shouldn't be DMA-coherent; it's
      just used for normal DMA writes.  So replace it with standard kmalloc()
      buffering and DMA mapping calls.
      This is the quickie fix.  A better one would not rely on allocating large
      bounce buffers.  (Note that dma_alloc_coherent could have failed too, but
      that case was ignored...  kmalloc is a bit more likely to fail though.)
      Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
      Acked-by: default avatarPierre Ossman <drzeus-mmc@drzeus.cx>
      Cc: Andrew Victor <linux@maxim.org.za>
      Acked-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Will Newton's avatar
      8250: improve workaround for UARTs that don't re-assert THRE correctly · 363f66fe
      Will Newton authored
      Recent changes to tighten the check for UARTs that don't correctly
      re-assert THRE (01c194d9
      : "serial 8250:
      tighten test for using backup timer") caused problems when such a UART was
      opened for the second time - the bug could only successfully be detected
      at first initialization.  For users of this version of this particular
      UART IP it is fatal.
      This patch stores the information about the bug in the bugs field of the
      port structure when the port is first started up so subsequent opens can
      check this bit even if the test for the bug fails.
      David Brownell: "My own exposure to this is that the UART on DaVinci
      hardware, which TI allegedly derived from its original 16550 logic, has
      periodically gone from working to unusable with the mainline 8250.c ...
      and back and forth a bunch.  Currently it's "unusable", a regression from
      some previous versions.  With this patch from Will, it's usable."
      Signed-off-by: default avatarWill Newton <will.newton@gmail.com>
      Acked-by: default avatarAlex Williamson <alex.williamson@hp.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: David Brownell <david-b@pacbell.net>
      Cc: <stable@kernel.org>		[2.6.26.x]
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Henrik Rydberg's avatar
      MAINTAINERS: add a maintainer for the BCM5974 multitouch driver · bd7aa4b2
      Henrik Rydberg authored
      Signed-off-by: default avatarHenrik Rydberg <rydberg@euromail.se>
      Cc: Dmitry Torokhov <dtor@mail.ru>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    • Marcin Slusarz's avatar
      mm/bootmem: silence section mismatch warning - contig_page_data/bootmem_node_data · 52765583
      Marcin Slusarz authored
      WARNING: vmlinux.o(.data+0x1f5c0): Section mismatch in reference from the variable contig_page_data to the variable .init.data:bootmem_node_data
      The variable contig_page_data references
      the variable __initdata bootmem_node_data
      If the reference is valid then annotate the
      variable with __init* (see linux/init.h) or name the variable:
      *driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
      Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
      Cc: Johannes Weiner <hannes@saeurebad.de>
      Cc: Sean MacLennan <smaclennan@pikatech.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>