Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 161
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 11 4月, 2012 3 次提交
    • M
      [S390] update default configuration · ac2ac6e8
      由 Michael Holzheu 提交于 
      Add TASKSTATS options, enable CRASH_DUMP, and regenerate defconfig
file with "make savedefconfig".
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      ac2ac6e8
    • M
      [S390] fix tlb flushing for page table pages · cd94154c
      由 Martin Schwidefsky 提交于 
      Git commit 36409f63 "use generic RCU
page-table freeing code" introduced a tlb flushing bug. Partially revert
the above git commit and go back to s390 specific page table flush code.

For s390 the TLB can contain three types of entries, "normal" TLB
page-table entries, TLB combined region-and-segment-table (CRST) entries
and real-space entries. Linux does not use real-space entries which
leaves normal TLB entries and CRST entries. The CRST entries are
intermediate steps in the page-table translation called translation paths.
For example a 4K page access in a three-level page table setup will
create two CRST TLB entries and one page-table TLB entry. The advantage
of that approach is that a page access next to the previous one can reuse
the CRST entries and needs just a single read from memory to create the
page-table TLB entry. The disadvantage is that the TLB flushing rules are
more complicated, before any page-table may be freed the TLB needs to be
flushed.

In short: the generic RCU page-table freeing code is incorrect for the
CRST entries, in particular the check for mm_users < 2 is troublesome.

This is applicable to 3.0+ kernels.

Cc: <stable@vger.kernel.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      cd94154c
    • M
      [S390] kernel: Use local_irq_save() for memcpy_real() · b785e0d0
      由 Michael Holzheu 提交于 
      Currently in the memcpy_real() function interrupts are disabled with
__arch_local_irq_stnsm(). In order to notify lockdep that interrupts
are disabled, with this patch local_irq_save() is used instead. The
function __arch_local_irq_stnsm() is still used for switching to
real mode.
Reviewed-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      b785e0d0
  3. 30 3月, 2012 1 次提交
  5. 29 3月, 2012 2 次提交
  7. 24 3月, 2012 1 次提交
    • J
      coredump: remove VM_ALWAYSDUMP flag · 909af768
      由 Jason Baron 提交于 
      The motivation for this patchset was that I was looking at a way for a
qemu-kvm process, to exclude the guest memory from its core dump, which
can be quite large.  There are already a number of filter flags in
/proc/<pid>/coredump_filter, however, these allow one to specify 'types'
of kernel memory, not specific address ranges (which is needed in this
case).

Since there are no more vma flags available, the first patch eliminates
the need for the 'VM_ALWAYSDUMP' flag.  The flag is used internally by
the kernel to mark vdso and vsyscall pages.  However, it is simple
enough to check if a vma covers a vdso or vsyscall page without the need
for this flag.

The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new
'VM_NODUMP' flag, which can be set by userspace using new madvise flags:
'MADV_DONTDUMP', and unset via 'MADV_DODUMP'.  The core dump filters
continue to work the same as before unless 'MADV_DONTDUMP' is set on the
region.

The qemu code which implements this features is at:

  http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch

In my testing the qemu core dump shrunk from 383MB -> 13MB with this
patch.

I also believe that the 'MADV_DONTDUMP' flag might be useful for
security sensitive apps, which might want to select which areas are
dumped.

This patch:

The VM_ALWAYSDUMP flag is currently used by the coredump code to
indicate that a vma is part of a vsyscall or vdso section.  However, we
can determine if a vma is in one these sections by checking it against
the gate_vma and checking for a non-NULL return value from
arch_vma_name().  Thus, freeing a valuable vma bit.
Signed-off-by: NJason Baron <jbaron@redhat.com>
Acked-by: NRoland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      909af768
  9. 23 3月, 2012 4 次提交
  11. 21 3月, 2012 1 次提交
  13. 16 3月, 2012 1 次提交
    • C
      [PATCH v3] ipc: provide generic compat versions of IPC syscalls · 48b25c43
      由 Chris Metcalf 提交于 
      When using the "compat" APIs, architectures will generally want to
be able to make direct syscalls to msgsnd(), shmctl(), etc., and
in the kernel we would want them to be handled directly by
compat_sys_xxx() functions, as is true for other compat syscalls.

However, for historical reasons, several of the existing compat IPC
syscalls do not do this.  semctl() expects a pointer to the fourth
argument, instead of the fourth argument itself.  msgsnd(), msgrcv()
and shmat() expect arguments in different order.

This change adds an ARCH_WANT_OLD_COMPAT_IPC config option that can be
set to preserve this behavior for ports that use it (x86, sparc, powerpc,
s390, and mips).  No actual semantics are changed for those architectures,
and there is only a minimal amount of code refactoring in ipc/compat.c.

Newer architectures like tile (and perhaps future architectures such
as arm64 and unicore64) should not select this option, and thus can
avoid having any IPC-specific code at all in their architecture-specific
compat layer.  In the same vein, if this option is not selected, IPC_64
mode is assumed, since that's what the <asm-generic> headers expect.

The workaround code in "tile" for msgsnd() and msgrcv() is removed
with this change; it also fixes the bug that shmat() and semctl() were
not being properly handled.
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>
      48b25c43
  15. 13 3月, 2012 2 次提交
    • M
      [S390] kernel: Pass correct stack for smp_call_ipl_cpu() · c6da39f2
      由 Michael Holzheu 提交于 
      Currently pcpu_devices->panic_stack is passed to pcpu_delegate() in
smp_call_ipl_cpu(). This is wrong because pcpu_delegate() expects
the bottom (high address) of the stack and pcpu_devices->panic_stack
points to the top (low address). We now pass the bottom of the stack
which is pcpu_devices->panic_stack + PAGE_SIZE.
Signed-off-by: NMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      c6da39f2
    • P
      sched: Cleanup cpu_active madness · 5fbd036b
      由 Peter Zijlstra 提交于 
      Stepan found:

CPU0		CPUn

_cpu_up()
  __cpu_up()

		boostrap()
		  notify_cpu_starting()
		  set_cpu_online()
		  while (!cpu_active())
		    cpu_relax()

<PREEMPT-out>

smp_call_function(.wait=1)
  /* we find cpu_online() is true */
  arch_send_call_function_ipi_mask()

  /* wait-forever-more */

<PREEMPT-in>
		  local_irq_enable()

  cpu_notify(CPU_ONLINE)
    sched_cpu_active()
      set_cpu_active()

Now the purpose of cpu_active is mostly with bringing down a cpu, where
we mark it !active to avoid the load-balancer from moving tasks to it
while we tear down the cpu. This is required because we only update the
sched_domain tree after we brought the cpu-down. And this is needed so
that some tasks can still run while we bring it down, we just don't want
new tasks to appear.

On cpu-up however the sched_domain tree doesn't yet include the new cpu,
so its invisible to the load-balancer, regardless of the active state.
So instead of setting the active state after we boot the new cpu (and
consequently having to wait for it before enabling interrupts) set the
cpu active before we set it online and avoid the whole mess.
Reported-by: NStepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1323965362.18942.71.camel@twinsSigned-off-by: NIngo Molnar <mingo@elte.hu>
      5fbd036b
  17. 11 3月, 2012 12 次提交
  19. 08 3月, 2012 7 次提交
  21. 05 3月, 2012 6 次提交