ICAC 2014 Special Tracks Call for Papers
11th International Conference on Autonomic Computing
June 18-20, 2014 Philadelphia, PA
Co-held with the 2015 USENIX Federated Conferences Week (June 17-20, 2014)
Sponsored by USENIX, the Advanced
Hello Sir.
i want to develop a kernel module that will scan page cache and find the
pfn of those pages that have a same content in cache and in secondary
storage like physical disk, so please give me some idea how should i start
to develop kernel module
v5-v6:
- Change the optimized 2-task contending code to make it fairer at the
expense of a bit of performance.
- Add a patch to support unfair queue spinlock for Xen.
- Modify the PV qspinlock code to follow what was done in the PV
ticketlock.
- Add performance data for the unfair lock
This patch introduces a new generic queue spinlock implementation that
can serve as an alternative to the default ticket spinlock. Compared
with the ticket spinlock, this queue spinlock should be almost as fair
as the ticket spinlock. It has about the same speed in single-thread
and it can be much
This patch adds a KVM init function to activate the unfair queue
spinlock in a KVM guest when the PARAVIRT_UNFAIR_LOCKS kernel config
option is selected.
Signed-off-by: Waiman Long waiman.l...@hp.com
---
arch/x86/kernel/kvm.c | 17 +
1 files changed, 17 insertions(+), 0
A major problem with the queue spinlock patch is its performance at
low contention level (2-4 contending tasks) where it is slower than
the corresponding ticket spinlock code. The following table shows the
execution time (in ms) of a micro-benchmark where 5M iterations of
the lock/unlock cycles
This patch adds a XEN init function to activate the unfair queue
spinlock in a XEN guest when the PARAVIRT_UNFAIR_LOCKS kernel config
option is selected.
Signed-off-by: Waiman Long waiman.l...@hp.com
---
arch/x86/xen/setup.c | 19 +++
1 files changed, 19 insertions(+), 0
Locking is always an issue in a virtualized environment as the virtual
CPU that is waiting on a lock may get scheduled out and hence block
any progress in lock acquisition even when the lock has been freed.
One solution to this problem is to allow unfair lock in a
para-virtualized environment. In
For architectures that support atomic operations on smaller 8 or
16 bits data types. It is possible to simplify the code and produce
slightly better optimized code at the expense of smaller number of
supported CPUs.
The qspinlock code can support up to a maximum of 4M-1 CPUs. With
less than 16K
This patch renames the paravirt_ticketlocks_enabled static key to a
more generic paravirt_spinlocks_enabled name.
Signed-off-by: Waiman Long waiman.l...@hp.com
---
arch/x86/include/asm/spinlock.h |4 ++--
arch/x86/kernel/kvm.c|2 +-
This patch adds the necessary KVM specific code to allow XEN to support
the sleeping and CPU kicking operations needed by the queue spinlock PV
code.
Signed-off-by: Waiman Long waiman.l...@hp.com
---
arch/x86/xen/spinlock.c | 95 --
This patch adds para-virtualization support to the queue spinlock in
the same way as was done in the PV ticket lock code. In essence, the
lock waiters will spin for a specified number of times (QSPIN_THRESHOLD
= 2^14) and then halted itself. The queue head waiter will spins
2*QSPIN_THRESHOLD times
This patch adds the necessary KVM specific code to allow KVM to support
the sleeping and CPU kicking operations needed by the queue spinlock PV
code.
A KVM guest of 20 CPU cores was created to run the disk workload of
the AIM7 benchmark on both ext4 and xfs RAM disks at 3000 users on a
3.14-rc6
On 03/12/2014 02:54 PM, Waiman Long wrote:
+
+ /*
+* Now wait until the lock bit is cleared
+*/
+ while (smp_load_acquire(qlock-qlcode) _QSPINLOCK_LOCKED)
+ arch_mutex_cpu_relax();
+
+ /*
+
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