[RFC][PATCH 4/12] x86: introduce copy_in_user() for 32-bit
During the work of KVM's dirty page logging optimization, we encountered the need of copy_in_user() for 32-bit x86 and ppc: these will be used for manipulating dirty bitmaps in user space. So we implement copy_in_user() for 32-bit with existing generic copy user helpers. Signed-off-by: Takuya Yoshikawa <yoshik... 4 May 2010 10:05
[RFC][PATCH 7/12 not tested yet] PPC: introduce __set_bit() like function for bitmaps in user space
During the work of KVM's dirty page logging optimization, we encountered the need of manipulating bitmaps in user space efficiantly. To achive this, we introduce a uaccess function for setting a bit in user space following Avi's suggestion. KVM is now using dirty bitmaps for live-migration and VGA. Although we ... 4 May 2010 10:05
KEYS: Use RCU dereference wrappers in keyring key type code
Serge E. Hallyn <serue(a)us.ibm.com> wrote: <shrug> does this mean that the klist = rcu_dereference_check(keyring->payload.subscriptions, lockdep_is_held(&key_serial_lock)); in security/keys/gc.c:key_gc_keyring() should become a rcu_dereference_protected() to avoid the rcu_dereference_r... 4 May 2010 10:05
[RFC][PATCH 1/12 applied today] KVM: x86: avoid unnecessary bitmap allocation when memslot is clean
Although we always allocate a new dirty bitmap in x86's get_dirty_log(), it is only used as a zero-source of copy_to_user() and freed right after that when memslot is clean. This patch uses clear_user() instead of doing this unnecessary zero-source allocation. Performance improvement: as we can expect easily, the... 4 May 2010 10:05
[2.6.32] task hung
Hi, I'm copying 6GB of data onto an NBD device using a simple tool which differs from dd/cat in that it measures how long it takes to write each block and does a sync after each block. Now during that run I get: [45480.665074] INFO: task measurecopy:13780 blocked for more than 120 seconds. [45480.665086] "ech... 4 May 2010 10:05
[RFC PATCHSET] sched,perf: unify tracers in sched and move perf on top of TP
Hello, all. This patchset does the following two things. * 0001-0007: Unify the three tracers (tracepoints, perf_events and preempt/sched notifiers) in scheduler. * 0008-0012: Move perf hooks in sched on top of tracepoints if TPs are enabled. It probably should be two separate patchsets with the f... 4 May 2010 08:59
[PATCH 08/12] sched: add switch_in and tick tracepoints
Define and add sched_switch_in and sched_tick tracepoints. Both are colocated with perf event functions. These will be used to make perf use tracepoints. Signed-off-by: Tejun Heo <tj(a)kernel.org> --- include/trace/events/sched.h | 14 ++++++++++++++ kernel/sched.c | 4 ++-- 2 files changed... 4 May 2010 08:59
[PATCH 09/12] perf: factor out perf_event_switch_clones()
Factor out perf_event_switch_clones() from perf_event_task_sched_out(). This is to ease future changes and doesn't cause any functional difference. Signed-off-by: Tejun Heo <tj(a)kernel.org> Cc: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Cc: Paul Mackerras <paulus(a)samba.org> Cc: Ingo Molnar <mingo(a)elte.hu> Cc: Arn... 4 May 2010 08:59
[PATCH 01/12] sched: drop @cpu argument from sched_in preempt notifier
@cpu parameter is superflous. Drop it. This will help unifying notifiers in sched. Signed-off-by: Tejun Heo <tj(a)kernel.org> Cc: Avi Kivity <avi(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Mike Galbraith <efault(a)gmx.de> Cc: Ingo Molnar <mingo(a)elte.hu> --- include/linux/preempt.h | 3 +-- k... 4 May 2010 08:59
[PATCH 05/12] perf: move perf_event_task_sched_in() next to fire_sched_notifiers_in()
Move perf_event_task_sched_in() after finish_lock_switch() right before fire_sched_notifiers_in(). This costs an extra pair of irq enable/disable when switching in a perf task context but allows unifying event functions in a more flexible position (irq enabled, rq lock released). Signed-off-by: Tejun Heo <tj(a)ke... 4 May 2010 08:59