From: Chengming Zhou
The SLAB_MEM_SPREAD flag is already a no-op as of 6.8-rc1, remove
its usage so we can delete it from slab. No functional change.
Signed-off-by: Chengming Zhou
---
drivers/dax/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dax/super.c b
From: Chengming Zhou
The SLAB_MEM_SPREAD flag is already a no-op as of 6.8-rc1, remove
its usage so we can delete it from slab. No functional change.
Signed-off-by: Chengming Zhou
---
fs/tracefs/inode.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c
On 2024/2/28 00:29, Dave Jiang wrote:
>
>
> On 2/24/24 6:47 AM, chengming.z...@linux.dev wrote:
>> From: Chengming Zhou
>>
>> The SLAB_MEM_SPREAD flag is already a no-op as of 6.8-rc1, remove
>> its usage so we can delete it from slab. No functional change.
&
On 2023/10/17 21:56, wuqiang.matt wrote:
> objpool is a scalable implementation of high performance queue for
> object allocation and reclamation, such as kretprobe instances.
>
> With leveraging percpu ring-array to mitigate hot spots of memory
> contention, it delivers near-linear scalability fo
Hello Johannes,
在 2021/2/17 上午4:00, Johannes Weiner 写道:
> Hello Chengming,
>
> This patch looks useful to me. A couple of comments below:
>
> On Tue, Feb 09, 2021 at 03:14:13PM +0800, Chengming Zhou wrote:
>> The commit 36b238d57172 ("psi: Optimize switching tasks insid
code from Johannes.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
kernel/sched/psi.c | 35 +--
kernel/sched/stats.h | 28
2 files changed, 37 insertions(+), 26 deletions(-)
diff --git a/kernel/sched/psi.c b/kerne
from Johannes
too, and the detailed bench results can be seen from here:
https://lore.kernel.org/patchwork/patch/1378653/#1577607
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
include/linux/psi.h | 1 -
kernel/sched/core.c | 1 -
kernel/sched/psi.c
Hello Johannes,
在 2021/2/9 下午11:48, Johannes Weiner 写道:
> Hello Chengming,
>
> On Tue, Feb 09, 2021 at 03:10:33PM +0800, Chengming Zhou wrote:
>> When the current task in a cgroup is in_memstall, the corresponding groupc
>> on that cpu is in PSI_MEM_FULL state, so we can e
psi_task_switch()
optimization things and the clearer changelog.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
include/linux/psi.h | 1 -
kernel/sched/core.c | 1 -
kernel/sched/psi.c | 52
kernel/sched/stats.h | 9 -
4
Hello Johannes,
在 2021/2/11 上午4:37, Johannes Weiner 写道:
> On Wed, Feb 10, 2021 at 12:06:05PM +0800, Chengming Zhou wrote:
>> Move the reclaim detection from the timer tick to the task state
>> tracking machinery using the recently added ONCPU state. And we
>> also add m
在 2021/2/9 上午2:18, Johannes Weiner 写道:
> On Sun, Feb 07, 2021 at 03:24:02PM +0800, Chengming Zhou wrote:
>> The FULL state doesn't exist for the CPU resource at the system level,
>> but exist at the cgroup level, means all non-idle tasks in a cgroup are
>> delayed on t
Song
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
Acked-by: Johannes Weiner
---
include/linux/psi_types.h | 3 ++-
kernel/sched/psi.c| 14 +++---
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/linux/psi_types.h b/include/linux/psi_types.h
在 2021/2/9 上午12:45, Johannes Weiner 写道:
> On Sun, Feb 07, 2021 at 07:56:42PM +0800, Chengming Zhou wrote:
>> From: zhouchengming
>>
>> When the current task in a cgroup is in_memstall, the corresponding psi_group
>> is in PSI_MEM_FULL state
> This is correct.
>
When the current task in a cgroup is in_memstall, the corresponding groupc
on that cpu is in PSI_MEM_FULL state, so we can exploit that to remove the
redundant psi_task_tick from scheduler_tick to save this periodic cost.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
include
t and prev task in sleep case, that can save many psi_group_change
especially when most activity comes from one leaf cgroup.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
kernel/sched/psi.c | 27 +--
kernel/sched/stats.h | 17 +++--
2 fi
We shouldn't skip iocg when its abs_vdebt is not zero.
Fixes: 0b80f9866e6b ("iocost: protect iocg->abs_vdebt with
iocg->waitq.lock")
Signed-off-by: Chengming Zhou
---
block/blk-iocost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/blk-iocost.c
iocg usage_idx is the latest usage index, we should start from the
oldest usage index to show the consecutive NR_USAGE_SLOTS usages.
Signed-off-by: Chengming Zhou
---
tools/cgroup/iocost_monitor.py | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/cgroup
在 2020/7/29 上午1:26, Steven Rostedt 写道:
> On Wed, 29 Jul 2020 00:59:33 +0800
> Chengming Zhou wrote:
>
>
>>> i.e.
>>>
>>> # echo some_module_function > set_ftrace_filter
>>> # rmmod module_with_that_function
>>> # insmo
The last else branch of current code may have not io waited in iocg,
in which case we should not inc nr_shortages, or the device vrate
will speed up even this iocg is not shortage of vtime.
Signed-off-by: Chengming Zhou
---
block/blk-iocost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion
From: zhouchengming
When I run a simple "perf bench sched pipe" test in a cgroup on my
machine, the output of "watch -d -n 1 cpu.pressure" of this cgroup
will report some avg10 10%-20%.
It's strange because there is not any other process in the cgroup.
Then I found that cpu contention/wait percen
)) # all ancestors
psi_group_change(prev, .clear=common?TSK_RUNNING:TSK_RUNNING|TSK_ONCPU)
When a voluntary sleep switches to another task, we remove one call of
psi_group_change() for every common cgroup ancestor of the two tasks.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
Updat
nting out the psi_task_switch()
optimization things and the clearer changelog.
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
Updates since v1:
- Fold changes from Johannes that compare task psi_flags instead of
in_memstall in the psi_task_switch() optimization and move it out
o
From: Johannes Weiner
Move the unlikely branches out of line. This eliminates undesirable
jumps during wakeup and sleeps for workloads that aren't under any
sort of resource pressure.
Signed-off-by: Johannes Weiner
---
kernel/sched/psi.c | 14 +++---
1 file changed, 7 insertions(+), 7
Song
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
Acked-by: Johannes Weiner
---
include/linux/psi_types.h | 3 ++-
kernel/sched/psi.c| 14 +++---
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/linux/psi_types.h b/include/linux/psi_types.h
branches
out of line to eliminate undesirable jumps during wakeup and sleeps.
Patch 4 optimize the voluntary sleep switch by remove one call of
psi_group_change() for every common cgroup ancestor of the two tasks.
Chengming Zhou (3):
psi: Add PSI_CPU_FULL state
psi: Use ONCPU state tracking
在 2021/3/4 上午12:05, Peter Zijlstra 写道:
> On Wed, Mar 03, 2021 at 04:32:18PM +0100, Peter Zijlstra wrote:
>
>> Yes, I can do that. Thanks!
> Please double check the patches as found here:
>
>
> https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/log/?h=sched/core
>
> I've manually e
these counters maintained in psi subsystem,
so this patch sum them up and export in the cgroup.stat interface.
Signed-off-by: Chengming Zhou
---
Documentation/admin-guide/cgroup-v2.rst | 9 +++
include/linux/psi.h | 1 +
kernel/cgroup/cgroup.c
The FULL state doesn't exist for the CPU resource at the system level,
but exist at the cgroup level, means all non-idle tasks in a cgroup are
delayed on the CPU resource which used by others outside of the cgroup.
Co-developed-by: Muchun Song
Signed-off-by: Muchun Song
Signed-off-by: Chen
From: zhouchengming
When the current task in a cgroup is in_memstall, the corresponding psi_group
is in PSI_MEM_FULL state, so we can remove the redundant psi_task_tick
from scheduler_tick to save this periodic cost.
Signed-off-by: Chengming Zhou
---
include/linux/psi.h | 1 -
kernel/sched
dlock when warn condition met. If we can mark the
printk_deferred area when rq lock held using pintk_deferred_{enter, exit},
all console output in that area will be deferred.
Signed-off-by: Chengming Zhou
Signed-off-by: MuChun Song
---
include/linux/printk.h | 8
kernel/p
The WARN_ON/WARN_ON_ONCE with rq lock held in __schedule() should be
deferred by marking the PRINTK_DEFERRED_CONTEXT_MASK, or will cause
deadlock on rq lock in the printk path.
Signed-off-by: Chengming Zhou
Signed-off-by: Muchun Song
---
kernel/sched/core.c | 2 ++
1 file changed, 2 insertions
在 2020/9/28 下午3:32, Peter Zijlstra 写道:
> On Mon, Sep 28, 2020 at 12:11:30AM +0800, Chengming Zhou wrote:
>> The WARN_ON/WARN_ON_ONCE with rq lock held in __schedule() should be
>> deferred by marking the PRINTK_DEFERRED_CONTEXT_MASK, or will cause
>> deadlock on rq lock in
在 2020/9/28 下午5:01, Peter Zijlstra 写道:
> On Mon, Sep 28, 2020 at 04:54:53PM +0800, Chengming Zhou wrote:
>> 在 2020/9/28 下午3:32, Peter Zijlstra 写道:
>>> On Mon, Sep 28, 2020 at 12:11:30AM +0800, Chengming Zhou wrote:
>>>> The WARN_ON/WARN_ON_ONCE with rq lock
ilters to find
ftrace_ops references it.
Signed-off-by: Chengming Zhou
Signed-off-by: Muchun Song
---
kernel/trace/ftrace.c | 16 +---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index fca01a168ae5..00087dea0174 100644
We should clear module from hash of all ops on ftrace_ops_list when
module going, or the ops including these modules will be matched
wrongly by new module loaded later.
Signed-off-by: Chengming Zhou
Signed-off-by: Muchun Song
---
kernel/trace/ftrace.c | 22 --
1 file
在 2020/7/28 下午8:53, Steven Rostedt 写道:
On Tue, 28 Jul 2020 18:27:19 +0800
Chengming Zhou wrote:
We should clear module from hash of all ops on ftrace_ops_list when
module going, or the ops including these modules will be matched
wrongly by new module loaded later.
This is really up to the
在 2020/7/28 下午9:02, Steven Rostedt 写道:
> On Tue, 28 Jul 2020 18:27:20 +0800
> Chengming Zhou wrote:
>
>> When module loaded and enabled, we will use __ftrace_replace_code
>> for module if any ftrace_ops referenced it found. But we will get
>> wrong ft
has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.
Signed-off-by: Chengming Zhou
Signed-off-by: Muchun Song
---
kernel/trace/ftrace.c | 11 +++
1 file changed
, in which case
we can use trampoline as an optimization.
Signed-off-by: Chengming Zhou
Signed-off-by: Muchun Song
---
kernel/trace/ftrace.c | 8
1 file changed, 8 insertions(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a3d141f53c9e..8c1d9e3daa67 100644
--- a
: Chengming Zhou
Signed-off-by: Chengming Zhou
---
kernel/cgroup/cgroup-internal.h | 1 +
kernel/cgroup/cgroup-v1.c | 5 +++--
kernel/cgroup/cgroup.c | 3 +--
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h
在 2020/9/10 下午10:32, Tejun Heo 写道:
> On Thu, Sep 10, 2020 at 01:52:07PM +0800, Chengming Zhou wrote:
>> We found cgroupstats_build would return -EINVAL when using netlink
>> CGROUPSTATS_CMD_GET interface to get stats on cgroup v2. Fix it by
>> supporting cgroup v
在 2020/9/21 下午10:50, Tejun Heo 写道:
> Hello,
>
> On Tue, Sep 15, 2020 at 11:53:49PM +0800, Chengming Zhou wrote:
>> In the cgroup v1, we can use netlink interface to get cgroupstats for
>> a cgroup. But it has been excluded from cgroup v2 interface intentionally
>>
add
these cgroupstats numbers to the cgroup.stat file, and change the
admin-guide doc accordingly.
Reported-by: Daowen Luo
Tested-by: Chengming Zhou
Signed-off-by: Muchun Song
Signed-off-by: Chengming Zhou
---
Documentation/admin-guide/cgroup-v2.rst | 15 ++
kernel/cgrou
The following commit has been merged into the sched/core branch of tip:
Commit-ID: e6560d58334ca463061ade733674abc8dd0df9bd
Gitweb:
https://git.kernel.org/tip/e6560d58334ca463061ade733674abc8dd0df9bd
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:59 +08:00
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 311b293811a31929c72c790eff48cf767561589f
Gitweb:
https://git.kernel.org/tip/311b293811a31929c72c790eff48cf767561589f
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:56 +08:00
The following commit has been merged into the sched/core branch of tip:
Commit-ID: f3f7feec57b9141dfed9825874d0191b1ac18ad2
Gitweb:
https://git.kernel.org/tip/f3f7feec57b9141dfed9825874d0191b1ac18ad2
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:57 +08:00
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 7fae6c8171d20ac55402930ee8ae760cf85dff7b
Gitweb:
https://git.kernel.org/tip/7fae6c8171d20ac55402930ee8ae760cf85dff7b
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:57 +08:00
The following commit has been merged into the sched/core branch of tip:
Commit-ID: e7fcd762282332f765af2035a9568fb126fa3c01
Gitweb:
https://git.kernel.org/tip/e7fcd762282332f765af2035a9568fb126fa3c01
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:56 +08:00
The following commit has been merged into the sched/core branch of tip:
Commit-ID: 4117cebf1a9fcbf35b9aabf0e37b6c5eea296798
Gitweb:
https://git.kernel.org/tip/4117cebf1a9fcbf35b9aabf0e37b6c5eea296798
Author:Chengming Zhou
AuthorDate:Wed, 03 Mar 2021 11:46:59 +08:00
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