Changes from RFC v3 -> PATCH v1:
- Updated selftest to use ksft_print_msg instead of fprintf(stderr, ...)
(Muhammad Usama Anjum)
- Included more detail in patch skipping pmd_young with force_scan
(Huang, Ying)
- Deferred reaccess histogram as a followup
- Removed per-memcg page age interval configs for simplicity
Changes from RFC v2 -> RFC v3:
- Update to v6.8
- Added an aging kernel thread (gated behind config)
- Added basic selftests for sysfs interface files
- Track swapped out pages for reaccesses
- Refactoring and cleanup
- Dropped the virtio-balloon extension to make things manageable
Changes from RFC v1 -> RFC v2:
- Refactored the patchs into smaller pieces
- Renamed interfaces and functions from wss to wsr (Working Set Reporting)
- Fixed build errors when CONFIG_WSR is not set
- Changed working_set_num_bins to u8 for virtio-balloon
- Added support for per-NUMA node reporting for virtio-balloon
[rfc v1]
https://lore.kernel.org/linux-mm/20230509185419.1088297-1-yuanchu@google.co…
[rfc v2]
https://lore.kernel.org/linux-mm/20230621180454.973862-1-yuanchu@google.com/
[rfc v3]
https://lore.kernel.org/linux-mm/20240327213108.2384666-1-yuanchu@google.co…
This patch series provides workingset reporting of user pages in
lruvecs, of which coldness can be tracked by accessed bits and fd
references. However, the concept of workingset applies generically to
all types of memory, which could be kernel slab caches, discardable
userspace caches (databases), or CXL.mem. Therefore, data sources might
come from slab shrinkers, device drivers, or the userspace. IMO, the
kernel should provide a set of workingset interfaces that should be
generic enough to accommodate the various use cases, and be extensible
to potential future use cases. The current proposed interfaces are not
sufficient in that regard, but I would like to start somewhere, solicit
feedback, and iterate.
Use cases
==========
Job scheduling
On overcommitted hosts, workingset information allows the job scheduler
to right-size each job and land more jobs on the same host or NUMA node,
and in the case of a job with increasing workingset, policy decisions
can be made to migrate other jobs off the host/NUMA node, or oom-kill
the misbehaving job. If the job shape is very different from the machine
shape, knowing the workingset per-node can also help inform page
allocation policies.
Proactive reclaim
Workingset information allows the a container manager to proactively
reclaim memory while not impacting a job's performance. While PSI may
provide a reactive measure of when a proactive reclaim has reclaimed too
much, workingset reporting allows the policy to be more accurate and
flexible.
Ballooning (similar to proactive reclaim)
While this patch series does not extend the virtio-balloon device,
balloon policies benefit from workingset to more precisely determine
the size of the memory balloon. On desktops/laptops/mobile devices where
memory is scarce and overcommitted, the balloon sizing in multiple VMs
running on the same device can be orchestrated with workingset reports
from each one.
Promotion/Demotion
Similar to proactive reclaim, a workingset report enables demotion to a
slower tier of memory.
For promotion, the workingset report interfaces need to be extended to
report hotness and gather hotness information from the devices[1].
[1]
https://www.opencompute.org/documents/ocp-cms-hotness-tracking-requirements…
Sysfs and Cgroup Interfaces
==========
The interfaces are detailed in the patches that introduce them. The main
idea here is we break down the workingset per-node per-memcg into time
intervals (ms), e.g.
1000 anon=137368 file=24530
20000 anon=34342 file=0
30000 anon=353232 file=333608
40000 anon=407198 file=206052
9223372036854775807 anon=4925624 file=892892
I realize this does not generalize well to hotness information, but I
lack the intuition for an abstraction that presents hotness in a useful
way. Please advise.
Implementation
==========
Currently, the reporting of user pages is based off of MGLRU, and
therefore requires CONFIG_LRU_GEN=y. We would benefit from more MGLRU
generations for a more fine-grained workingset report. I will make the
generation count configurable in the next version. The workingset
reporting mechanism is gated behind CONFIG_WORKINGSET_REPORT, and the
aging thread is behind CONFIG_WORKINGSET_REPORT_AGING.
Yuanchu Xie (7):
mm: multi-gen LRU: ignore non-leaf pmd_young for force_scan=true
mm: aggregate working set information into histograms
mm: use refresh interval to rate-limit workingset report aggregation
mm: report workingset during memory pressure driven scanning
mm: extend working set reporting to memcgs
mm: add kernel aging thread for workingset reporting
selftest: test system-wide workingset reporting
drivers/base/node.c | 6 +
include/linux/memcontrol.h | 5 +
include/linux/mmzone.h | 9 +
include/linux/workingset_report.h | 97 ++++
mm/Kconfig | 15 +
mm/Makefile | 2 +
mm/internal.h | 17 +
mm/memcontrol.c | 184 +++++-
mm/mm_init.c | 2 +
mm/mmzone.c | 2 +
mm/vmscan.c | 85 ++-
mm/workingset_report.c | 545 ++++++++++++++++++
mm/workingset_report_aging.c | 127 ++++
tools/testing/selftests/mm/.gitignore | 1 +
tools/testing/selftests/mm/Makefile | 3 +
.../testing/selftests/mm/workingset_report.c | 317 ++++++++++
.../testing/selftests/mm/workingset_report.h | 39 ++
.../selftests/mm/workingset_report_test.c | 332 +++++++++++
18 files changed, 1786 insertions(+), 2 deletions(-)
create mode 100644 include/linux/workingset_report.h
create mode 100644 mm/workingset_report.c
create mode 100644 mm/workingset_report_aging.c
create mode 100644 tools/testing/selftests/mm/workingset_report.c
create mode 100644 tools/testing/selftests/mm/workingset_report.h
create mode 100644 tools/testing/selftests/mm/workingset_report_test.c
--
2.45.0.rc1.225.g2a3ae87e7f-goog
There is no need to add the name to ns_list again if the netns already
recoreded.
Fixes: 25ae948b4478 ("selftests/net: add lib.sh")
Signed-off-by: Hangbin Liu <liuhangbin(a)gmail.com>
---
tools/testing/selftests/net/lib.sh | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
index f9fe182dfbd4..56a9454b7ba3 100644
--- a/tools/testing/selftests/net/lib.sh
+++ b/tools/testing/selftests/net/lib.sh
@@ -73,15 +73,17 @@ setup_ns()
local ns=""
local ns_name=""
local ns_list=""
+ local ns_exist=
for ns_name in "$@"; do
# Some test may setup/remove same netns multi times
if unset ${ns_name} 2> /dev/null; then
ns="${ns_name,,}-$(mktemp -u XXXXXX)"
eval readonly ${ns_name}="$ns"
+ ns_exist=false
else
eval ns='$'${ns_name}
cleanup_ns "$ns"
-
+ ns_exist=true
fi
if ! ip netns add "$ns"; then
@@ -90,7 +92,7 @@ setup_ns()
return $ksft_skip
fi
ip -n "$ns" link set lo up
- ns_list="$ns_list $ns"
+ ! $ns_exist && ns_list="$ns_list $ns"
done
NS_LIST="$NS_LIST $ns_list"
}
--
2.43.0
This patch series implements a new char misc driver, /dev/ntsync, which is used
to implement Windows NT synchronization primitives.
NT synchronization primitives are unique in that the wait functions both are
vectored, operate on multiple types of object with different behaviour (mutex,
semaphore, event), and affect the state of the objects they wait on. This model
is not compatible with existing kernel synchronization objects or interfaces,
and therefore the ntsync driver implements its own wait queues and locking.
Hence I would like to request review from someone familiar with locking to make
sure that the usage of low-level kernel primitives is correct and that the wait
queues work as intended, and to that end I've CC'd the locking maintainers.
== Background ==
The Wine project emulates the Windows API in user space. One particular part of
that API, namely the NT synchronization primitives, have historically been
implemented via RPC to a dedicated "kernel" process. However, more recent
applications use these APIs more strenuously, and the overhead of RPC has become
a bottleneck.
The NT synchronization APIs are too complex to implement on top of existing
primitives without sacrificing correctness. Certain operations, such as
NtPulseEvent() or the "wait-for-all" mode of NtWaitForMultipleObjects(), require
direct control over the underlying wait queue, and implementing a wait queue
sufficiently robust for Wine in user space is not possible. This proposed
driver, therefore, implements the problematic interfaces directly in the Linux
kernel.
This driver was presented at Linux Plumbers Conference 2023. For those further
interested in the history of synchronization in Wine and past attempts to solve
this problem in user space, a recording of the presentation can be viewed here:
https://www.youtube.com/watch?v=NjU4nyWyhU8
== Performance ==
The gain in performance varies wildly depending on the application in question
and the user's hardware. For some games NT synchronization is not a bottleneck
and no change can be observed, but for others frame rate improvements of 50 to
150 percent are not atypical. The following table lists frame rate measurements
from a variety of games on a variety of hardware, taken by users Dmitry
Skvortsov, FuzzyQuils, OnMars, and myself:
Game Upstream ntsync improvement
===========================================================================
Anger Foot 69 99 43%
Call of Juarez 99.8 224.1 125%
Dirt 3 110.6 860.7 678%
Forza Horizon 5 108 160 48%
Lara Croft: Temple of Osiris 141 326 131%
Metro 2033 164.4 199.2 21%
Resident Evil 2 26 77 196%
The Crew 26 51 96%
Tiny Tina's Wonderlands 130 360 177%
Total War Saga: Troy 109 146 34%
===========================================================================
== Patches ==
The intended semantics of the patches are broadly intended to match those of the
corresponding Windows functions. For those not already familiar with the Windows
functions (or their undocumented behaviour), patch 27/27 provides a detailed
specification, and individual patches also include a brief description of the
API they are implementing.
The patches making use of this driver in Wine can be retrieved or browsed here:
https://repo.or.cz/wine/zf.git/shortlog/refs/heads/ntsync5
== Implementation ==
Some aspects of the implementation may deserve particular comment:
* In the interest of performance, each object is governed only by a single
spinlock. However, NTSYNC_IOC_WAIT_ALL requires that the state of multiple
objects be changed as a single atomic operation. In order to achieve this, we
first take a device-wide lock ("wait_all_lock") any time we are going to lock
more than one object at a time.
The maximum number of objects that can be used in a vectored wait, and
therefore the maximum that can be locked simultaneously, is 64. This number is
NT's own limit.
The acquisition of multiple spinlocks will degrade performance. This is a
conscious choice, however. Wait-for-all is known to be a very rare operation
in practice, especially with counts that approach the maximum, and it is the
intent of the ntsync driver to optimize wait-for-any at the expense of
wait-for-all as much as possible.
* NT mutexes are tied to their threads on an OS level, and the kernel includes
builtin support for "robust" mutexes. In order to keep the ntsync driver
self-contained and avoid touching more code than necessary, it does not hook
into task exit nor use pids.
Instead, the user space emulator is expected to manage thread IDs and pass
them as an argument to any relevant functions; this is the "owner" field of
ntsync_wait_args and ntsync_mutex_args.
When the emulator detects that a thread dies, it should therefore call
NTSYNC_IOC_MUTEX_KILL on any open mutexes.
* ntsync is module-capable mostly because there was nothing preventing it, and
because it aided development. It is not a hard requirement, though.
== Previous versions ==
Changes from v3:
* Add .gitignore and use KHDR_INCLUDES in selftest build files, per Muhammad
Usama Anjum.
* Try to explain why we are rolling our own primitives a little better, per Greg
Kroah-Hartman.
* Link to v3: https://lore.kernel.org/lkml/20240329000621.148791-1-zfigura@codeweavers.co…
* Link to v2: https://lore.kernel.org/lkml/20240219223833.95710-1-zfigura@codeweavers.com/
* Link to v1: https://lore.kernel.org/lkml/20240214233645.9273-1-zfigura@codeweavers.com/
* Link to RFC v2: https://lore.kernel.org/lkml/20240131021356.10322-1-zfigura@codeweavers.com/
* Link to RFC v1: https://lore.kernel.org/lkml/20240124004028.16826-1-zfigura@codeweavers.com/
Elizabeth Figura (27):
ntsync: Introduce NTSYNC_IOC_WAIT_ANY.
ntsync: Introduce NTSYNC_IOC_WAIT_ALL.
ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX.
ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK.
ntsync: Introduce NTSYNC_IOC_MUTEX_KILL.
ntsync: Introduce NTSYNC_IOC_CREATE_EVENT.
ntsync: Introduce NTSYNC_IOC_EVENT_SET.
ntsync: Introduce NTSYNC_IOC_EVENT_RESET.
ntsync: Introduce NTSYNC_IOC_EVENT_PULSE.
ntsync: Introduce NTSYNC_IOC_SEM_READ.
ntsync: Introduce NTSYNC_IOC_MUTEX_READ.
ntsync: Introduce NTSYNC_IOC_EVENT_READ.
ntsync: Introduce alertable waits.
selftests: ntsync: Add some tests for semaphore state.
selftests: ntsync: Add some tests for mutex state.
selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ANY.
selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ALL.
selftests: ntsync: Add some tests for wakeup signaling with
WINESYNC_IOC_WAIT_ANY.
selftests: ntsync: Add some tests for wakeup signaling with
WINESYNC_IOC_WAIT_ALL.
selftests: ntsync: Add some tests for manual-reset event state.
selftests: ntsync: Add some tests for auto-reset event state.
selftests: ntsync: Add some tests for wakeup signaling with events.
selftests: ntsync: Add tests for alertable waits.
selftests: ntsync: Add some tests for wakeup signaling via alerts.
selftests: ntsync: Add a stress test for contended waits.
maintainers: Add an entry for ntsync.
docs: ntsync: Add documentation for the ntsync uAPI.
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/ntsync.rst | 399 +++++
MAINTAINERS | 9 +
drivers/misc/ntsync.c | 925 ++++++++++-
include/uapi/linux/ntsync.h | 39 +
tools/testing/selftests/Makefile | 1 +
.../selftests/drivers/ntsync/.gitignore | 1 +
.../testing/selftests/drivers/ntsync/Makefile | 7 +
tools/testing/selftests/drivers/ntsync/config | 1 +
.../testing/selftests/drivers/ntsync/ntsync.c | 1407 +++++++++++++++++
10 files changed, 2786 insertions(+), 4 deletions(-)
create mode 100644 Documentation/userspace-api/ntsync.rst
create mode 100644 tools/testing/selftests/drivers/ntsync/.gitignore
create mode 100644 tools/testing/selftests/drivers/ntsync/Makefile
create mode 100644 tools/testing/selftests/drivers/ntsync/config
create mode 100644 tools/testing/selftests/drivers/ntsync/ntsync.c
base-commit: ebbc1a4789c666846b9854ef845a37a64879e5f9
--
2.43.0
Hi everyone,
My name is Abhinav Saxena. I am a graduate student at the University
of Calgary. This is my first patch series for the Linux kernel. I am
applying for the "Linux kernel Bug Fixing Summer Unpaid
2024". Apologies in advance if I made any trivial mistakes :)
This patch mainly includes issues reported by checkpatch.pl. The
changes include:
- Running clang-format on `binderfs_test.c` to fix formatting issues.
- Updates the macro close_prot_errno_disarm macro.
Testing: I tested patches on my local machine (ARM64 ubuntu) with
checkpatch.pl and running the selftests.
Best,
Abhinav
Abhinav Saxena (4):
run clang-format on bindergfs test
update close_prot_errno_disarm macro to do{...}while(false) structure
for safety
Macro argument 'fd' may be better as '(fd)' to avoid precedence issues
add missing a blank line after declarations; fix alignment formatting
.../filesystems/binderfs/binderfs_test.c | 204 +++++++++++-------
1 file changed, 126 insertions(+), 78 deletions(-)
--
2.34.1
Add support for (yet again) more RVA23U64 missing extensions. Add
support for Zcmop, Zca, Zcf, Zcd and Zcb extensions isa string parsing,
hwprobe and kvm support. Zce, Zcmt and Zcmp extensions have been left
out since they target microcontrollers/embedded CPUs and are not needed
by RVA23U64.
Since Zc* extensions states that C implies Zca, Zcf (if F and RV32), Zcd
(if D), this series modifies the way ISA string is parsed and now does
it in two phases. First one parses the string and the second one
validates it for the final ISA description.
This series is based on the Zimop one [1]. An additional fix [2] should
be applied to correctly test that series.
Link: https://lore.kernel.org/linux-riscv/20240404103254.1752834-1-cleger@rivosin… [1]
Link: https://lore.kernel.org/all/20240409143839.558784-1-cleger@rivosinc.com/ [2]
---
v4:
- Modify validate() callbacks to return an 0, -EPROBEDEFER or another
error.
- v3: https://lore.kernel.org/all/20240423124326.2532796-1-cleger@rivosinc.com/
v3:
- Fix typo "exists" -> "exist"
- Remove C implies Zca, Zcd, Zcf, dt-bindings rules
- Rework ISA string resolver to handle dependencies
- v2: https://lore.kernel.org/all/20240418124300.1387978-1-cleger@rivosinc.com/
v2:
- Add Zc* dependencies validation in dt-bindings
- v1: https://lore.kernel.org/lkml/20240410091106.749233-1-cleger@rivosinc.com/
Clément Léger (11):
dt-bindings: riscv: add Zca, Zcf, Zcd and Zcb ISA extension
description
riscv: add ISA extensions validation
riscv: add ISA parsing for Zca, Zcf, Zcd and Zcb
riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensions
RISC-V: KVM: Allow Zca, Zcf, Zcd and Zcb extensions for Guest/VM
KVM: riscv: selftests: Add some Zc* extensions to get-reg-list test
dt-bindings: riscv: add Zcmop ISA extension description
riscv: add ISA extension parsing for Zcmop
riscv: hwprobe: export Zcmop ISA extension
RISC-V: KVM: Allow Zcmop extension for Guest/VM
KVM: riscv: selftests: Add Zcmop extension to get-reg-list test
Documentation/arch/riscv/hwprobe.rst | 24 ++
.../devicetree/bindings/riscv/extensions.yaml | 90 ++++++
arch/riscv/include/asm/cpufeature.h | 1 +
arch/riscv/include/asm/hwcap.h | 5 +
arch/riscv/include/uapi/asm/hwprobe.h | 5 +
arch/riscv/include/uapi/asm/kvm.h | 5 +
arch/riscv/kernel/cpufeature.c | 259 ++++++++++++------
arch/riscv/kernel/sys_hwprobe.c | 5 +
arch/riscv/kvm/vcpu_onereg.c | 10 +
.../selftests/kvm/riscv/get-reg-list.c | 20 ++
10 files changed, 337 insertions(+), 87 deletions(-)
--
2.43.0