xtheadvector is a custom extension that is based upon riscv vector
version 0.7.1 [1]. All of the vector routines have been modified to
support this alternative vector version based upon whether xtheadvector
was determined to be supported at boot.
vlenb is not supported on the existing xtheadvector hardware, so a
devicetree property thead,vlenb is added to provide the vlenb to Linux.
There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is
used to request which thead vendor extensions are supported on the
current platform. This allows future vendors to allocate hwprobe keys
for their vendor.
Support for xtheadvector is also added to the vector kselftests.
Signed-off-by: Charlie Jenkins <charlie(a)rivosinc.com>
[1] https://github.com/T-head-Semi/thead-extension-spec/blob/95358cb2cca9489361…
---
This series is a continuation of a different series that was fragmented
into two other series in an attempt to get part of it merged in the 6.10
merge window. The split-off series did not get merged due to a NAK on
the series that added the generic riscv,vlenb devicetree entry. This
series has converted riscv,vlenb to thead,vlenb to remedy this issue.
The original series is titled "riscv: Support vendor extensions and
xtheadvector" [3].
The series titled "riscv: Extend cpufeature.c to detect vendor
extensions" is still under development and this series is based on that
series! [4]
I have tested this with an Allwinner Nezha board. I ran into issues
booting the board after 6.9-rc1 so I applied these patches to 6.8. There
are a couple of minor merge conflicts that do arrise when doing that, so
please let me know if you have been able to boot this board with a 6.9
kernel. I used SkiffOS [1] to manage building the image, but upgraded
the U-Boot version to Samuel Holland's more up-to-date version [2] and
changed out the device tree used by U-Boot with the device trees that
are present in upstream linux and this series. Thank you Samuel for all
of the work you did to make this task possible.
[1] https://github.com/skiffos/SkiffOS/tree/master/configs/allwinner/nezha
[2] https://github.com/smaeul/u-boot/commit/2e89b706f5c956a70c989cd31665f1429e9…
[3] https://lore.kernel.org/all/20240503-dev-charlie-support_thead_vector_6_9-v…
[4] https://lore.kernel.org/lkml/20240719-support_vendor_extensions-v3-4-0af758…
---
Changes in v7:
- Add defs for has_xtheadvector_no_alternatives() and has_xtheadvector()
when vector disabled. (Palmer)
- Link to v6: https://lore.kernel.org/r/20240722-xtheadvector-v6-0-c9af0130fa00@rivosinc.…
Changes in v6:
- Fix return type of is_vector_supported()/is_xthead_supported() to be bool
- Link to v5: https://lore.kernel.org/r/20240719-xtheadvector-v5-0-4b485fc7d55f@rivosinc.…
Changes in v5:
- Rebase on for-next
- Link to v4: https://lore.kernel.org/r/20240702-xtheadvector-v4-0-2bad6820db11@rivosinc.…
Changes in v4:
- Replace inline asm with C (Samuel)
- Rename VCSRs to CSRs (Samuel)
- Replace .insn directives with .4byte directives
- Link to v3: https://lore.kernel.org/r/20240619-xtheadvector-v3-0-bff39eb9668e@rivosinc.…
Changes in v3:
- Add back Heiko's signed-off-by (Conor)
- Mark RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 as a bitmask
- Link to v2: https://lore.kernel.org/r/20240610-xtheadvector-v2-0-97a48613ad64@rivosinc.…
Changes in v2:
- Removed extraneous references to "riscv,vlenb" (Jess)
- Moved declaration of "thead,vlenb" into cpus.yaml and added
restriction that it's only applicable to thead cores (Conor)
- Check CONFIG_RISCV_ISA_XTHEADVECTOR instead of CONFIG_RISCV_ISA_V for
thead,vlenb (Jess)
- Fix naming of hwprobe variables (Evan)
- Link to v1: https://lore.kernel.org/r/20240609-xtheadvector-v1-0-3fe591d7f109@rivosinc.…
---
Charlie Jenkins (12):
dt-bindings: riscv: Add xtheadvector ISA extension description
dt-bindings: cpus: add a thead vlen register length property
riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree
riscv: Add thead and xtheadvector as a vendor extension
riscv: vector: Use vlenb from DT for thead
riscv: csr: Add CSR encodings for CSR_VXRM/CSR_VXSAT
riscv: Add xtheadvector instruction definitions
riscv: vector: Support xtheadvector save/restore
riscv: hwprobe: Add thead vendor extension probing
riscv: hwprobe: Document thead vendor extensions and xtheadvector extension
selftests: riscv: Fix vector tests
selftests: riscv: Support xtheadvector in vector tests
Heiko Stuebner (1):
RISC-V: define the elements of the VCSR vector CSR
Documentation/arch/riscv/hwprobe.rst | 10 +
Documentation/devicetree/bindings/riscv/cpus.yaml | 19 ++
.../devicetree/bindings/riscv/extensions.yaml | 10 +
arch/riscv/Kconfig.vendor | 26 ++
arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi | 3 +-
arch/riscv/include/asm/cpufeature.h | 2 +
arch/riscv/include/asm/csr.h | 15 ++
arch/riscv/include/asm/hwprobe.h | 5 +-
arch/riscv/include/asm/switch_to.h | 2 +-
arch/riscv/include/asm/vector.h | 225 ++++++++++++----
arch/riscv/include/asm/vendor_extensions/thead.h | 42 +++
.../include/asm/vendor_extensions/thead_hwprobe.h | 18 ++
.../include/asm/vendor_extensions/vendor_hwprobe.h | 37 +++
arch/riscv/include/uapi/asm/hwprobe.h | 3 +-
arch/riscv/include/uapi/asm/vendor/thead.h | 3 +
arch/riscv/kernel/cpufeature.c | 54 +++-
arch/riscv/kernel/kernel_mode_vector.c | 8 +-
arch/riscv/kernel/process.c | 4 +-
arch/riscv/kernel/signal.c | 6 +-
arch/riscv/kernel/sys_hwprobe.c | 5 +
arch/riscv/kernel/vector.c | 24 +-
arch/riscv/kernel/vendor_extensions.c | 10 +
arch/riscv/kernel/vendor_extensions/Makefile | 2 +
arch/riscv/kernel/vendor_extensions/thead.c | 18 ++
.../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 ++
tools/testing/selftests/riscv/vector/.gitignore | 3 +-
tools/testing/selftests/riscv/vector/Makefile | 17 +-
.../selftests/riscv/vector/v_exec_initval_nolibc.c | 93 +++++++
tools/testing/selftests/riscv/vector/v_helpers.c | 68 +++++
tools/testing/selftests/riscv/vector/v_helpers.h | 8 +
tools/testing/selftests/riscv/vector/v_initval.c | 22 ++
.../selftests/riscv/vector/v_initval_nolibc.c | 68 -----
.../selftests/riscv/vector/vstate_exec_nolibc.c | 20 +-
.../testing/selftests/riscv/vector/vstate_prctl.c | 295 ++++++++++++---------
34 files changed, 891 insertions(+), 273 deletions(-)
---
base-commit: 554462ced9ac97487c8f725fe466a9c20ed87521
change-id: 20240530-xtheadvector-833d3d17b423
--
- Charlie
Hello all,
This series includes the bulk of libc-related compile fixes accumulated to
support systems using musl, with smaller numbers to follow. These patches
are simple and straightforward, and the series has been tested with the
kernel-patches/bpf CI and locally using mips64el-gcc/musl-libc and QEMU
with an OpenWrt rootfs.
The patches address a few general categories of libc portability issues:
- missing, redundant or incorrect include headers
- disabled GNU header extensions (i.e. missing #define _GNU_SOURCE)
- issues with types and casting
Feedback and suggestions for improvement are welcome!
Thanks,
Tony
Tony Ambardar (19):
selftests/bpf: Use pid_t consistently in test_progs.c
selftests/bpf: Fix compile error from rlim_t in sk_storage_map.c
selftests/bpf: Fix error compiling bpf_iter_setsockopt.c with musl
libc
selftests/bpf: Drop unneeded include in unpriv_helpers.c
selftests/bpf: Drop unneeded include in sk_lookup.c
selftests/bpf: Drop unneeded include in flow_dissector.c
selftests/bpf: Fix missing ARRAY_SIZE() definition in bench.c
selftests/bpf: Fix missing UINT_MAX definitions in benchmarks
selftests/bpf: Fix missing BUILD_BUG_ON() declaration
selftests/bpf: Fix include of <sys/fcntl.h>
selftests/bpf: Fix compiling parse_tcp_hdr_opt.c with musl-libc
selftests/bpf: Fix compiling kfree_skb.c with musl-libc
selftests/bpf: Fix compiling flow_dissector.c with musl-libc
selftests/bpf: Fix compiling tcp_rtt.c with musl-libc
selftests/bpf: Fix compiling core_reloc.c with musl-libc
selftests/bpf: Fix errors compiling lwt_redirect.c with musl libc
selftests/bpf: Fix errors compiling decap_sanity.c with musl libc
selftests/bpf: Fix errors compiling crypto_sanity.c with musl libc
selftests/bpf: Fix errors compiling cg_storage_multi.h with musl libc
tools/testing/selftests/bpf/bench.c | 1 +
tools/testing/selftests/bpf/bench.h | 1 +
tools/testing/selftests/bpf/map_tests/sk_storage_map.c | 2 +-
tools/testing/selftests/bpf/prog_tests/bpf_iter_setsockopt.c | 2 +-
tools/testing/selftests/bpf/prog_tests/core_reloc.c | 1 +
tools/testing/selftests/bpf/prog_tests/crypto_sanity.c | 1 -
tools/testing/selftests/bpf/prog_tests/decap_sanity.c | 1 -
tools/testing/selftests/bpf/prog_tests/flow_dissector.c | 2 +-
tools/testing/selftests/bpf/prog_tests/kfree_skb.c | 1 +
tools/testing/selftests/bpf/prog_tests/lwt_redirect.c | 1 -
tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c | 2 +-
tools/testing/selftests/bpf/prog_tests/parse_tcp_hdr_opt.c | 1 +
tools/testing/selftests/bpf/prog_tests/sk_lookup.c | 1 -
tools/testing/selftests/bpf/prog_tests/tcp_rtt.c | 1 +
tools/testing/selftests/bpf/prog_tests/user_ringbuf.c | 1 +
tools/testing/selftests/bpf/progs/cg_storage_multi.h | 2 --
tools/testing/selftests/bpf/test_progs.c | 2 +-
tools/testing/selftests/bpf/unpriv_helpers.c | 1 -
18 files changed, 12 insertions(+), 12 deletions(-)
--
2.34.1
commit 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
changed the env variable for the architecture from MACHINE to ARCH.
This is preventing 3 required TEST_GEN_FILES from being included when
cross compiling s390x and errors when trying to run the test suite.
This is due to the ARCH variable already being set and the arch folder
name being s390.
Add "s390" to the filtered list to cover this case and have the 3 files
included in the build.
Fixes: 0518dbe97fe6 ("selftests/mm: fix cross compilation with LLVM")
Cc: stable(a)kernel.org
Cc: Mark Brown <broonie(a)kernel.org>
Signed-off-by: Nico Pache <npache(a)redhat.com>
---
tools/testing/selftests/mm/Makefile | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index 901e0d07765b..7b8a5def54a1 100644
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -110,7 +110,7 @@ endif
endif
-ifneq (,$(filter $(ARCH),arm64 ia64 mips64 parisc64 powerpc riscv64 s390x sparc64 x86_64))
+ifneq (,$(filter $(ARCH),arm64 ia64 mips64 parisc64 powerpc riscv64 s390x sparc64 x86_64 s390))
TEST_GEN_FILES += va_high_addr_switch
TEST_GEN_FILES += virtual_address_range
TEST_GEN_FILES += write_to_hugetlbfs
--
2.45.2
'%u' in format string requires 'unsigned int' in __wait_for_test()
but the argument type is 'signed int' that this problem was discovered
by reading code.use macro WTERMSIG like those above usage to
fix the wrong format specifier.
Signed-off-by: Zhu Jun <zhujun2(a)cmss.chinamobile.com>
---
Changes
v1->v2:
modify commit info add how to find the problem in the log
v2->v3:
Seems this can use macro WTERMSIG like those above usage, rather than
changing the print format.
tools/testing/selftests/kselftest_harness.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index dbbbcc6c04ee..f41f4435e9a4 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -1086,7 +1086,7 @@ void __wait_for_test(struct __test_metadata *t)
fprintf(TH_LOG_STREAM,
"# %s: Test ended in some other way [%d]\n",
t->name,
- status);
+ WTERMSIG(status));
}
}
--
2.17.1
In this series from Geliang, modifying MPTCP BPF selftests, we have:
- A new MPTCP subflow BPF program setting socket options per subflow: it
looks better to have this old test program in the BPF selftests to
track regressions and to serve as example.
Note: Nicolas is no longer working for Tessares, but he did this work
while working for them, and his email address is no longer available.
- A new symlink to MPTCP's pm_nl_ctl tool is added in BPF selftests, to
be able to use it instead of 'ip mptcp' which is not supported by the
BPF CI running IPRoute 5.5.0.
- A new MPTCP BPF subtest validating the new BPF program added in the
first patch.
Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
---
Changes in v3:
- Sorry for the delay between v2 and v3, this series was conflicting
with the "add netns helpers", but it looks like it is on hold:
https://lore.kernel.org/cover.1715821541.git.tanggeliang@kylinos.cn
- Patch 1/3 includes "bpf_tracing_net.h", introduced in between.
- New patch 2/3: "selftests/bpf: Add mptcp pm_nl_ctl link".
- Patch 3/3: use the tool introduced in patch 2/3 + SYS_NOFAIL() helper.
- Link to v2: https://lore.kernel.org/r/20240509-upstream-bpf-next-20240506-mptcp-subflow…
Changes in v2:
- Previous patches 1/4 and 2/4 have been dropped from this series:
- 1/4: "selftests/bpf: Handle SIGINT when creating netns":
- A new version, more generic and no longer specific to MPTCP BPF
selftest will be sent later, as part of a new series. (Alexei)
- 2/4: "selftests/bpf: Add RUN_MPTCP_TEST macro":
- Removed, not to hide helper functions in macros. (Alexei)
- The commit message of patch 1/2 has been clarified to avoid some
possible confusions spot by Alexei.
- Link to v1: https://lore.kernel.org/r/20240507-upstream-bpf-next-20240506-mptcp-subflow…
---
Geliang Tang (2):
selftests/bpf: Add mptcp pm_nl_ctl link
selftests/bpf: Add mptcp subflow subtest
Nicolas Rybowski (1):
selftests/bpf: Add mptcp subflow example
MAINTAINERS | 1 +
tools/testing/selftests/bpf/Makefile | 3 +-
tools/testing/selftests/bpf/mptcp_pm_nl_ctl.c | 1 +
tools/testing/selftests/bpf/prog_tests/mptcp.c | 104 ++++++++++++++++++++++
tools/testing/selftests/bpf/progs/mptcp_subflow.c | 59 ++++++++++++
5 files changed, 167 insertions(+), 1 deletion(-)
---
base-commit: fd8db07705c55a995c42b1e71afc42faad675b0b
change-id: 20240506-upstream-bpf-next-20240506-mptcp-subflow-test-faef6654bfa3
Best regards,
--
Matthieu Baerts (NGI0) <matttbe(a)kernel.org>
v15: https://patchwork.kernel.org/project/netdevbpf/list/?series=865481&state=*
====
No material changes in this version, only a fix to linking against
libynl.a from the last version. Per Jakub's instructions I've pulled one
of his patches into this series, and now use the new libynl.a correctly,
I hope.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v15/
v14: https://patchwork.kernel.org/project/netdevbpf/list/?series=865135&archive=…
====
No material changes in this version. Only rebase and re-verification on
top of net-next. v13, I think, raced with commit ebad6d0334793
("net/ipv4: Use nested-BH locking for ipv4_tcp_sk.") being merged to
net-next that caused a patchwork failure to apply. This series should
apply cleanly on commit c4532232fa2a4 ("selftests: net: remove unneeded
IP_GRE config").
I did not wait the customary 24hr as Jakub said it's OK to repost as soon
as I build test the rebased version:
https://lore.kernel.org/netdev/20240625075926.146d769d@kernel.org/
v13: https://patchwork.kernel.org/project/netdevbpf/list/?series=861406&archive=…
====
Major changes:
--------------
This iteration addresses Pavel's review comments, applies his
reviewed-by's, and seeks to fix the patchwork build error (sorry!).
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v13/
v12: https://patchwork.kernel.org/project/netdevbpf/list/?series=859747&state=*
====
Major changes:
--------------
This iteration only addresses one minor comment from Pavel with regards
to the trace printing of netmem, and the patchwork build error
introduced in v11 because I missed doing an allmodconfig build, sorry.
Other than that v11, AFAICT, received no feedback. There is one
discussion about how the specifics of plugging io uring memory through
the page pool, but not relevant to content in this particular patchset,
AFAICT.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v12/
v11: https://patchwork.kernel.org/project/netdevbpf/list/?series=857457&state=*
====
Major Changes:
--------------
v11 addresses feedback received in v10. The major change is the removal
of the memory provider ops as requested by Christoph. We still
accomplish the same thing, but utilizing direct function calls with if
statements rather than generic ops.
Additionally address sparse warnings, bugs and review comments from
folks that reviewed.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v11/
Detailed changelog:
-------------------
- Fixes in netdev_rx_queue_restart() from Pavel & David.
- Remove commit e650e8c3a36f5 ("net: page_pool: create hooks for
custom page providers") from the series to address Christoph's
feedback and rebased other patches on the series on this change.
- Fixed build errors with CONFIG_DMA_SHARED_BUFFER &&
!CONFIG_GENERIC_ALLOCATOR build.
- Fixed sparse warnings pointed out by Paolo.
- Drop unnecessary gro_pull_from_frag0 checks.
- Added Bagas reviewed-by to docs.
Cc: Bagas Sanjaya <bagasdotme(a)gmail.com>
Cc: Steven Rostedt <rostedt(a)goodmis.org>
Cc: Christoph Hellwig <hch(a)infradead.org>
Cc: Nikolay Aleksandrov <razor(a)blackwall.org>
v10: https://patchwork.kernel.org/project/netdevbpf/list/?series=852422&state=*
====
Major Changes:
--------------
v9 was sent right before the merge window closed (sorry!). v10 is almost
a re-send of the series now that the merge window re-opened. Only
rebased to latest net-next and addressed some minor iterative comments
received on v9.
As usual, the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v10/
Detailed changelog:
-------------------
- Fixed tokens leaking in DONTNEED setsockopt (Nikolay).
- Moved net_iov_dma_addr() to devmem.c and made it a devmem specific
helpers (David).
- Rename hook alloc_pages to alloc_netmems as alloc_pages is now
preprocessor macro defined and causes a build error.
v9:
===
Major Changes:
--------------
GVE queue API has been merged. Submitting this version as non-RFC after
rebasing on top of the merged API, and dropped the out of tree queue API
I was carrying on github. Addressed the little feedback v8 has received.
Detailed changelog:
------------------
- Added new patch from David Wei to this series for
netdev_rx_queue_restart()
- Fixed sparse error.
- Removed CONFIG_ checks in netmem_is_net_iov()
- Flipped skb->readable to skb->unreadable
- Minor fixes to selftests & docs.
RFC v8:
=======
Major Changes:
--------------
- Fixed build error generated by patch-by-patch build.
- Applied docs suggestions from Randy.
RFC v7:
=======
Major Changes:
--------------
This revision largely rebases on top of net-next and addresses the feedback
RFCv6 received from folks, namely Jakub, Yunsheng, Arnd, David, & Pavel.
The series remains in RFC because the queue-API ndos defined in this
series are not yet implemented. I have a GVE implementation I carry out
of tree for my testing. A upstreamable GVE implementation is in the
works. Aside from that, in my estimation all the patches are ready for
review/merge. Please do take a look.
As usual the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v7/
Detailed changelog:
- Use admin-perm in netlink API.
- Addressed feedback from Jakub with regards to netlink API
implementation.
- Renamed devmem.c functions to something more appropriate for that
file.
- Improve the performance seen through the page_pool benchmark.
- Fix the value definition of all the SO_DEVMEM_* uapi.
- Various fixes to documentation.
Perf - page-pool benchmark:
---------------------------
Improved performance of bench_page_pool_simple.ko tests compared to v6:
https://pastebin.com/raw/v5dYRg8L
net-next base: 8 cycle fast path.
RFC v6: 10 cycle fast path.
RFC v7: 9 cycle fast path.
RFC v7 with CONFIG_DMA_SHARED_BUFFER disabled: 8 cycle fast path,
same as baseline.
Perf - Devmem TCP benchmark:
---------------------
Perf is about the same regardless of the changes in v7, namely the
removal of the static_branch_unlikely to improve the page_pool benchmark
performance:
189/200gbps bi-directional throughput with RX devmem TCP and regular TCP
TX i.e. ~95% line rate.
RFC v6:
=======
Major Changes:
--------------
This revision largely rebases on top of net-next and addresses the little
feedback RFCv5 received.
The series remains in RFC because the queue-API ndos defined in this
series are not yet implemented. I have a GVE implementation I carry out
of tree for my testing. A upstreamable GVE implementation is in the
works. Aside from that, in my estimation all the patches are ready for
review/merge. Please do take a look.
As usual the full devmem TCP changes including the full GVE driver
implementation is here:
https://github.com/mina/linux/commits/tcpdevmem-v6/
This version also comes with some performance data recorded in the cover
letter (see below changelog).
Detailed changelog:
- Rebased on top of the merged netmem_ref changes.
- Converted skb->dmabuf to skb->readable (Pavel). Pavel's original
suggestion was to remove the skb->dmabuf flag entirely, but when I
looked into it closely, I found the issue that if we remove the flag
we have to dereference the shinfo(skb) pointer to obtain the first
frag to tell whether an skb is readable or not. This can cause a
performance regression if it dirties the cache line when the
shinfo(skb) was not really needed. Instead, I converted the skb->dmabuf
flag into a generic skb->readable flag which can be re-used by io_uring
0-copy RX.
- Squashed a few locking optimizations from Eric Dumazet in the RX path
and the DEVMEM_DONTNEED setsockopt.
- Expanded the tests a bit. Added validation for invalid scenarios and
added some more coverage.
Perf - page-pool benchmark:
---------------------------
bench_page_pool_simple.ko tests with and without these changes:
https://pastebin.com/raw/ncHDwAbn
AFAIK the number that really matters in the perf tests is the
'tasklet_page_pool01_fast_path Per elem'. This one measures at about 8
cycles without the changes but there is some 1 cycle noise in some
results.
With the patches this regresses to 9 cycles with the changes but there
is 1 cycle noise occasionally running this test repeatedly.
Lastly I tried disable the static_branch_unlikely() in
netmem_is_net_iov() check. To my surprise disabling the
static_branch_unlikely() check reduces the fast path back to 8 cycles,
but the 1 cycle noise remains.
Perf - Devmem TCP benchmark:
---------------------
189/200gbps bi-directional throughput with RX devmem TCP and regular TCP
TX i.e. ~95% line rate.
Major changes in RFC v5:
========================
1. Rebased on top of 'Abstract page from net stack' series and used the
new netmem type to refer to LSB set pointers instead of re-using
struct page.
2. Downgraded this series back to RFC and called it RFC v5. This is
because this series is now dependent on 'Abstract page from net
stack'[1] and the queue API. Both are removed from the series to
reduce the patch # and those bits are fairly independent or
pre-requisite work.
3. Reworked the page_pool devmem support to use netmem and for some
more unified handling.
4. Reworked the reference counting of net_iov (renamed from
page_pool_iov) to use pp_ref_count for refcounting.
The full changes including the dependent series and GVE page pool
support is here:
https://github.com/mina/linux/commits/tcpdevmem-rfcv5/
[1] https://patchwork.kernel.org/project/netdevbpf/list/?series=810774
Major changes in v1:
====================
1. Implemented MVP queue API ndos to remove the userspace-visible
driver reset.
2. Fixed issues in the napi_pp_put_page() devmem frag unref path.
3. Removed RFC tag.
Many smaller addressed comments across all the patches (patches have
individual change log).
Full tree including the rest of the GVE driver changes:
https://github.com/mina/linux/commits/tcpdevmem-v1
Changes in RFC v3:
==================
1. Pulled in the memory-provider dependency from Jakub's RFC[1] to make the
series reviewable and mergeable.
2. Implemented multi-rx-queue binding which was a todo in v2.
3. Fix to cmsg handling.
The sticking point in RFC v2[2] was the device reset required to refill
the device rx-queues after the dmabuf bind/unbind. The solution
suggested as I understand is a subset of the per-queue management ops
Jakub suggested or similar:
https://lore.kernel.org/netdev/20230815171638.4c057dcd@kernel.org/
This is not addressed in this revision, because:
1. This point was discussed at netconf & netdev and there is openness to
using the current approach of requiring a device reset.
2. Implementing individual queue resetting seems to be difficult for my
test bed with GVE. My prototype to test this ran into issues with the
rx-queues not coming back up properly if reset individually. At the
moment I'm unsure if it's a mistake in the POC or a genuine issue in
the virtualization stack behind GVE, which currently doesn't test
individual rx-queue restart.
3. Our usecases are not bothered by requiring a device reset to refill
the buffer queues, and we'd like to support NICs that run into this
limitation with resetting individual queues.
My thought is that drivers that have trouble with per-queue configs can
use the support in this series, while drivers that support new netdev
ops to reset individual queues can automatically reset the queue as
part of the dma-buf bind/unbind.
The same approach with device resets is presented again for consideration
with other sticking points addressed.
This proposal includes the rx devmem path only proposed for merge. For a
snapshot of my entire tree which includes the GVE POC page pool support &
device memory support:
https://github.com/torvalds/linux/compare/master...mina:linux:tcpdevmem-v3
[1] https://lore.kernel.org/netdev/f8270765-a27b-6ccf-33ea-cda097168d79@redhat.…
[2] https://lore.kernel.org/netdev/CAHS8izOVJGJH5WF68OsRWFKJid1_huzzUK+hpKbLcL4…
Changes in RFC v2:
==================
The sticking point in RFC v1[1] was the dma-buf pages approach we used to
deliver the device memory to the TCP stack. RFC v2 is a proof-of-concept
that attempts to resolve this by implementing scatterlist support in the
networking stack, such that we can import the dma-buf scatterlist
directly. This is the approach proposed at a high level here[2].
Detailed changes:
1. Replaced dma-buf pages approach with importing scatterlist into the
page pool.
2. Replace the dma-buf pages centric API with a netlink API.
3. Removed the TX path implementation - there is no issue with
implementing the TX path with scatterlist approach, but leaving
out the TX path makes it easier to review.
4. Functionality is tested with this proposal, but I have not conducted
perf testing yet. I'm not sure there are regressions, but I removed
perf claims from the cover letter until they can be re-confirmed.
5. Added Signed-off-by: contributors to the implementation.
6. Fixed some bugs with the RX path since RFC v1.
Any feedback welcome, but specifically the biggest pending questions
needing feedback IMO are:
1. Feedback on the scatterlist-based approach in general.
2. Netlink API (Patch 1 & 2).
3. Approach to handle all the drivers that expect to receive pages from
the page pool (Patch 6).
[1] https://lore.kernel.org/netdev/dfe4bae7-13a0-3c5d-d671-f61b375cb0b4@gmail.c…
[2] https://lore.kernel.org/netdev/CAHS8izPm6XRS54LdCDZVd0C75tA1zHSu6jLVO8nzTLX…
==================
* TL;DR:
Device memory TCP (devmem TCP) is a proposal for transferring data to and/or
from device memory efficiently, without bouncing the data to a host memory
buffer.
* Problem:
A large amount of data transfers have device memory as the source and/or
destination. Accelerators drastically increased the volume of such transfers.
Some examples include:
- ML accelerators transferring large amounts of training data from storage into
GPU/TPU memory. In some cases ML training setup time can be as long as 50% of
TPU compute time, improving data transfer throughput & efficiency can help
improving GPU/TPU utilization.
- Distributed training, where ML accelerators, such as GPUs on different hosts,
exchange data among them.
- Distributed raw block storage applications transfer large amounts of data with
remote SSDs, much of this data does not require host processing.
Today, the majority of the Device-to-Device data transfers the network are
implemented as the following low level operations: Device-to-Host copy,
Host-to-Host network transfer, and Host-to-Device copy.
The implementation is suboptimal, especially for bulk data transfers, and can
put significant strains on system resources, such as host memory bandwidth,
PCIe bandwidth, etc. One important reason behind the current state is the
kernel’s lack of semantics to express device to network transfers.
* Proposal:
In this patch series we attempt to optimize this use case by implementing
socket APIs that enable the user to:
1. send device memory across the network directly, and
2. receive incoming network packets directly into device memory.
Packet _payloads_ go directly from the NIC to device memory for receive and from
device memory to NIC for transmit.
Packet _headers_ go to/from host memory and are processed by the TCP/IP stack
normally. The NIC _must_ support header split to achieve this.
Advantages:
- Alleviate host memory bandwidth pressure, compared to existing
network-transfer + device-copy semantics.
- Alleviate PCIe BW pressure, by limiting data transfer to the lowest level
of the PCIe tree, compared to traditional path which sends data through the
root complex.
* Patch overview:
** Part 1: netlink API
Gives user ability to bind dma-buf to an RX queue.
** Part 2: scatterlist support
Currently the standard for device memory sharing is DMABUF, which doesn't
generate struct pages. On the other hand, networking stack (skbs, drivers, and
page pool) operate on pages. We have 2 options:
1. Generate struct pages for dmabuf device memory, or,
2. Modify the networking stack to process scatterlist.
Approach #1 was attempted in RFC v1. RFC v2 implements approach #2.
** part 3: page pool support
We piggy back on page pool memory providers proposal:
https://github.com/kuba-moo/linux/tree/pp-providers
It allows the page pool to define a memory provider that provides the
page allocation and freeing. It helps abstract most of the device memory
TCP changes from the driver.
** part 4: support for unreadable skb frags
Page pool iovs are not accessible by the host; we implement changes
throughput the networking stack to correctly handle skbs with unreadable
frags.
** Part 5: recvmsg() APIs
We define user APIs for the user to send and receive device memory.
Not included with this series is the GVE devmem TCP support, just to
simplify the review. Code available here if desired:
https://github.com/mina/linux/tree/tcpdevmem
This series is built on top of net-next with Jakub's pp-providers changes
cherry-picked.
* NIC dependencies:
1. (strict) Devmem TCP require the NIC to support header split, i.e. the
capability to split incoming packets into a header + payload and to put
each into a separate buffer. Devmem TCP works by using device memory
for the packet payload, and host memory for the packet headers.
2. (optional) Devmem TCP works better with flow steering support & RSS support,
i.e. the NIC's ability to steer flows into certain rx queues. This allows the
sysadmin to enable devmem TCP on a subset of the rx queues, and steer
devmem TCP traffic onto these queues and non devmem TCP elsewhere.
The NIC I have access to with these properties is the GVE with DQO support
running in Google Cloud, but any NIC that supports these features would suffice.
I may be able to help reviewers bring up devmem TCP on their NICs.
* Testing:
The series includes a udmabuf kselftest that show a simple use case of
devmem TCP and validates the entire data path end to end without
a dependency on a specific dmabuf provider.
** Test Setup
Kernel: net-next with this series and memory provider API cherry-picked
locally.
Hardware: Google Cloud A3 VMs.
NIC: GVE with header split & RSS & flow steering support.
Cc: Pavel Begunkov <asml.silence(a)gmail.com>
Cc: David Wei <dw(a)davidwei.uk>
Cc: Jason Gunthorpe <jgg(a)ziepe.ca>
Cc: Yunsheng Lin <linyunsheng(a)huawei.com>
Cc: Shailend Chand <shailend(a)google.com>
Cc: Harshitha Ramamurthy <hramamurthy(a)google.com>
Cc: Shakeel Butt <shakeel.butt(a)linux.dev>
Cc: Jeroen de Borst <jeroendb(a)google.com>
Cc: Praveen Kaligineedi <pkaligineedi(a)google.com>
Jakub Kicinski (1):
tools: net: package libynl for use in selftests
Mina Almasry (13):
netdev: add netdev_rx_queue_restart()
net: netdev netlink api to bind dma-buf to a net device
netdev: support binding dma-buf to netdevice
netdev: netdevice devmem allocator
page_pool: convert to use netmem
page_pool: devmem support
memory-provider: dmabuf devmem memory provider
net: support non paged skb frags
net: add support for skbs with unreadable frags
tcp: RX path for devmem TCP
net: add SO_DEVMEM_DONTNEED setsockopt to release RX frags
net: add devmem TCP documentation
selftests: add ncdevmem, netcat for devmem TCP
Documentation/netlink/specs/netdev.yaml | 57 +++
Documentation/networking/devmem.rst | 258 +++++++++++
Documentation/networking/index.rst | 1 +
arch/alpha/include/uapi/asm/socket.h | 6 +
arch/mips/include/uapi/asm/socket.h | 6 +
arch/parisc/include/uapi/asm/socket.h | 6 +
arch/sparc/include/uapi/asm/socket.h | 6 +
include/linux/skbuff.h | 61 ++-
include/linux/skbuff_ref.h | 11 +-
include/linux/socket.h | 1 +
include/net/devmem.h | 124 ++++++
include/net/mp_dmabuf_devmem.h | 44 ++
include/net/netdev_rx_queue.h | 5 +
include/net/netmem.h | 208 ++++++++-
include/net/page_pool/helpers.h | 124 ++++--
include/net/page_pool/types.h | 22 +-
include/net/sock.h | 2 +
include/net/tcp.h | 5 +-
include/trace/events/page_pool.h | 30 +-
include/uapi/asm-generic/socket.h | 6 +
include/uapi/linux/netdev.h | 19 +
include/uapi/linux/uio.h | 17 +
net/bpf/test_run.c | 5 +-
net/core/Makefile | 3 +-
net/core/datagram.c | 6 +
net/core/dev.c | 6 +-
net/core/devmem.c | 376 ++++++++++++++++
net/core/gro.c | 3 +-
net/core/netdev-genl-gen.c | 23 +
net/core/netdev-genl-gen.h | 6 +
net/core/netdev-genl.c | 103 +++++
net/core/netdev_rx_queue.c | 74 ++++
net/core/page_pool.c | 362 +++++++++-------
net/core/skbuff.c | 83 +++-
net/core/sock.c | 61 +++
net/ipv4/esp4.c | 3 +-
net/ipv4/tcp.c | 261 +++++++++++-
net/ipv4/tcp_input.c | 13 +-
net/ipv4/tcp_ipv4.c | 16 +
net/ipv4/tcp_minisocks.c | 2 +
net/ipv4/tcp_output.c | 5 +-
net/ipv6/esp6.c | 3 +-
net/packet/af_packet.c | 4 +-
tools/include/uapi/linux/netdev.h | 19 +
tools/net/ynl/Makefile | 6 +-
tools/net/ynl/lib/Makefile | 4 +-
tools/testing/selftests/net/.gitignore | 1 +
tools/testing/selftests/net/Makefile | 9 +
tools/testing/selftests/net/ncdevmem.c | 542 ++++++++++++++++++++++++
tools/testing/selftests/net/ynl.mk | 21 +
50 files changed, 2786 insertions(+), 253 deletions(-)
create mode 100644 Documentation/networking/devmem.rst
create mode 100644 include/net/devmem.h
create mode 100644 include/net/mp_dmabuf_devmem.h
create mode 100644 net/core/devmem.c
create mode 100644 net/core/netdev_rx_queue.c
create mode 100644 tools/testing/selftests/net/ncdevmem.c
create mode 100644 tools/testing/selftests/net/ynl.mk
--
2.45.2.803.g4e1b14247a-goog
If the testing kernel doesn't support setting fdb_max_learned or show
fdb_n_learned, just skip it. Or we will get errors like
./bridge_fdb_learning_limit.sh: line 218: [: null: integer expression expected
./bridge_fdb_learning_limit.sh: line 225: [: null: integer expression expected
Fixes: 6f84090333bb ("selftests: forwarding: bridge_fdb_learning_limit: Add a new selftest")
Signed-off-by: Hangbin Liu <liuhangbin(a)gmail.com>
---
.../forwarding/bridge_fdb_learning_limit.sh | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh b/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
index 0760a34b7114..a21b7085da2e 100755
--- a/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
+++ b/tools/testing/selftests/net/forwarding/bridge_fdb_learning_limit.sh
@@ -178,6 +178,22 @@ fdb_del()
check_err $? "Failed to remove a FDB entry of type ${type}"
}
+check_fdb_n_learned_support()
+{
+ if ! ip link help bridge 2>&1 | grep -q "fdb_max_learned"; then
+ echo "SKIP: iproute2 too old, missing bridge max learned support"
+ exit $ksft_skip
+ fi
+
+ ip link add dev br0 type bridge
+ local learned=$(fdb_get_n_learned)
+ ip link del dev br0
+ if [ "$learned" == "null" ]; then
+ echo "SKIP: kernel too old; bridge fdb_n_learned feature not supported."
+ exit $ksft_skip
+ fi
+}
+
check_accounting_one_type()
{
local type=$1 is_counted=$2 overrides_learned=$3
@@ -274,6 +290,8 @@ check_limit()
done
}
+check_fdb_n_learned_support
+
trap cleanup EXIT
setup_prepare
--
2.45.0
Based on feedback from Linus[1] and follow-up discussions, change the
suggested file naming for KUnit tests.
Link: https://lore.kernel.org/lkml/CAHk-=wgim6pNiGTBMhP8Kd3tsB7_JTAuvNJ=XYd3wPvvk… [1]
Signed-off-by: Kees Cook <kees(a)kernel.org>
---
Cc: David Gow <davidgow(a)google.com>
Cc: Brendan Higgins <brendan.higgins(a)linux.dev>
Cc: Rae Moar <rmoar(a)google.com>
Cc: John Hubbard <jhubbard(a)nvidia.com>
Cc: Jonathan Corbet <corbet(a)lwn.net>
Cc: Linus Torvalds <torvalds(a)linux-foundation.org>
Cc: linux-kselftest(a)vger.kernel.org
Cc: kunit-dev(a)googlegroups.com
Cc: linux-doc(a)vger.kernel.org
Cc: linux-kernel(a)vger.kernel.org
Cc: linux-hardening(a)vger.kernel.org
---
Documentation/dev-tools/kunit/style.rst | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)
diff --git a/Documentation/dev-tools/kunit/style.rst b/Documentation/dev-tools/kunit/style.rst
index b6d0d7359f00..1538835cd0e2 100644
--- a/Documentation/dev-tools/kunit/style.rst
+++ b/Documentation/dev-tools/kunit/style.rst
@@ -188,15 +188,20 @@ For example, a Kconfig entry might look like:
Test File and Module Names
==========================
-KUnit tests can often be compiled as a module. These modules should be named
-after the test suite, followed by ``_test``. If this is likely to conflict with
-non-KUnit tests, the suffix ``_kunit`` can also be used.
-
-The easiest way of achieving this is to name the file containing the test suite
-``<suite>_test.c`` (or, as above, ``<suite>_kunit.c``). This file should be
-placed next to the code under test.
+Whether a KUnit test is compiled as a separate module or via an
+``#include`` in a core kernel source file, the file should be named
+after the test suite, followed by ``_kunit``, and live in a ``tests``
+subdirectory to avoid conflicting with regular modules (e.g. if "foobar"
+is the core module, then "foobar_kunit" is the KUnit test module) or the
+core kernel source file names (e.g. for tab-completion). Many existing
+tests use a ``_test`` suffix, but this is considered deprecated.
+
+So for the common case, name the file containing the test suite
+``tests/<suite>_kunit.c``. The ``tests`` directory should be placed at
+the same level as the code under test. For example, tests for
+``lib/string.c`` live in ``lib/tests/string_kunit.c``.
If the suite name contains some or all of the name of the test's parent
-directory, it may make sense to modify the source filename to reduce redundancy.
-For example, a ``foo_firmware`` suite could be in the ``foo/firmware_test.c``
-file.
+directory, it may make sense to modify the source filename to reduce
+redundancy. For example, a ``foo_firmware`` suite could be in the
+``tests/foo/firmware_kunit.c`` file.
--
2.34.1