Hi,
Please find the upcoming changes in SRCU for v6.15. The changes can also
be found at:
git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux.git srcu.2025.02.05a
Regards,
Boqun
Paul E. McKenney (20):
srcu: Make Tiny SRCU able to operate in preemptible kernels
srcu: Define SRCU_READ_FLAVOR_ALL in terms of symbols
srcu: Use ->srcu_gp_seq for rcutorture reader batch
srcu: Pull ->srcu_{un,}lock_count into a new srcu_ctr structure
srcu: Make SRCU readers use ->srcu_ctrs for counter selection
srcu: Make Tree SRCU updates independent of ->srcu_idx
srcu: Force synchronization for srcu_get_delay()
srcu: Rename srcu_check_read_flavor_lite() to
srcu_check_read_flavor_force()
srcu: Add SRCU_READ_FLAVOR_SLOWGP to flag need for synchronize_rcu()
srcu: Pull pointer-to-integer conversion into __srcu_ptr_to_ctr()
srcu: Pull integer-to-pointer conversion into __srcu_ctr_to_ptr()
srcu: Move SRCU Tree/Tiny definitions from srcu.h
srcu: Add SRCU-fast readers
rcutorture: Add ability to test srcu_read_{,un}lock_fast()
refscale: Add srcu_read_lock_fast() support using "srcu-fast"
rcutorture: Make scenario SRCU-P use srcu_read_lock_fast()
srcu: Fix srcu_read_unlock_{lite,nmisafe}() kernel-doc
srcu: Document that srcu_{read_lock,down_read}() can share srcu_struct
srcu: Add srcu_down_read_fast() and srcu_up_read_fast()
srcu: Make SRCU-fast also be NMI-safe
include/linux/srcu.h | 102 +++++++--
include/linux/srcutiny.h | 27 ++-
include/linux/srcutree.h | 98 +++++++--
kernel/rcu/rcu.h | 9 +-
kernel/rcu/rcutorture.c | 11 +
kernel/rcu/refscale.c | 32 ++-
kernel/rcu/srcutiny.c | 6 +
kernel/rcu/srcutree.c | 199 +++++++++---------
.../rcutorture/configs/rcu/SRCU-P.boot | 1 +
9 files changed, 359 insertions(+), 126 deletions(-)
--
2.39.5 (Apple Git-154)
v4: https://lore.kernel.org/netdev/20250203223916.1064540-1-almasrymina@google.…
===
v4 mainly addresses the critical driver support issue surfaced in v3 by
Paolo and Stan. Drivers aiming to support netmem_tx should make sure not
to pass the netmem dma-addrs to the dma-mapping APIs, as these dma-addrs
may come from dma-bufs.
Additionally other feedback from v3 is addressed.
Major changes:
- Add helpers to handle netmem dma-addrs. Add GVE support for
netmem_tx.
- Fix binding->tx_vec not being freed on error paths during the
tx binding.
- Add a minimal devmem_tx test to devmem.py.
- Clean up everything obsolete from the cover letter (Paolo).
v3: https://patchwork.kernel.org/project/netdevbpf/list/?series=929401&state=*
===
Address minor comments from RFCv2 and fix a few build warnings and
ynl-regen issues. No major changes.
RFC v2: https://patchwork.kernel.org/project/netdevbpf/list/?series=920056&state=*
=======
RFC v2 addresses much of the feedback from RFC v1. I plan on sending
something close to this as net-next reopens, sending it slightly early
to get feedback if any.
Major changes:
--------------
- much improved UAPI as suggested by Stan. We now interpret the iov_base
of the passed in iov from userspace as the offset into the dmabuf to
send from. This removes the need to set iov.iov_base = NULL which may
be confusing to users, and enables us to send multiple iovs in the
same sendmsg() call. ncdevmem and the docs show a sample use of that.
- Removed the duplicate dmabuf iov_iter in binding->iov_iter. I think
this is good improvment as it was confusing to keep track of
2 iterators for the same sendmsg, and mistracking both iterators
caused a couple of bugs reported in the last iteration that are now
resolved with this streamlining.
- Improved test coverage in ncdevmem. Now multiple sendmsg() are tested,
and sending multiple iovs in the same sendmsg() is tested.
- Fixed issue where dmabuf unmapping was happening in invalid context
(Stan).
====================================================================
The TX path had been dropped from the Device Memory TCP patch series
post RFCv1 [1], to make that series slightly easier to review. This
series rebases the implementation of the TX path on top of the
net_iov/netmem framework agreed upon and merged. The motivation for
the feature is thoroughly described in the docs & cover letter of the
original proposal, so I don't repeat the lengthy descriptions here, but
they are available in [1].
Full outline on usage of the TX path is detailed in the documentation
included with this series.
Test example is available via the kselftest included in the series as well.
The series is relatively small, as the TX path for this feature largely
piggybacks on the existing MSG_ZEROCOPY implementation.
Patch Overview:
---------------
1. Documentation & tests to give high level overview of the feature
being added.
1. Add netmem refcounting needed for the TX path.
2. Devmem TX netlink API.
3. Devmem TX net stack implementation.
4. Make dma-buf unbinding scheduled work to handle TX cases where it gets
freed from contexts where we can't sleep.
5. Add devmem TX documentation.
6. Add scaffolding enabling driver support for netmem_tx. Add helpers, driver
feature flag, and docs to enable drivers to declare netmem_tx support.
7. Guard netmem_tx against being enabled against drivers that don't
support it.
8. Add devmem_tx selftests. Add TX path to ncdevmem and add a test to
devmem.py.
Testing:
--------
Testing is very similar to devmem TCP RX path. The ncdevmem test used
for the RX path is now augemented with client functionality to test TX
path.
* Test Setup:
Kernel: net-next with this RFC and memory provider API cherry-picked
locally.
Hardware: Google Cloud A3 VMs.
NIC: GVE with header split & RSS & flow steering support.
Performance results are not included with this version, unfortunately.
I'm having issues running the dma-buf exporter driver against the
upstream kernel on my test setup. The issues are specific to that
dma-buf exporter and do not affect this patch series. I plan to follow
up this series with perf fixes if the tests point to issues once they're
up and running.
Special thanks to Stan who took a stab at rebasing the TX implementation
on top of the netmem/net_iov framework merged. Parts of his proposal [2]
that are reused as-is are forked off into their own patches to give full
credit.
[1] https://lore.kernel.org/netdev/20240909054318.1809580-1-almasrymina@google.…
[2] https://lore.kernel.org/netdev/20240913150913.1280238-2-sdf@fomichev.me/T/#…
Cc: sdf(a)fomichev.me
Cc: asml.silence(a)gmail.com
Cc: dw(a)davidwei.uk
Cc: Jamal Hadi Salim <jhs(a)mojatatu.com>
Cc: Victor Nogueira <victor(a)mojatatu.com>
Cc: Pedro Tammela <pctammela(a)mojatatu.com>
Cc: Samiullah Khawaja <skhawaja(a)google.com>
Mina Almasry (8):
net: add get_netmem/put_netmem support
net: devmem: Implement TX path
net: devmem: make dmabuf unbinding scheduled work
net: add devmem TCP TX documentation
net: enable driver support for netmem TX
gve: add netmem TX support to GVE DQO-RDA mode
net: check for driver support in netmem TX
selftests: ncdevmem: Implement devmem TCP TX
Stanislav Fomichev (1):
net: devmem: TCP tx netlink api
Documentation/netlink/specs/netdev.yaml | 12 +
Documentation/networking/devmem.rst | 150 ++++++++-
.../networking/net_cachelines/net_device.rst | 1 +
Documentation/networking/netdev-features.rst | 5 +
Documentation/networking/netmem.rst | 14 +-
drivers/net/ethernet/google/gve/gve_main.c | 4 +
drivers/net/ethernet/google/gve/gve_tx_dqo.c | 8 +-
include/linux/netdevice.h | 2 +
include/linux/skbuff.h | 17 +-
include/linux/skbuff_ref.h | 4 +-
include/net/netmem.h | 23 ++
include/net/sock.h | 1 +
include/uapi/linux/netdev.h | 1 +
net/core/datagram.c | 48 ++-
net/core/dev.c | 3 +
net/core/devmem.c | 114 ++++++-
net/core/devmem.h | 69 +++-
net/core/netdev-genl-gen.c | 13 +
net/core/netdev-genl-gen.h | 1 +
net/core/netdev-genl.c | 73 ++++-
net/core/skbuff.c | 48 ++-
net/core/sock.c | 6 +
net/ipv4/ip_output.c | 3 +-
net/ipv4/tcp.c | 46 ++-
net/ipv6/ip6_output.c | 3 +-
net/vmw_vsock/virtio_transport_common.c | 5 +-
tools/include/uapi/linux/netdev.h | 1 +
.../selftests/drivers/net/hw/devmem.py | 28 +-
.../selftests/drivers/net/hw/ncdevmem.c | 300 +++++++++++++++++-
29 files changed, 931 insertions(+), 72 deletions(-)
--
2.48.1.601.g30ceb7b040-goog
The current test marks all unexpected return values as failed and sets ret
to 1. If a test is skipped, the entire test also returns 1, incorrectly
indicating failure.
To fix this, add a skipped variable and set ret to 4 if it was previously
0. Otherwise, keep ret set to 1.
Signed-off-by: Hangbin Liu <liuhangbin(a)gmail.com>
---
tools/testing/selftests/net/fib_nexthops.sh | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/net/fib_nexthops.sh b/tools/testing/selftests/net/fib_nexthops.sh
index 77c83d9508d3..6a58e23e1588 100755
--- a/tools/testing/selftests/net/fib_nexthops.sh
+++ b/tools/testing/selftests/net/fib_nexthops.sh
@@ -76,11 +76,13 @@ log_test()
printf "TEST: %-60s [ OK ]\n" "${msg}"
nsuccess=$((nsuccess+1))
else
- ret=1
- nfail=$((nfail+1))
if [[ $rc -eq $ksft_skip ]]; then
+ [[ $ret -eq 0 ]] && ret=$ksft_skip
+ nskip=$((nskip+1))
printf "TEST: %-60s [SKIP]\n" "${msg}"
else
+ ret=1
+ nfail=$((nfail+1))
printf "TEST: %-60s [FAIL]\n" "${msg}"
fi
@@ -2528,6 +2530,7 @@ done
if [ "$TESTS" != "none" ]; then
printf "\nTests passed: %3d\n" ${nsuccess}
printf "Tests failed: %3d\n" ${nfail}
+ printf "Tests skipped: %2d\n" ${nskip}
fi
exit $ret
--
2.46.0