/etc/systemd/network/eth0.network
[Match] Name=eth0 [Network] DHCP=yes [Address] Address=104.21.64.95/32 [Address] Address=2606:4700:3037::ac43::1/64
Tag: 原创
Float-point fused Multiply-Add AArch64 vs LoongArch64
AA64: fmadd d, n, m, a: d = a + n * m
LA64: fmadd d, j, k, a: d = a + j * k
AA64: fmsub d, n, m, a: d = a + (-n) * m
d = a - n * m
d = - (n * m - a)
LA64: fnmsub d, j, k, a: d = - (j * k - a)
d = a - j * k
d = a + (-j) * k
AA64: fnmadd d, n, m, a: d = (-a) + (-n) * m
d = - (n * m + a)
LA64: fnmadd d, j, k, a: d = - (j * k + a)
d = (-a) + (-n * m)
AA64: fnmsub d, n, m, a: d = (-a) + n * m
d = n * m - a
LA64: fmsub d, j, k, a: d = j * k - a
d = (-a) + j * k
IP addr-label persistent by systemd
This is an example shows how to make IP address label persistent by systemd-networkd.
/etc/systemd/network/eth0.network :
[Match] Name=eth0 [Network] Address=192.168.0.1/24 Gateway=192.168.0.254 DNS=192.168.0.254 [IPv6AddressLabel] Label=100 Prefix=2409::/16 [IPv6AddressLabel] Label=100 Prefix=2606::/16
It’s successful if you can see labels that you configured :
$ ip addrlprefix ::1/128 label 0 prefix ::/96 label 3 prefix ::ffff:0.0.0.0/96 label 4 prefix 2001::/32 label 6 prefix 2001:10::/28 label 7 prefix 2606::/16 dev br0 label 100 prefix 2409::/16 dev br0 label 100 prefix 3ffe::/16 label 12 prefix 2002::/16 label 2 prefix fec0::/10 label 11 prefix fc00::/7 label 5 prefix ::/0 label 1
Hotspot stress diagnostic options
SafepointALot: Generate a lot of safepoints. This works with GuaranteedSafepointInterval.
HandshakeALot: Generate a lot of handshakes. This works with GuaranteedSafepointInterval.
DeoptimizeALot: Deoptimize at every exit from the runtime system.
ZombieALot: Create zombies (non-entrant) at exit from the runtime system.
WalkStackALot: Trace stack (no print) at every exit from the runtime system.
DeoptimizeObjectsALot: For testing purposes concurrent threads revert optimizations based on escape analysis at intervals given with DeoptimizeObjectsALotInterval=n. The thread count is given with DeoptimizeObjectsALotThreadCountSingle and DeoptimizeObjectsALotThreadCountAll.
DontYieldALot: Throw away obvious excess yield calls.
StringDeduplicationResizeALot: Force more frequent table resizing.
DeoptimizeNMethodBarriersALot: Make nmethod barriers deoptimise a lot.
dnsmasq can’t resolve domains that points to reserved addresses
The dnsmasq is enables rebind protection by default, this reject DNS records that contains reserved address (RFC1918).
Remove argument to disable it:
--stop-dns-rebind
OpenWrt
LUCI
Menu: Network->DHCP and DNS
Unchecked Rebind protection.
Dump rerun commands of jtreg
make test JTREG="VERBOSE=all" ...
make run-test JTREG="VERBOSE=all"
RK3399: Tune ethernet irq affinity
Handle interrupts of ethernet device on high performance cpus.
/etc/systemd/system/irq-eth0.service
[Unit] Description=IRQ SMP Affinity After=network.target [Service] Type=oneshot ExecStart=/usr/bin/bash -c 'echo 4-5 > /proc/irq/31/smp_affinity_list' [Install] WantedBy=multi-user.target
OpenSSH 8.8 ssh-rsa
Unable to negotiate with 192.168.0.1 port 22: no matching host key type found. Their offer: ssh-rsa
Workaround:
Host 192.168.0.1
HostkeyAlgorithms +ssh-rsa
PubkeyAcceptedAlgorithms +ssh-rsa
一语成谶
“Across the Great Wall, we can reach every corner in the world”
Creating swap files faster
sudo fallocate -l 100G /path/to/swap.img
sudo chmod 0600 /path/to/swap.img
sudo mkswap /path/to/swap.img