Optimizing Linux Performance; Set Cpus To Maximum Performance Mode; Set Kernel Sysctl Settings - Qlogic QL45212 User Manual

7–iSCSI Extensions for RDMA

Optimizing Linux Performance

Optimizing Linux Performance
Consider the Linux performance enhancements.

Set CPUs to Maximum Performance Mode

Set the CPU scaling governor to performance by using the following script to set
all CPUs to maximum Performance mode
for CPUFREQ in
/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do [ -f
$CPUFREQ ] || continue; echo -n performance > $CPUFREQ; done
Verify that all CPU cores were set to maximum performance mode by typing the
following command:
cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor

Set Kernel sysctl Settings

Set the kernel sysctl settings as follows:
sysctl -w net.ipv4.tcp_mem="4194304 4194304 4194304"
sysctl -w net.ipv4.tcp_wmem="4096 65536 4194304"
sysctl -w net.ipv4.tcp_rmem="4096 87380 4194304"
sysctl -w net.core.wmem_max=4194304
sysctl -w net.core.rmem_max=4194304
sysctl -w net.core.wmem_default=4194304
sysctl -w net.core.rmem_default=4194304
sysctl -w net.core.netdev_max_backlog=250000
sysctl -w net.ipv4.tcp_timestamps=0
sysctl -w net.ipv4.tcp_sack=1
sysctl -w net.ipv4.tcp_low_latency=1
sysctl -w net.ipv4.tcp_adv_win_scale=1
echo 0 > /proc/sys/vm/nr_hugepages
74 BC0154503-00 C