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I have recently back-ported the rfc2988bis changes (initRTO=1 and fallack) to the redhat 2.6.32 kernel – find the patch on my github account at @ https://github.com/alouche/redhat-2.6.32-kernel-patches/blob/master/rfc2988bis.patch On short lived connections with a lot of 3WHS, a lower initial RTO will improve 3WHS latency by 2*2000ms*X% (X% being the average of packet drops of a specific [...]
Since the 2.6.23 kernel, the Linux kernel process scheduler previously O(1) was replaced by CFS – a Completely Fair Scheduler. CFS uses a red-black tree as data-structure and unlike previous Unix process scheduler does not account a traditional time slice of process execution but accounts what is referred as the process virtual runtime, expressed in [...]
RXDSK is a project currently in development which is worth checking out and keeping an eye on. It is quiet similar to ZRAM (previously compache) and TMPFS/RAMFS but has some minor differences which renders it more flexible for generic usage. ZXDSK allows for example an export of the ram disk to a physical disk, making [...]
I have created a working Red Hat/CentOS 6 Xen Dom0 Kernel including backport patches. I had to hack to the blktap driver hooks to finalize support of the module due to the interface changes in the recent vanilla kernel. But all is working. [root@blackhole1 ~]# uname -rsm Linux 2.6.32-131.12.1.el6.alouche.xen.dom0.x86_64 x86_64 [root@blackhole1 ~]# xm list Name [...]
KSM, simply put is a service daemon which scans the page addresses to find duplicate pages, merges them and therefore reduces the memory density. The code used in this post as example can be found under /mm/ksm.c in the kernel source. Before continuing, it is important to keep in mind that: – KSM uses a [...]