Linus released the 3.1 kernel while sitting in the security session at the Kernel Summit; he has not yet gotten around to sending an announcement, though. Headline features in this somewhat delayed release include improved Xen memory management, enhancements to process tracing (the PTRACE_SEIZE command), enhancements to lseek() to ease the finding of holes in files, OpenRISC architecture support, and more.
Read more at LWN
