Criticism of Linux rise in prominence of operating system-level virtualization using Linux has raised the profile of attacks against the kernel, and that Linus Torvalds is reticent to add mitigations against kernel-level attacks in official releases. Linux 4.12, released in 2017, enabled KASLR by default, but its effectiveness is debated. Con Kolivas, a former kernel developer, tried to optimize the kernel scheduler for interactive desktop use. He finally dropped the support for his patches due to the lack of appreciation for his development. In the 2007 interview "Why I quit: kernel developer Con Kolivas" he stated: At LinuxCon 2009, Linux creator Linus Torvalds
Tanenbaum–Torvalds debate titled "Can We Make Operating Systems Reliable and Secure?". While Tanenbaum himself has mentioned that he did not write the article to renew the debate on kernel design, the juxtaposition of the article and an archived copy of the 1992 debate on the technology site Slashdot caused the subject to be rekindled. Torvalds posted a rebuttal of Tanenbaum's arguments via an online discussion forum, and several technology news sites began reporting the issue. This prompted Jonathan Shapiro to respond that most of the field-proven reliable and secure computer systems use a more microkernel-like approach. Tanenbaum–Torvalds debate The Tanenbaum–Torvalds debate was