Re: [RFC 2/2] signal: extend pidfd_send_signal() to allow expedited process killing

[Matthew Wilcox]

On Wed, Apr 10, 2019 at 06:43:53PM -0700, Suren Baghdasaryan wrote:
> Add new SS_EXPEDITE flag to be used when sending SIGKILL via
> pidfd_send_signal() syscall to allow expedited memory reclaim of the
> victim process. The usage of this flag is currently limited to SIGKILL
> signal and only to privileged users.

What is the downside of doing expedited memory reclaim?  ie why not do it
every time a process is going to die?