Hey Andrew, Thanks for taking time to review! I appreciate your suggestion and will be supplementing with test results shortly. Best, Lance On Thu, Feb 22, 2024 at 6:12 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, 31 Jan 2024 17:30:11 +0800 Lance Yang <ioworker0@xxxxxxxxx> wrote: > > > Updating the change log. > > > > khugepaged scans the entire address space in the > > background for each given mm, looking for > > opportunities to merge sequences of basic pages > > into huge pages. However, when an mm is inserted > > to the mm_slots list, and the MMF_DISABLE_THP > > flag is set later, this scanning process becomes > > unnecessary for that mm and can be skipped to > > avoid redundant operations, especially in scenarios > > with a large address space. > > > > This commit introduces a check before each scanning > > process to test the MMF_DISABLE_THP flag for the > > given mm; if the flag is set, the scanning process is > > bypassed, thereby improving the efficiency of khugepaged. > > > > This optimization is not a correctness issue but rather an > > enhancement to save expensive checks on each VMA > > when userspace cannot prctl itself before spawning > > into the new process. > > > > On some servers within our company, we deploy a > > daemon responsible for monitoring and updating local > > applications. Some applications prefer not to use THP, > > so the daemon calls prctl to disable THP before fork/exec. > > Conversely, for other applications, the daemon calls prctl > > to enable THP before fork/exec. > > > > Ideally, the daemon should invoke prctl after the fork, > > but its current implementation follows the described > > approach. In the Go standard library, there is no direct > > encapsulation of the fork system call; instead, fork and > > execve are combined into one through syscall.ForkExec. > > I pasted the above into the v1 patch's changelog. > > However I'm not seeing a good level of reviewer enthusiasm. Pertially > because of the lack of quantitative testing results. Is is possible to > generate such results, to give people an overall feel of the > desirability of this change? >
