Linux 4.19 Goes Ahead And Makes Lazy TLB Mode Lazier For Small Performance Benefit

Written by Michael Larabel in Linux Kernel on 16 August 2018 at 07:45 AM EDT. 4 Comments
Last month I wrote about lazy TLB mode improvements on the way to the mainline kernel and this week the changes were indeed merged for the in-development Linux 4.19 kernel.

This minor optimization is about trying to avoid an idle CPU being woken up by a translation look-aside buffer (TLB) flush. With the patch by Rik van Riel, the total CPU on the system is reduced by 1~2% for a memcache test and about 1% for a heavy multi-process netperf test run.

That work was merged as part of the updates in x86-mm-for-linus for the Linux 4.19 merge window with "Make lazy TLB mode even lazier to avoid pointless switch_mm() operations, which reduces CPU load by 1-2% for memcache workloads."

There are also other small improvements and fixes as part of this new kernel's x86 memory management updates.
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