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Hanjun Guo

OS kernel Architect
Huawei
Standard Ticket

I'm a Linux kernel hacker for about 14 years and working for ARM server for more than 11 years, started from ACPI for ARM64 enablement and upstream in Linaro 2013 (work as an assignee, such a good memory!), then I became the ACPI for ARM64 co-maintainer in Linux kernel at 2016. I'm the major contributor and technical leader in Huawei for ARM server enablement, performance tuning, and software-hardware co-design in OS area, talk to me anything about ARM server.

Talks

MAD24-316 MAD24-318 Why TLBI matters on ARM server: scalability issues we found and solutions

Session

Linux kernel

  • Thursday, 16 May 12:10 - 12:35
  • Room: Session 2 | Tenerife I

TLBI is the TLB invalidation which is needed for updating mappings and attributes of the page table, on ARM the TLBI will broadcast to every CPU core in the inner shareable domain, and we found that TLBI affects the scalability a lot on some workload (such as virtual machine) on ARM64 server with many CPU cores. In this presentation, we introduce some scalability mitigations for TLBI such as TLBI by range, batched TLBI in the Linux mainline kernel. Then present the scalability issue we encountered on our ARM server when running VMs, we limit the TLBI in VM cpu context domain then we got about 50% performance boost on a 96 core ARM server.