(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Sat, 11 Feb 2023 06:54:45 +0000 bugzilla-daemon@xxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=217022 > > Bug ID: 217022 > Summary: Extremely Slow Hugepage Allocation > Product: Memory Management > Version: 2.5 > Kernel Version: 5.15 > Hardware: All > OS: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: Page Allocator > Assignee: akpm@xxxxxxxxxxxxxxxxxxxx > Reporter: y.liu@xxxxxxxxxxx > Regression: No > > Created attachment 303713 > --> https://bugzilla.kernel.org/attachment.cgi?id=303713&action=edit > perf data and kernel config > > We have some ICE lake server with 1TB memory installed. They were all running > at 5.10.x branch LTS kernel and run fine. After we upgraded kernel to 5.15.x > LTS kernel, the booting process were extremely slow. After some analysis, we > realized that was caused by hugepage allocation. Our system used sysctl.conf to > allocate hugepage at the boot time. In fact, "echo 960 > nr_hugepages" had the > same effect. The only way to do a fast allocation is to use boot cmd option: > "default_hugepagesz=1G hugepages=960". > > Our System is Xeon W3375 with 1TB memory installed. But this bug also occured > with Xeon 8180 with 1.5TB memory too. Our OS is Gentoo Linux. With 5.10.x, the > allocation speed is around 300GB/s, and 5.15.x only had 30GB/s. We also tried > 6.1.1, it is the same as 5.15.x . > > We compiled 5.10.163 and 5.15.88 with debug option and used "perf -a -g sleep > 2" to catch kernel functions. Here are two perf outputs. I hope this can help. > > -- > You may reply to this email to add a comment. > > You are receiving this mail because: > You are the assignee for the bug.
