Would also appreciate if this was enabled.
Have a RPi4 with 8GB that runs Rosetta (from BOINC) with idle priority.
The tasks eat about 1G ram each; with 4 running there are quite a few
TLB misses:
root@vadelma:~# perf stat -I 1000 -e
dTLB-load-misses,dTLB-store-misses,iTLB-load-misses -a
# time counts unit events
1.000395577 16,504,784 dTLB-load-misses
1.000395577 1,562,981 dTLB-store-misses
1.000395577 193,640 iTLB-load-misses
2.001569068 18,044,238 dTLB-load-misses
2.001569068 1,524,714 dTLB-store-misses
2.001569068 86,710 iTLB-load-misses
3.002516807 14,502,850 dTLB-load-misses
3.002516807 1,527,325 dTLB-store-misses
3.002516807 189,333 iTLB-load-misses
4.003480550 27,343,138 dTLB-load-misses
4.003480550 1,542,708 dTLB-store-misses
4.003480550 118,987 iTLB-load-misses
After recompiling the kernel with transparent hugepages and enabling
them:
root@vadelma:~# perf stat -I 1000 -e
dTLB-load-misses,dTLB-store-misses,iTLB-load-misses -a
# time counts unit events
1.000446250 6,559,299 dTLB-load-misses
1.000446250 78,022 dTLB-store-misses
1.000446250 615,533 iTLB-load-misses
2.001771713 7,980,471 dTLB-load-misses
2.001771713 172,949 dTLB-store-misses
2.001771713 837,294 iTLB-load-misses
3.002796124 6,795,584 dTLB-load-misses
3.002796124 84,586 dTLB-store-misses
3.002796124 760,424 iTLB-load-misses
Average TLB misses are down about 2/3 while IPC is slightly up, by
8-10%.
I'm perfectly fine if it's disabled by default, but it would be nice to
not have to recompile the kernel.
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https://bugs.launchpad.net/bugs/1933532
Title:
Large Page support disabled on Raspberry Pi kernels
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