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152d523e63
Move all our context switch SPR save and restore code into two helpers. We do a few optimisations: - Group all mfsprs and all mtsprs. In many cases an mtspr sets a scoreboarding bit that an mfspr waits on, so the current practise of mfspr A; mtspr A; mfpsr B; mtspr B is the worst scheduling we can do. - SPR writes are slow, so check that the value is changing before writing it. A context switch microbenchmark using yield(): http://ozlabs.org/~anton/junkcode/context_switch2.c ./context_switch2 --test=yield 0 0 shows an improvement of almost 10% on POWER8. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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| .. | ||
| boot | ||
| configs | ||
| crypto | ||
| include | ||
| kernel | ||
| kvm | ||
| lib | ||
| math-emu | ||
| mm | ||
| net | ||
| oprofile | ||
| perf | ||
| platforms | ||
| sysdev | ||
| xmon | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||
| relocs_check.sh | ||