Performing a complete flush is ~ 100 times faster than flushing 256MiB of 4KiB pages. Set a limit of 1024 pages and perform a complete flush afterwards.
This patch significantly speeds up AIX 5.1 and NetBSD-ofppc. Signed-off-by: Artyom Tarasenko <atar4q...@gmail.com> --- target/ppc/mmu_helper.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c index 4a6be4d..d7eed3a 100644 --- a/target/ppc/mmu_helper.c +++ b/target/ppc/mmu_helper.c @@ -1809,6 +1809,13 @@ static inline void do_invalidate_BAT(CPUPPCState *env, target_ulong BATu, base = BATu & ~0x0001FFFF; end = base + mask + 0x00020000; + if (((end - base) >> TARGET_PAGE_BITS) > 1024) { + /* Flushing 1024 4K pages is slower than a complete flush */ + LOG_BATS("Flush all BATs\n"); + tlb_flush(CPU(cs)); + LOG_BATS("Flush done\n"); + return; + } LOG_BATS("Flush BAT from " TARGET_FMT_lx " to " TARGET_FMT_lx " (" TARGET_FMT_lx ")\n", base, end, mask); for (page = base; page != end; page += TARGET_PAGE_SIZE) { -- 2.7.2