target/ppc: improve performance of large BAT invalidations

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 <atar4qemu@gmail.com>
Message-Id: <1555103178-21894-4-git-send-email-atar4qemu@gmail.com>
Reviewed-by: Hervé Poussineau <hpoussin@reactos.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Artyom Tarasenko 2019-04-12 23:06:17 +02:00 committed by David Gibson
parent 6e8a65abbb
commit aaef873b13

View File

@ -1820,6 +1820,13 @@ 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) {