From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:51404) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hF3Na-0000Sq-8Q for qemu-devel@nongnu.org; Fri, 12 Apr 2019 17:06:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hF3NY-000588-DY for qemu-devel@nongnu.org; Fri, 12 Apr 2019 17:06:34 -0400 From: Artyom Tarasenko Date: Fri, 12 Apr 2019 23:06:17 +0200 Message-Id: <1555103178-21894-4-git-send-email-atar4qemu@gmail.com> In-Reply-To: <1555103178-21894-1-git-send-email-atar4qemu@gmail.com> References: <1555103178-21894-1-git-send-email-atar4qemu@gmail.com> Subject: [Qemu-devel] [PATCH 3/4] target/ppc: improve performance of large BAT invalidations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, hpoussin@reactos.org Cc: qemu-ppc@nongnu.org, Artyom Tarasenko , David Gibson 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 --- 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