From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54608) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7Xyr-0006J4-V2 for qemu-devel@nongnu.org; Thu, 08 Aug 2013 17:42:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V7Xyp-0006zr-KP for qemu-devel@nongnu.org; Thu, 08 Aug 2013 17:42:49 -0400 Received: from mail.avalus.com ([2001:41c8:10:1dd::10]:53785) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V7Xyp-0006xz-Es for qemu-devel@nongnu.org; Thu, 08 Aug 2013 17:42:47 -0400 From: Alex Bligh Date: Thu, 8 Aug 2013 22:42:02 +0100 Message-Id: <1375998147-24292-6-git-send-email-alex@alex.org.uk> In-Reply-To: <1375998147-24292-1-git-send-email-alex@alex.org.uk> References: <1375998147-24292-1-git-send-email-alex@alex.org.uk> Subject: [Qemu-devel] [RFC] [PATCHv8 05/30] aio / timers: Add prctl(PR_SET_TIMERSLACK, 1, ...) to reduce timer slack List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Anthony Liguori , Alex Bligh , liu ping fan , Stefan Hajnoczi , Paolo Bonzini , MORITA Kazutaka , rth@twiddle.net Where supported, called prctl(PR_SET_TIMERSLACK, 1, ...) to set one nanosecond timer slack to increase precision of timer calls. Signed-off-by: Alex Bligh --- qemu-timer.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/qemu-timer.c b/qemu-timer.c index 5e81935..9eb6db8 100644 --- a/qemu-timer.c +++ b/qemu-timer.c @@ -41,6 +41,10 @@ #include #endif +#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK +#include +#endif + /***********************************************************/ /* timers */ @@ -507,6 +511,9 @@ void init_clocks(void) vm_clock = qemu_clock_new(QEMU_CLOCK_VIRTUAL); host_clock = qemu_clock_new(QEMU_CLOCK_HOST); } +#ifdef CONFIG_PRCTL_PR_SET_TIMERSLACK + prctl(PR_SET_TIMERSLACK, 1, 0, 0, 0); +#endif } uint64_t qemu_timer_expire_time_ns(QEMUTimer *ts) -- 1.7.9.5