From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch 2/4] timerfd: Handle relative timers with CONFIG_TIME_LOW_RES proper Date: Thu, 14 Jan 2016 16:54:46 -0000 Message-ID: <20160114164159.354500742__5810.64882358095$1452790579$gmane$org@linutronix.de> References: <20160114163744.582215466@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Return-path: Content-Disposition: inline; filename=timerfd--Handle-relative-timers-with-CONFIG_TIME_LOW_RES-proper.patch Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: LKML Cc: Ingo Molnar , Peter Zijlstra , Helge Deller , John Stultz , linux-m68k@lists.linux-m68k.org, dhowells@redhat.com Helge reported that a relative timer can return a remaining time larger than the programmed relative time on parisc and other architectures which have CONFIG_TIME_LOW_RES set. This happens because we add a jiffie to the resulting expiry time to prevent short timeouts. Use the new function hrtimer_expires_remaining_adjusted() to calculate the remaining time. It takes that extra added time into account for relative timers. Reported-by: Helge Deller Signed-off-by: Thomas Gleixner --- fs/timerfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/timerfd.c +++ b/fs/timerfd.c @@ -153,7 +153,7 @@ static ktime_t timerfd_get_remaining(str if (isalarm(ctx)) remaining = alarm_expires_remaining(&ctx->t.alarm); else - remaining = hrtimer_expires_remaining(&ctx->t.tmr); + remaining = hrtimer_expires_remaining_adjusted(&ctx->t.tmr); return remaining.tv64 < 0 ? ktime_set(0, 0): remaining; }