From patchwork Fri Jun 28 18:50:53 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 255566 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id A28E22C0096 for ; Sat, 29 Jun 2013 04:55:21 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UsdpD-0004mx-1K; Fri, 28 Jun 2013 18:55:15 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1Usdp1-0004i1-O3 for kernel-team@lists.ubuntu.com; Fri, 28 Jun 2013 18:55:03 +0000 Received: from c-67-160-231-42.hsd1.ca.comcast.net ([67.160.231.42] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UsdmU-0007Xd-Mx; Fri, 28 Jun 2013 18:52:27 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1UsdmS-0006VA-KH; Fri, 28 Jun 2013 11:52:24 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 031/105] xen/events: Handle VIRQ_TIMER before any other hardirq in event loop. Date: Fri, 28 Jun 2013 11:50:53 -0700 Message-Id: <1372445527-24414-32-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1372445527-24414-1-git-send-email-kamal@canonical.com> References: <1372445527-24414-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Cc: Keir Fraser , Kamal Mostafa , Konrad Rzeszutek Wilk X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.8.13.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Keir Fraser commit bee980d9e9642e96351fa3ca9077b853ecf62f57 upstream. This avoids any other hardirq handler seeing a very stale jiffies value immediately after wakeup from a long idle period. The one observable symptom of this was a USB keyboard, with software keyboard repeat, which would always repeat a key immediately that it was pressed. This is due to the key press waking the guest, the key handler immediately runs, sees an old jiffies value, and then that jiffies value significantly updated, before the key is unpressed. Reviewed-by: David Vrabel Signed-off-by: Keir Fraser Signed-off-by: Konrad Rzeszutek Wilk [ luis: backported to 3.5: - replaced xen_ulong_t by unsigned long ] Signed-off-by: Luis Henriques Signed-off-by: Kamal Mostafa --- drivers/xen/events.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 8aa3867..7ae3821 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -1298,7 +1298,7 @@ static void __xen_evtchn_do_upcall(void) { int start_word_idx, start_bit_idx; int word_idx, bit_idx; - int i; + int i, irq; int cpu = get_cpu(); struct shared_info *s = HYPERVISOR_shared_info; struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); @@ -1306,6 +1306,8 @@ static void __xen_evtchn_do_upcall(void) do { unsigned long pending_words; + unsigned long pending_bits; + struct irq_desc *desc; vcpu_info->evtchn_upcall_pending = 0; @@ -1316,6 +1318,17 @@ static void __xen_evtchn_do_upcall(void) /* Clear master flag /before/ clearing selector flag. */ wmb(); #endif + if ((irq = per_cpu(virq_to_irq, cpu)[VIRQ_TIMER]) != -1) { + int evtchn = evtchn_from_irq(irq); + word_idx = evtchn / BITS_PER_LONG; + pending_bits = evtchn % BITS_PER_LONG; + if (active_evtchns(cpu, s, word_idx) & (1ULL << pending_bits)) { + desc = irq_to_desc(irq); + if (desc) + generic_handle_irq_desc(irq, desc); + } + } + pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0); start_word_idx = __this_cpu_read(current_word_idx); @@ -1324,7 +1337,6 @@ static void __xen_evtchn_do_upcall(void) word_idx = start_word_idx; for (i = 0; pending_words != 0; i++) { - unsigned long pending_bits; unsigned long words; words = MASK_LSBS(pending_words, word_idx); @@ -1353,8 +1365,7 @@ static void __xen_evtchn_do_upcall(void) do { unsigned long bits; - int port, irq; - struct irq_desc *desc; + int port; bits = MASK_LSBS(pending_bits, bit_idx);