Author: baggins Date: Fri Mar 9 21:39:07 2012 GMT Module: packages Tag: HEAD ---- Log message: - rel 2 - two small fixes for xen dom0
---- Files affected: packages/kernel: kernel-small_fixes.patch (1.54 -> 1.55) , kernel.spec (1.1025 -> 1.1026) ---- Diffs: ================================================================ Index: packages/kernel/kernel-small_fixes.patch diff -u packages/kernel/kernel-small_fixes.patch:1.54 packages/kernel/kernel-small_fixes.patch:1.55 --- packages/kernel/kernel-small_fixes.patch:1.54 Mon Feb 20 23:54:19 2012 +++ packages/kernel/kernel-small_fixes.patch Fri Mar 9 22:39:02 2012 @@ -144,3 +144,141 @@ +From: Konrad Rzeszutek Wilk <[email protected]> +To: [email protected], [email protected] +Subject: [PATCH] small fixes to 3.3 (and 3.2) CPU hotplug code. (v1) +Date: Wed, 1 Feb 2012 16:16:38 -0500 + +While I was playing with 'xm vcpu-set X N' I realized that the VCPU hotplug +code in 3.2 spews tons of messages. Found out that we were missing an preempt_* +call. While at it, I fixed also an annoying message ("XENBUS: Unable to ..") +that shows up during bootup. + +Anyhow, these are going for 3.3 and CC-ing stable on the: + [PATCH 1/2] xen/smp: Fix CPU online/offline bug triggering a BUG: + +-- +To unsubscribe from this list: send the line "unsubscribe linux-kernel" in +the body of a message to [email protected] +More majordomo info at http://vger.kernel.org/majordomo-info.html +Please read the FAQ at http://www.tux.org/lkml/ + +From: Konrad Rzeszutek Wilk <[email protected]> +To: [email protected], [email protected] +Subject: [PATCH 1/2] xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while atomic. +Date: Wed, 1 Feb 2012 16:16:39 -0500 + +When a user offlines a VCPU and then onlines it, we get: + +NMI watchdog disabled (cpu2): hardware events not enabled +BUG: scheduling while atomic: swapper/2/0/0x00000002 +Modules linked in: dm_multipath dm_mod xen_evtchn iscsi_boot_sysfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi scsi_mod libcrc32c crc32c radeon fbco + ttm bitblit softcursor drm_kms_helper xen_blkfront xen_netfront xen_fbfront fb_sys_fops sysimgblt sysfillrect syscopyarea xen_kbdfront xenfs [last unloaded: + +Pid: 0, comm: swapper/2 Tainted: G O 3.2.0phase15.1-00003-gd6f7f5b-dirty #4 +Call Trace: + [<ffffffff81070571>] __schedule_bug+0x61/0x70 + [<ffffffff8158eb78>] __schedule+0x798/0x850 + [<ffffffff8158ed6a>] schedule+0x3a/0x50 + [<ffffffff810349be>] cpu_idle+0xbe/0xe0 + [<ffffffff81583599>] cpu_bringup_and_idle+0xe/0x10 + +The reason for this should be obvious from this call-chain: +cpu_bringup_and_idle: + \- cpu_bringup + | \-[preempt_disable] + | + |- cpu_idle + \- play_dead [assuming the user offlined the VCPU] + | \ + | +- (xen_play_dead) + | \- HYPERVISOR_VCPU_off [so VCPU is dead, once user + | | onlines it starts from here] + | \- cpu_bringup [preempt_disable] + | + +- preempt_enable_no_reschedule() + +- schedule() + \- preempt_enable() + +So we have two preempt_disble() and one preempt_enable(). Calling +preempt_enable() after the cpu_bringup() in the xen_play_dead +fixes the imbalance. + +Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> +--- + arch/x86/xen/smp.c | 7 +++++++ + 1 files changed, 7 insertions(+), 0 deletions(-) + +diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c +index 041d4fe..501d4e0 100644 +--- a/arch/x86/xen/smp.c ++++ b/arch/x86/xen/smp.c +@@ -409,6 +409,13 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */ + play_dead_common(); + HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL); + cpu_bringup(); ++ /* ++ * Balance out the preempt calls - as we are running in cpu_idle ++ * loop which has been called at bootup from cpu_bringup_and_idle. ++ * The cpucpu_bringup_and_idle called cpu_bringup which made a ++ * preempt_disable() So this preempt_enable will balance it out. ++ */ ++ preempt_enable(); + } + + #else /* !CONFIG_HOTPLUG_CPU */ +-- +1.7.7.5 + +-- +To unsubscribe from this list: send the line "unsubscribe linux-kernel" in +the body of a message to [email protected] +More majordomo info at http://vger.kernel.org/majordomo-info.html +Please read the FAQ at http://www.tux.org/lkml/ + +From: Konrad Rzeszutek Wilk <[email protected]> +To: [email protected], [email protected] +Subject: [PATCH 2/2] xen/bootup: During bootup suppress XENBUS: Unable to read cpu state +Date: Wed, 1 Feb 2012 16:16:40 -0500 + +When the initial domain starts, it prints (depending on the +amount of CPUs) a slew of +XENBUS: Unable to read cpu state +XENBUS: Unable to read cpu state +XENBUS: Unable to read cpu state +XENBUS: Unable to read cpu state + +which provide no useful information - as the error is a valid +issue - but not on the initial domain. The reason is that the +XenStore is not accessible at that time (it is after all the +first guest) so the CPU hotplug watch cannot parse "availability/cpu" +attribute. + +Signed-off-by: Konrad Rzeszutek Wilk <[email protected]> +--- + drivers/xen/cpu_hotplug.c | 3 ++- + 1 files changed, 2 insertions(+), 1 deletions(-) + +diff --git a/drivers/xen/cpu_hotplug.c b/drivers/xen/cpu_hotplug.c +index 14e2d99..4dcfced 100644 +--- a/drivers/xen/cpu_hotplug.c ++++ b/drivers/xen/cpu_hotplug.c +@@ -30,7 +30,8 @@ static int vcpu_online(unsigned int cpu) + sprintf(dir, "cpu/%u", cpu); + err = xenbus_scanf(XBT_NIL, dir, "availability", "%s", state); + if (err != 1) { +- printk(KERN_ERR "XENBUS: Unable to read cpu state\n"); ++ if (!xen_initial_domain()) ++ printk(KERN_ERR "XENBUS: Unable to read cpu state\n"); + return err; + } + +-- +1.7.7.5 + +-- +To unsubscribe from this list: send the line "unsubscribe linux-kernel" in +the body of a message to [email protected] +More majordomo info at http://vger.kernel.org/majordomo-info.html +Please read the FAQ at http://www.tux.org/lkml/ + ================================================================ Index: packages/kernel/kernel.spec diff -u packages/kernel/kernel.spec:1.1025 packages/kernel/kernel.spec:1.1026 --- packages/kernel/kernel.spec:1.1025 Thu Mar 1 09:29:41 2012 +++ packages/kernel/kernel.spec Fri Mar 9 22:39:02 2012 @@ -91,7 +91,7 @@ %define have_pcmcia 0 %endif -%define rel 1 +%define rel 2 %define basever 3.2 %define postver .9 @@ -1515,6 +1515,10 @@ All persons listed below can be reached at <cvs_login>@pld-linux.org $Log$ +Revision 1.1026 2012/03/09 21:39:02 baggins +- rel 2 +- two small fixes for xen dom0 + Revision 1.1025 2012/03/01 08:29:41 arekm - up to 3.2.9 ================================================================ ---- CVS-web: http://cvs.pld-linux.org/cgi-bin/cvsweb.cgi/packages/kernel/kernel-small_fixes.patch?r1=1.54&r2=1.55&f=u http://cvs.pld-linux.org/cgi-bin/cvsweb.cgi/packages/kernel/kernel.spec?r1=1.1025&r2=1.1026&f=u _______________________________________________ pld-cvs-commit mailing list [email protected] http://lists.pld-linux.org/mailman/listinfo/pld-cvs-commit
