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Message-ID: <20111223132453.GF25286@andromeda.dapyr.net>
Date: Fri, 23 Dec 2011 09:24:53 -0400
From: Konrad Rzeszutek Wilk <konrad@...nok.org>
To: "Liu, Jinsong" <jinsong.liu@...el.com>
Cc: "konrad.wilk@...cle.com" <konrad.wilk@...cle.com>,
"Brown, Len" <len.brown@...el.com>,
"jeremy.fitzhardinge@...rix.com" <jeremy.fitzhardinge@...rix.com>,
"Jiang, Yunhong" <yunhong.jiang@...el.com>,
"Shan, Haitao" <haitao.shan@...el.com>,
Kernel development list <linux-kernel@...r.kernel.org>,
"Zhao, Yakui" <yakui.zhao@...el.com>,
"Luck, Tony" <tony.luck@...el.com>,
"Kleen, Andi" <andi.kleen@...el.com>,
"xen-devel@...ts.xensource.com" <xen-devel@...ts.xensource.com>
Subject: Re: [Xen-devel] [PATCH 10/10] Xen: update pcpu online/offline logic
On Fri, Dec 23, 2011 at 10:32:12AM +0000, Liu, Jinsong wrote:
> >From 1e59d2ec2ff93b42c86d18c7cc9432ca2172a795 Mon Sep 17 00:00:00 2001
> From: Liu Jinsong <jinsong.liu@...el.com>
> Date: Wed, 14 Dec 2011 21:06:11 +0800
> Subject: [PATCH 10/10] Xen: update pcpu online/offline logic
>
> This patch update pcpu online/offline logic.
Roll them in the patch you posted please.
>
> It closes cpu0's /sys/.../xen_pcpu0/online authority to user.
> It also simplifies pcpu sync by removing redundant logic.
>
> Signed-off-by: Liu, Jinsong <jinsong.liu@...el.com>
> Signed-off-by: Jiang, Yunhong <yunhong.jiang@...el.com>
> ---
> drivers/xen/pcpu.c | 71 ++++++++++++++--------------------------------------
> 1 files changed, 19 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c
> index 6d1a770..1d32784 100644
> --- a/drivers/xen/pcpu.c
> +++ b/drivers/xen/pcpu.c
> @@ -24,7 +24,6 @@ static RAW_NOTIFIER_HEAD(xen_pcpu_chain);
>
> struct xen_pcpus {
> struct list_head list;
> - int present;
> };
> static struct xen_pcpus xen_pcpus;
>
> @@ -189,9 +188,13 @@ static int pcpu_sysdev_init(struct pcpu *cpu)
> kfree(cpu);
> return -1;
> }
> - sysdev_create_file(&cpu->sysdev, &attr_online);
> sysdev_create_file(&cpu->sysdev, &attr_apic_id);
> sysdev_create_file(&cpu->sysdev, &attr_acpi_id);
> +
> + /* Not open cpu0 online access to user */
> + if (cpu->sysdev.id)
> + sysdev_create_file(&cpu->sysdev, &attr_online);
> +
> return 0;
> }
>
> @@ -239,17 +242,10 @@ static struct pcpu *init_pcpu(struct xenpf_pcpuinfo *info)
> return pcpu;
> }
>
> -#define PCPU_NO_CHANGE 0
> -#define PCPU_ADDED 1
> -#define PCPU_ONLINE_OFFLINE 2
> -#define PCPU_REMOVED 3
> /*
> * Caller should hold the pcpu lock
> - * < 0: Something wrong
> - * 0: No changes
> - * > 0: State changed
> */
> -static struct pcpu *_sync_pcpu(int cpu_num, int *max_id, int *result)
> +static int _sync_pcpu(int cpu_num, int *max_id)
> {
> struct pcpu *pcpu = NULL;
> struct xenpf_pcpuinfo *info;
> @@ -259,14 +255,12 @@ static struct pcpu *_sync_pcpu(int cpu_num, int *max_id, int *result)
> };
> int ret;
>
> - *result = -1;
> -
> info = &op.u.pcpu_info;
> info->xen_cpuid = cpu_num;
>
> ret = HYPERVISOR_dom0_op(&op);
> if (ret)
> - return NULL;
> + return -1;
>
> if (max_id)
> *max_id = op.u.pcpu_info.max_present;
> @@ -275,28 +269,24 @@ static struct pcpu *_sync_pcpu(int cpu_num, int *max_id, int *result)
>
> if (info->flags & XEN_PCPU_FLAGS_INVALID) {
> /* The pcpu has been removed */
> - *result = PCPU_NO_CHANGE;
> if (pcpu) {
> raw_notifier_call_chain(&xen_pcpu_chain,
> XEN_PCPU_REMOVE,
> (void *)(long)pcpu->xen_id);
> xen_pcpu_free(pcpu);
> - *result = PCPU_REMOVED;
> }
> - return NULL;
> + return 0;
> }
>
>
> if (!pcpu) {
> - *result = PCPU_ADDED;
> pcpu = init_pcpu(info);
> if (pcpu == NULL) {
> printk(KERN_WARNING "Failed to init pcpu %x\n",
> info->xen_cpuid);
> - *result = -1;
> + return -1;
> }
> } else {
> - *result = PCPU_NO_CHANGE;
> /*
> * Old PCPU is replaced with a new pcpu, this means
> * several virq is missed, will it happen?
> @@ -307,10 +297,10 @@ static struct pcpu *_sync_pcpu(int cpu_num, int *max_id, int *result)
> pcpu->apic_id = info->apic_id;
> pcpu->acpi_id = info->acpi_id;
> }
> - if (xen_pcpu_online_check(info, pcpu))
> - *result = PCPU_ONLINE_OFFLINE;
> + xen_pcpu_online_check(info, pcpu);
> }
> - return pcpu;
> +
> + return 0;
> }
>
> int xen_pcpu_index(uint32_t id, int is_acpiid)
> @@ -353,50 +343,27 @@ static int xen_sync_pcpus(void)
> /*
> * Boot cpu always have cpu_id 0 in xen
> */
> - int cpu_num = 0, max_id = 0, result = 0, present = 0;
> + int cpu_num = 0, max_id = 0, ret = 0;
> struct list_head *elem, *tmp;
> struct pcpu *pcpu;
>
> get_pcpu_lock();
>
> - while ((result >= 0) && (cpu_num <= max_id)) {
> - pcpu = _sync_pcpu(cpu_num, &max_id, &result);
> -
> - printk(KERN_DEBUG "sync cpu %x get result %x max_id %x\n",
> - cpu_num, result, max_id);
> -
> - switch (result) {
> - case PCPU_NO_CHANGE:
> - if (pcpu)
> - present++;
> - break;
> - case PCPU_ADDED:
> - case PCPU_ONLINE_OFFLINE:
> - present++;
> - case PCPU_REMOVED:
> - break;
> - default:
> - printk(KERN_WARNING "Failed to sync pcpu %x\n",
> - cpu_num);
> - break;
> -
> - }
> + while (!ret && (cpu_num <= max_id)) {
> + ret = _sync_pcpu(cpu_num, &max_id);
> cpu_num++;
> }
>
> - if (result < 0) {
> + if (ret < 0) {
> list_for_each_safe(elem, tmp, &xen_pcpus.list) {
> pcpu = list_entry(elem, struct pcpu, pcpu_list);
> xen_pcpu_free(pcpu);
> }
> - present = 0;
> }
>
> - xen_pcpus.present = present;
> -
> put_pcpu_lock();
>
> - return 0;
> + return ret;
> }
>
> static void xen_pcpu_dpc(struct work_struct *work)
> @@ -436,10 +403,10 @@ static int __init xen_pcpu_init(void)
> }
>
> INIT_LIST_HEAD(&xen_pcpus.list);
> - xen_pcpus.present = 0;
>
> xen_sync_pcpus();
> - if (xen_pcpus.present > 0)
> +
> + if (!list_empty(&xen_pcpus.list))
> err = bind_virq_to_irqhandler(VIRQ_PCPU_STATE,
> 0, xen_pcpu_interrupt, 0, "pcpu", NULL);
> if (err < 0)
> --
> 1.6.5.6
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@...ts.xensource.com
> http://lists.xensource.com/xen-devel
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