From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Rybchenko <arybchenko@solarflare.com>
Subject: Re: [PATCH v7 6/7] eal: add failure handle mechanism for
 hotplug
Date: Mon, 9 Jul 2018 16:50:56 +0300
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Cc: <jblunck@infradead.org>, <shreyansh.jain@nxp.com>, <dev@dpdk.org>,
 <helin.zhang@intel.com>
To: Jeff Guo <jia.guo@intel.com>, <stephen@networkplumber.org>,
 <bruce.richardson@intel.com>, <ferruh.yigit@intel.com>,
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 <shaopeng.he@intel.com>, <bernard.iremonger@intel.com>,
 <arybchenko@solarflare.com>, <wenzhuo.lu@intel.com>
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On 09.07.2018 15:01, Jeff Guo wrote:
> This patch introduces a failure handle mechanism to handle device
> hotplug removal event.
>
> First it can register sigbus handler when enable device event monitor. Once
> sigbus error be captured, it will check the failure address and accordingly
> remap the invalid memory for the corresponding device. Besed on this
> mechanism, it could guaranty the application not crash when the device be
> hotplug out.
>
> Signed-off-by: Jeff Guo <jia.guo@intel.com>
> Acked-by: Shaopeng He <shaopeng.he@intel.com>
> ---
> v7->v6:
> delete some unused part.
> ---
>   lib/librte_eal/linuxapp/eal/eal_dev.c | 112 +++++++++++++++++++++++++++++++++-
>   1 file changed, 111 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linuxapp/eal/eal_dev.c
> index 1cf6aeb..0de3fb7 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_dev.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_dev.c
> @@ -4,6 +4,8 @@
>   
>   #include <string.h>
>   #include <unistd.h>
> +#include <fcntl.h>
> +#include <signal.h>
>   #include <sys/socket.h>
>   #include <linux/netlink.h>
>   
> @@ -14,6 +16,10 @@
>   #include <rte_malloc.h>
>   #include <rte_interrupts.h>
>   #include <rte_alarm.h>
> +#include <rte_bus.h>
> +#include <rte_eal.h>
> +#include <rte_spinlock.h>
> +#include <rte_errno.h>
>   
>   #include "eal_private.h"
>   
> @@ -23,6 +29,16 @@ static bool monitor_started;
>   #define EAL_UEV_MSG_LEN 4096
>   #define EAL_UEV_MSG_ELEM_LEN 128
>   
> +/*
> + * spinlock for device failure process, protect the bus and the device
> + * to avoid race condition.
> + */
> +static rte_spinlock_t dev_failure_lock = RTE_SPINLOCK_INITIALIZER;

Sorry, it is still too vague why the lock is required. It is just generic
words. Please, add details and describe circumstance when it is
required.