@@ -540,6 +540,11 @@ static void vnet_event(void *arg, int event)
}
if (err == 0)
break;
+ {
+ long stackdiff;
+ viodbg(DATA, "** vio:%llx, vio->lp:%llx, stack:%llx\n",
+ &vio, &vio->lp, &stackdiff);
+ }
viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
msgbuf.tag.type,
msgbuf.tag.stype,
2. the output
from the below output, we see a re-enter to vnet_event happend. the
vio-hardwre report 2 interrupt
for same packet/or msg( why?)
vio: ID[0] vnet_walk_rx start[00000009] end[00000008]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:842800:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:845000:800]
vio: ID[0] ** vio:fffff8003f9cafa8, vio->lp:fffff8003ebf0008,
stack:fffff8003f9cafa0 << same ldc vio
vio: ID[0] ** vio:fffff8003f9cafa8, vio->lp:fffff8003ebf0008,
stack:fffff8003f9ccc << with diffrent run stack
afa0
vio: ID[0] TAG [02:01:0042:0d4becc7]
vio: ID[0] TAG [02:01:0042:0d4becc7]
...........
vio: ID[0] vnet_walk_rx start[0000000a] end[00000009]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:845000:800]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:845000:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:847800:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:847800:800]
vio: ID[0] ** vio:fffff8003f9cb588, vio->lp:fffff8003ebf0008,
stack:fffff8003f9cb580
vio: ID[0] ** vio:fffff8003f9cb588, vio->lp:fffff8003ebf0008,
stack:fffff8003f9ccc
3. where need protection
the reason is :
static irqreturn_t ldc_rx(int irq, void *dev_id){
out:
spin_unlock_irqrestore(&lp->lock, flags);
<<
here run with out any lock
send_events(lp, event_mask);
4. the dirty fix, welcome fain grained lock implementation suggestion:
From f24f76cc7b9bba04fcbe0406d8a1ada959c0bc4a Mon Sep 17 00:00:00 2001
From: Yongli He <yongli.he@windriver.com>
Date: Wed, 23 Sep 2009 17:42:16 +0800
Subject: [PATCH] Sun ldom vnet driver dead lock
static irqreturn_t ldc_rx(int irq, void *dev_id){
...
out:
spin_unlock_irqrestore(&lp->lock, flags);
<< here run with out any lock
send_events(lp, event_mask);
//if 2 vnet attach to same vswitch, ldom
//will report 2 irq then lead to dead lock
//on the vio->lock or lp->lock
}
this version fix just serialize all the event.
Signed-off-by: Yongli He <heyongli@gmail.com>
---
arch/sparc64/kernel/ldc.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)
@@ -785,6 +785,8 @@ static void send_events(struct ldc_channel *lp,
unsigned int event_mask)
lp->cfg.event(lp->event_arg, LDC_EVENT_DATA_READY);
}
+static spinlock_t event_lock=__SPIN_LOCK_UNLOCKED("ldc_event lock");
+
static irqreturn_t ldc_rx(int irq, void *dev_id)
{