AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2024-12-25 19:05:18 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity

i40evf: Drop i40evf_fire_sw_int as it is prone to races

Browse Source 
Having the interrupts firing while we are polling causes extra overhead and
isn't needed for most systems out there. If an interrupt is lost us
experiencing a 2s latency spike before recovering is still not acceptable
and masks the issue. We are better off just identifying systems that lose
interrupts and instead enable workarounds for those systems.

To that end I am dropping the code that was strobing the interrupts as
there is a narrow window where having them enabled can actually cause
race issues anyway where a few stray packets might get misses if the
interrupt is re-enabled and fires before we call napi_complete.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
This commit is contained in:
Alexander Duyck 2017-11-14 07:00:46 -05:00 committed by Jeff Kirsher
parent f23735aa45
commit a6cab7d7f9
1 changed files with 0 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
drivers/net/ethernet/intel/i40evf/i40evf_main.c
View File

@ -281,33 +281,6 @@ void i40evf_irq_enable_queues(struct i40evf_adapter *adapter, u32 mask)
}
}
/**
* i40evf_fire_sw_int - Generate SW interrupt for specified vectors
* @adapter: board private structure
* @mask: bitmap of vectors to trigger
**/
static void i40evf_fire_sw_int(struct i40evf_adapter *adapter, u32 mask)
{
struct i40e_hw *hw = &adapter->hw;
int i;
u32 dyn_ctl;
if (mask & 1) {
dyn_ctl = rd32(hw, I40E_VFINT_DYN_CTL01);
dyn_ctl |= I40E_VFINT_DYN_CTLN1_SWINT_TRIG_MASK |
I40E_VFINT_DYN_CTLN1_ITR_INDX_MASK;
wr32(hw, I40E_VFINT_DYN_CTL01, dyn_ctl);
}
for (i = 1; i < adapter->num_msix_vectors; i++) {
if (mask & BIT(i)) {
dyn_ctl = rd32(hw, I40E_VFINT_DYN_CTLN1(i - 1));
dyn_ctl |= I40E_VFINT_DYN_CTLN1_SWINT_TRIG_MASK |
I40E_VFINT_DYN_CTLN1_ITR_INDX_MASK;
wr32(hw, I40E_VFINT_DYN_CTLN1(i - 1), dyn_ctl);
}
}
}
/**
* i40evf_irq_enable - Enable default interrupt generation settings
* @adapter: board private structure
@ -1743,13 +1716,6 @@ static void i40evf_watchdog_task(struct work_struct *work)
if (adapter->state == __I40EVF_RUNNING)
i40evf_request_stats(adapter);
watchdog_done:
if (adapter->state == __I40EVF_RUNNING) {
i40evf_irq_enable_queues(adapter, ~0);
i40evf_fire_sw_int(adapter, 0xFF);
} else {
i40evf_fire_sw_int(adapter, 0x1);
}
clear_bit(__I40EVF_IN_CRITICAL_TASK, &adapter->crit_section);
restart_watchdog:
if (adapter->state == __I40EVF_REMOVE)