On 2024/4/2 9:19, chenxiang (M) wrote:
在 2024/3/25 星期一 15:33, Yihang Li 写道:
driver inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9BBFQ CVE: NA
In the current interrupt reporting mode, each CQ entry reports an interrupt. However, when there are a large number of I/O completion interrupts, the following issue may occur:
[ 4682.678657][ C129] irq 134: nobody cared (try booting with the "irqpoll" option) [ 4682.686137][ C129] CPU: 129 PID: 2567 Comm: irq/134-hisi_sa Kdump: loaded Tainted: G OE 5.10.0 #1 [ 4682.696297][ C129] Hardware name: To be filled by O.E.M. KpxxxEVB 2P2T2N TB/To be filled by O.E.M., BIOS KpxxxEVB 2P2T2N TB 03/23/2023 [ 4682.708455][ C129] Call trace: [ 4682.711589][ C129] dump_backtrace+0x0/0x1e4 [ 4682.715934][ C129] show_stack+0x20/0x2c [ 4682.719933][ C129] dump_stack+0xd8/0x140 [ 4682.724017][ C129] __report_bad_irq+0x54/0x180 [ 4682.728625][ C129] note_interrupt+0x1ec/0x2f0 [ 4682.733143][ C129] handle_irq_event+0x118/0x1ac [ 4682.737834][ C129] handle_fasteoi_irq+0xc8/0x200 [ 4682.742613][ C129] __handle_domain_irq+0x84/0xf0 [ 4682.747391][ C129] gic_handle_irq+0x88/0x2c0 [ 4682.751822][ C129] el1_irq+0xbc/0x140 [ 4682.755648][ C129] _find_next_bit.constprop.0+0x20/0x94 [ 4682.761036][ C129] cpumask_next+0x24/0x30 [ 4682.765208][ C129] gic_ipi_send_mask+0x48/0x170 [ 4682.769900][ C129] __ipi_send_mask+0x34/0x110 [ 4682.775720][ C129] smp_cross_call+0x3c/0xcc [ 4682.780064][ C129] arch_send_call_function_single_ipi+0x38/0x44 [ 4682.786146][ C129] send_call_function_single_ipi+0xd0/0xe0 [ 4682.791794][ C129] generic_exec_single+0xb4/0x170 [ 4682.796659][ C129] smp_call_function_single_async+0x2c/0x40 [ 4682.802395][ C129] blk_mq_complete_request_remote.part.0+0xec/0x100 [ 4682.808822][ C129] blk_mq_complete_request+0x30/0x70 [ 4682.813950][ C129] scsi_mq_done+0x48/0xac [ 4682.818128][ C129] sas_scsi_task_done+0xb0/0x150 [libsas] [ 4682.823692][ C129] slot_complete_v3_hw+0x230/0x710 [hisi_sas_v3_hw] [ 4682.830120][ C129] cq_thread_v3_hw+0xbc/0x190 [hisi_sas_v3_hw] [ 4682.836114][ C129] irq_thread_fn+0x34/0xa4 [ 4682.840371][ C129] irq_thread+0xc4/0x130 [ 4682.844455][ C129] kthread+0x108/0x13c [ 4682.848365][ C129] ret_from_fork+0x10/0x18 [ 4682.852621][ C129] handlers: [ 4682.855577][ C129] [<00000000949e52bf>] cq_interrupt_v3_hw [hisi_sas_v3_hw] threaded [<000000005d8e3b68>] cq_thread_v3_hw [hisi_sas_v3_hw] [ 4682.868084][ C129] Disabling IRQ #134
When the IRQ management layer processes each hardware interrupt, if the return value of the interrupt handler is IRQ_WAKE_THREAD, it will wake up the handler thread for this interrupt action and set IRQTF_RUNTHREAD flag, wait for the interrupt handling thread to clear the IRQTF_RUNTHREAD flag after execution. Later in note_interrupt(), use irq_count to count hardware interrupts and irqs_unhandled to count interrupts for which no thread handler is responsible. When irq_count reaches 100000 and irqs_unhandled reaches 99000, irq will be disabled.
In the performance test scenario, I/O completion hardware interrupts are continuously and quickly generated. As a result, the interrupt processing thread is cyclically called in irq_thread() and does not exit, this affects the response of the interrupt thread to the hardware interrupt. Finally, the irq is disabled.
Therefore, default enable interrupt coalescing to reduce the generation of hardware interrupts, this helps interrupt processing threads to stop calling in irq_thread().
For interrupt coalescing, the count of CQ entries is set to 10, and the interrupt coalescing timeout period is set to 10us.
Does it have an impact on performance?
According to my test data, enabling interrupt coalescing has a 95%-105% impact in all scenarios. For the 4K read 32 scenario, the performance is improved by about 4% (1342k -> 1396k).
Signed-off-by: Yihang Li liyihang9@huawei.com Signed-off-by: Bing Xia xiabing12@h-partners.com
drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c index 30a3b748692d..f337dffdadef 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c @@ -630,9 +630,11 @@ static void init_reg_v3_hw(struct hisi_hba *hisi_hba) hisi_sas_write32(hisi_hba, TRANS_LOCK_ICT_TIME, 0x4A817C80); hisi_sas_write32(hisi_hba, HGC_SAS_TXFAIL_RETRY_CTRL, 0x108); hisi_sas_write32(hisi_hba, CFG_AGING_TIME, 0x1);
- hisi_sas_write32(hisi_hba, INT_COAL_EN, 0x1);
- hisi_sas_write32(hisi_hba, OQ_INT_COAL_TIME, 0x1);
- hisi_sas_write32(hisi_hba, OQ_INT_COAL_CNT, 0x1);
- hisi_sas_write32(hisi_hba, INT_COAL_EN, 0x3);
- /* configure the interrupt coalescing timeout period 10us */
- hisi_sas_write32(hisi_hba, OQ_INT_COAL_TIME, 0xa);
- /* configure the count of CQ entries 10 */
- hisi_sas_write32(hisi_hba, OQ_INT_COAL_CNT, 0xa); hisi_sas_write32(hisi_hba, CQ_INT_CONVERGE_EN, hisi_sas_intr_conv); hisi_sas_write32(hisi_hba, OQ_INT_SRC, 0xffff);
@@ -2771,11 +2773,11 @@ static void config_intr_coal_v3_hw(struct hisi_hba *hisi_hba) if (hisi_hba->intr_coal_ticks == 0 || hisi_hba->intr_coal_count == 0) {
hisi_sas_write32(hisi_hba, INT_COAL_EN, 0x1);hisi_sas_write32(hisi_hba, OQ_INT_COAL_TIME, 0x1);hisi_sas_write32(hisi_hba, OQ_INT_COAL_CNT, 0x1);
/* configure the interrupt coalescing timeout period 10us */hisi_sas_write32(hisi_hba, OQ_INT_COAL_TIME, 0xa);/* configure the count of CQ entries 10 */hisi_sas_write32(hisi_hba, OQ_INT_COAL_CNT, 0xa); } else {
hisi_sas_write32(hisi_hba, INT_COAL_EN, 0x3); hisi_sas_write32(hisi_hba, OQ_INT_COAL_TIME, hisi_hba->intr_coal_ticks); hisi_sas_write32(hisi_hba, OQ_INT_COAL_CNT,.