From: Jakub Kicinski <kuba@kernel•org>
To: Shannon Nelson <shannon.nelson@amd•com>
Cc: <netdev@vger•kernel.org>, <davem@davemloft•net>,
<edumazet@google•com>, <pabeni@redhat•com>,
<brett.creeley@amd•com>, <drivers@pensando•io>
Subject: Re: [PATCH net-next 4/8] ionic: add work item for missed-doorbell check
Date: Wed, 12 Jun 2024 18:19:00 -0700 [thread overview]
Message-ID: <20240612181900.4d9d18d0@kernel.org> (raw)
In-Reply-To: <20240610230706.34883-5-shannon.nelson@amd.com>
On Mon, 10 Jun 2024 16:07:02 -0700 Shannon Nelson wrote:
> +static void ionic_napi_schedule_do_softirq(struct napi_struct *napi)
> +{
> + if (napi_schedule_prep(napi)) {
> + local_bh_disable();
> + __napi_schedule(napi);
> + local_bh_enable();
No need to open code napi_schedule()
local_bh_disable();
napi_schedule(napi);
local_bh_enable();
is a fairly well-established pattern
> + }
> +}
> +static void ionic_doorbell_check_dwork(struct work_struct *work)
> +{
> + struct ionic *ionic = container_of(work, struct ionic,
> + doorbell_check_dwork.work);
> + struct ionic_lif *lif = ionic->lif;
> +
> + if (test_bit(IONIC_LIF_F_FW_STOPPING, lif->state) ||
> + test_bit(IONIC_LIF_F_FW_RESET, lif->state))
> + return;
> +
> + mutex_lock(&lif->queue_lock);
This will deadlock under very inopportune circumstances, no?
The best way of implementing periodic checks using a workqueue is to
only cancel it sync from the .remove callback, before you free the
netdev. Otherwise cancel it non-sync or don't cancel at all, and once
it takes the lock double check the device is still actually running.
next prev parent reply other threads:[~2024-06-13 1:19 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-10 23:06 [PATCH net-next 0/8] ionic: rework fix for doorbell miss Shannon Nelson
2024-06-10 23:06 ` [PATCH net-next 1/8] ionic: remove missed doorbell per-queue timer Shannon Nelson
2024-06-10 23:07 ` [PATCH net-next 2/8] ionic: Keep interrupt affinity up to date Shannon Nelson
2024-06-10 23:07 ` [PATCH net-next 3/8] ionic: add private workqueue per-device Shannon Nelson
2024-06-13 1:08 ` Jakub Kicinski
2024-06-13 20:38 ` Nelson, Shannon
2024-06-13 22:19 ` Jakub Kicinski
2024-06-13 22:40 ` Nelson, Shannon
2024-06-10 23:07 ` [PATCH net-next 4/8] ionic: add work item for missed-doorbell check Shannon Nelson
2024-06-13 1:19 ` Jakub Kicinski [this message]
2024-06-13 20:38 ` Nelson, Shannon
2024-06-14 1:26 ` Przemek Kitszel
2024-06-10 23:07 ` [PATCH net-next 5/8] ionic: add per-queue napi_schedule for doorbell check Shannon Nelson
2024-06-10 23:07 ` [PATCH net-next 6/8] ionic: check for queue deadline in doorbell_napi_work Shannon Nelson
2024-06-10 23:07 ` [PATCH net-next 7/8] ionic: Use an u16 for rx_copybreak Shannon Nelson
2024-06-15 21:20 ` David Laight
2024-06-16 1:28 ` Andrew Lunn
2024-06-16 10:27 ` David Laight
2024-06-17 16:24 ` Brett Creeley
2024-06-18 8:16 ` David Laight
2024-06-18 16:11 ` Brett Creeley
2024-06-10 23:07 ` [PATCH net-next 8/8] ionic: Only run the doorbell workaround for certain asic_type Shannon Nelson
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