From: Jakub Kicinski <kuba@kernel.org>
To: Shannon Nelson <shannon.nelson@amd.com>
Cc: <netdev@vger.kernel.org>, <davem@davemloft.net>,
<andrew+netdev@lunn.ch>, <edumazet@google.com>,
<pabeni@redhat.com>, <brett.creeley@amd.com>
Subject: Re: [PATCH net 2/2] pds_core: Add a retry mechanism when the adminq is full
Date: Wed, 29 Jan 2025 19:03:26 -0800 [thread overview]
Message-ID: <20250129190326.456680c8@kernel.org> (raw)
In-Reply-To: <20250129004337.36898-3-shannon.nelson@amd.com>
On Tue, 28 Jan 2025 16:43:37 -0800 Shannon Nelson wrote:
> If the adminq is full, the driver reports failure when trying to post
> new adminq commands. This is a bit aggressive and unexpected because
> technically the adminq post didn't fail in this case, it was just full.
> To harden this path add support for a bounded retry mechanism.
>
> It's possible some commands take longer than expected, maybe hundreds
> of milliseconds or seconds due to other processing on the device side,
> so to further reduce the chance of failure due to adminq full increase
> the PDS_CORE_DEVCMD_TIMEOUT from 5 to 10 seconds.
>
> The caller of pdsc_adminq_post() may still see -EAGAIN reported if the
> space in the adminq never freed up. In this case they can choose to
> call the function again or fail. For now, no callers will retry.
How about a semaphore? You can initialize it to the number of slots
in the queue, and use down_timeout() if you want the 10 sec timeout?
next prev parent reply other threads:[~2025-01-30 3:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-29 0:43 [PATCH net 0/2] pds_core: fixes for adminq overflow Shannon Nelson
2025-01-29 0:43 ` [PATCH net 1/2] pds_core: Prevent possible adminq overflow/stuck condition Shannon Nelson
2025-01-29 7:59 ` Michal Swiatkowski
2025-01-29 0:43 ` [PATCH net 2/2] pds_core: Add a retry mechanism when the adminq is full Shannon Nelson
2025-01-29 8:08 ` Michal Swiatkowski
2025-01-30 3:03 ` Jakub Kicinski [this message]
2025-01-31 19:25 ` Brett Creeley
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