From: Mathias Nyman <mathias.nyman@linux.intel.com>
To: David Wang <00107082@163.com>, Mathias Nyman <mathias.nyman@intel.com>
Cc: gregkh@linuxfoundation.org, oneukum@suse.com,
stern@rowland.harvard.edu, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 1/2] USB: core: add a memory pool to urb caching host-controller private data
Date: Wed, 21 May 2025 16:34:53 +0300 [thread overview]
Message-ID: <f22dd1b0-fe1a-49a4-931d-15d57589b03b@linux.intel.com> (raw)
In-Reply-To: <49228bf7.a1d1.196f303aa15.Coremail.00107082@163.com>
On 21.5.2025 16.23, David Wang wrote:
>> Won't this still allocate a lot of unnecessary memory for the roothub urbs?
>> i.e. the ones queued with rh_urb_enqueue(hcd, urb).
>> The host drivers don't use the urb->hcpriv of those URBs.
>>
> The mempool slot is alloced on demand when hcd request private data with its urb.
> If a urb is ever used by hcd and the hcd requests private data with it, a memory would be alloced
> and this memory will not be released until the urb is destroyed.
Ok, thanks for the clarification.
Roothubs URBs should be fine then.
Thanks
Mathias
next prev parent reply other threads:[~2025-05-21 13:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-17 8:38 [PATCH v3 1/2] USB: core: add a memory pool to urb caching host-controller private data David Wang
2025-05-21 10:32 ` Greg KH
2025-05-21 11:25 ` David Wang
2025-05-21 12:58 ` Greg KH
2025-05-21 13:36 ` David Wang
2025-05-21 12:59 ` Greg KH
2025-05-21 14:00 ` David Wang
2025-05-21 15:34 ` David Wang
2025-05-21 12:28 ` Mathias Nyman
2025-05-21 13:23 ` David Wang
2025-05-21 13:34 ` Mathias Nyman [this message]
-- strict thread matches above, loose matches on Subject: below --
2025-05-17 8:35 David Wang
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