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([2001:a61:1335:3601:f121:69fe:935a:67bd]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3a1f5a4c5e1sm15564687f8f.89.2025.05.13.04.02.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 13 May 2025 04:02:43 -0700 (PDT) Message-ID: <3fa2cbc3-fe81-4364-96c1-b753c52ddc16@suse.com> Date: Tue, 13 May 2025 13:02:42 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] USB: core: add a memory pool to urb for host-controller private data To: David Wang <00107082@163.com>, Oliver Neukum Cc: mathias.nyman@intel.com, gregkh@linuxfoundation.org, stern@rowland.harvard.edu, surenb@google.com, kent.overstreet@linux.dev, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250512150724.4560-1-00107082@163.com> <20250513055447.5696-1-00107082@163.com> <48d5cae9-ff7c-4076-8b71-8c16bcf00443@suse.com> <4006cec4.794d.196c8be2fd1.Coremail.00107082@163.com> <3dd5e698.921f.196c90c33af.Coremail.00107082@163.com> Content-Language: en-US From: Oliver Neukum In-Reply-To: <3dd5e698.921f.196c90c33af.Coremail.00107082@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 13.05.25 11:49, David Wang wrote: > Hi, I have one question about mem flags. > If usb_submit_urb wants a memory in context of flags A, say GFP_ATOMIC, but I already have a memory alloc with flags B and its size > is big enough, is it safe to return this memory to usb_submit_urb which is in the context of flags A? Yes, that is perfectly safe. HTH Oliver