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b=Ce+yZbIhiq2cMKfLdkoXgLsyrCnReqnjN4Z0QFeNfmGjycBuAVXpzBoTCbIyEvUN7 TullcC/YkKK0Q/YQoAEK5obFvYdwQERmJD+Uwx4F7NtpNKWGjEUCKUc79VEYJi2Kav 4SfQO/lg0uo9LhA7grPmaT5JqsNum01LVNi/KScFCXMCb0bZSVtDeHFoyxvAlrZWrr uWVxT9XgVqOIzess0ZkuSknSIOzhN/H88f7JW9ZOKNoMOkDY2m9UdO6GCBVEPpKbxF q2XjQcTIewbHDYYuokViM7UbOIKPSwzan4OchotebltAV0O7qzCsodeuqUDPLhzWv4 uLFQ6rezfj3ng== Message-ID: Date: Fri, 28 Nov 2025 12:26:42 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] hugetlb: Add guard support To: Fushuai Wang Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, muchun.song@linux.dev, osalvador@suse.de, wangfushuai@baidu.com References: <9cb0a602-69ca-400f-890c-e9dd5b44f53b@kernel.org> <20251128112307.80237-1-fushuai.wang@linux.dev> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251128112307.80237-1-fushuai.wang@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: 64BC5180008 X-Stat-Signature: xbx14877dyhag4t6h3fbnkec44fp9duh X-HE-Tag: 1764329207-833953 X-HE-Meta: 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 p4OkJzo9 lV6LoYOtYzmAkxHc+dWEhu4Q3s6qtD7/MHkF/p/uU8WejY7+Z758w2LJhydHgfeEpwAJH5YneMONtFL6rf5jVH06smMDwfNuzw3FS/0ZDTwZXR78PPX8A8tDYsqY/Q0g35CxR4Y49jV40iFDiVPKXuKMV2xxBErxLMPAe4xJfLCkbmohOqwKrcRbWGTZ7isvLEGmTUFdzh7mAQI3AIkBoS5vjFIC1wo++TvTZmowA46Hd1pGR+cVmbmRYk+/mFtFc+xMT/0Eg1AET7xqfI2sx8RL+Mn5dSREV3CtG X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 11/28/25 12:23, Fushuai Wang wrote: >>> include/linux/hugetlb.h | 8 ++++++++ >>> 1 file changed, 8 insertions(+) >>> >>> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h >>> index 8e63e46b8e1f..f97cb2f123a3 100644 >>> --- a/include/linux/hugetlb.h >>> +++ b/include/linux/hugetlb.h >>> @@ -15,6 +15,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> struct ctl_table; >>> struct user_struct; >>> @@ -468,6 +469,13 @@ static inline void hugetlb_split(struct vm_area_struct *vma, unsigned long addr) >>> >>> #endif /* !CONFIG_HUGETLB_PAGE */ >>> >>> +DEFINE_GUARD(hugetlb_vma_read, struct vm_area_struct *, >>> + hugetlb_vma_lock_read(_T), hugetlb_vma_unlock_read(_T)) >>> + >>> +DEFINE_GUARD(hugetlb_vma_write, struct vm_area_struct *, >>> + hugetlb_vma_lock_write(_T), hugetlb_vma_unlock_write(_T)) >>> +DEFINE_GUARD_COND(hugetlb_vma_write, _try, hugetlb_vma_trylock_write(_T)) >> >> Do I understand correctly that the code you are introducing does not >> have any users? > > Yes, it is not used now, but it can be used in future development to simplify > the code. If there are complex hugetlb_vma locks in the current code, this can > also be used later to optimize them. Right, but we usually don't add dead code. So it should ideally be introduced with actual users. -- Cheers David