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Howlett" , ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, kernel-team@meta.com References: <20260706114320.1643046-1-usama.arif@linux.dev> <20260706114320.1643046-3-usama.arif@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Usama Arif In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: D294610000F X-Rspam-User: X-Stat-Signature: f8kihqnjzwfxbc77o8xgenirqmjz4hoh X-Rspamd-Server: rspam03 X-HE-Tag: 1783340617-665225 X-HE-Meta: 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 dHHieKpW 4uv5GK3ohc3m7mAzsafkOowb5oxDXw9SK4oT/r/p5K2fX8VdWxD9YeJIfdfahqmiWWMrnk8NBQOSNb6DW7KOP7YyKr3KZsRAZqYUy+RjzgyGRX63r+XlYlgTn6mDjadvxUy54+wZZoeko02smTqP0GyRNfNIsnTc0BVBQeFg+E/l/lfKjCo2vPvBfvXdpUjc53x3RM0NGPmM/dTO2CCQknbT7SI8Hq5XNsK/HP3kW2S2RvFz8/YCQqfhqkgSyya41uPjo2wKnuOSF75eImmzwvr9LgDA6mFLBlHjO1I6f98K/6EtWWW3Jj9qruvxNukhZuEjPFKoWZR+uCZbY6OA6TxwpD+I/DXfs7naqGmQOcBSTDwE= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 06/07/2026 13:01, Kiryl Shutsemau wrote: > On Mon, Jul 06, 2026 at 04:42:04AM -0700, Usama Arif wrote: >> When a swap entry is installed in a page table, the mm must be added >> to init_mm.mmlist so that swapoff can find and unuse its swap entries. >> This double-checked locking pattern is currently open-coded in >> try_to_unmap_one() and copy_nonpresent_pte(). >> >> Move it into mm_prepare_for_swap_entries() in mm/internal.h and convert >> both callers so it can be reused by upcoming PMD-level swap entry code >> paths that also need to register the mm with swapoff. >> >> copy_nonpresent_pte() previously inserted into &src_mm->mmlist rather >> than &init_mm.mmlist, but the insertion point is irrelevant, mmlist >> is a circular list and swapoff walks it entirely from init_mm.mmlist, >> so only membership matters, not position. >> >> Reviewed-by: Dev Jain >> Reviewed-by: Zi Yan >> Acked-by: David Hildenbrand (Arm) >> Signed-off-by: Usama Arif >> --- >> mm/internal.h | 10 ++++++++++ >> mm/memory.c | 9 +-------- >> mm/rmap.c | 7 +------ >> 3 files changed, 12 insertions(+), 14 deletions(-) >> >> diff --git a/mm/internal.h b/mm/internal.h >> index 430aa72a4575..0360648e5726 100644 >> --- a/mm/internal.h >> +++ b/mm/internal.h >> @@ -1955,4 +1955,14 @@ static inline int get_sysctl_max_map_count(void) >> bool may_expand_vm(struct mm_struct *mm, const vma_flags_t *vma_flags, >> unsigned long npages); >> >> +static inline void mm_prepare_for_swap_entries(struct mm_struct *mm) >> +{ >> + if (list_empty(&mm->mmlist)) { >> + spin_lock(&mmlist_lock); >> + if (list_empty(&mm->mmlist)) >> + list_add(&mm->mmlist, &init_mm.mmlist); > > The patch is fine, but the name of the field is awful. Seeing mmlist I > assumed it listed all mm_structs. It has to have "swap" somewhere in the > field name. > I can send a separate patch once this is replaced to replace mmlist with swap_mmlist if that sounds better? Thanks Usama