From nobody Sat Apr 4 02:09:10 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3F9A2DD60E for ; Sat, 21 Mar 2026 18:05:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774116353; cv=none; b=Hul8Ke2CKfV5SEZMJSGTXsdTWUQxegSViypuvG4v9RwHfp5ls40CSdU/MSnQE7cE8WNR60QpdP0nAfxgO80SzBPik4bu0Wmq4xl8F2wykEAGa35rda5UT4PmTFtEPh0FjB3dSUxvb5qgBcdyCqnANQHAgawmIPX8m1fshfqxwGw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774116353; c=relaxed/simple; bh=1q9ZbSRou3kZy0bVZall4fchWN5XHmjqwgrNK0kmHD4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fbqlLttUjKtftz89QnA1PmEGY9xVUX6BVBmqeHF+X9ODJ8uX2XjXRGNlVIwQfpaExqEp3z8vvuz/PW8/+mZ4mQgxEeN2FdtGQCUVq2j7pQNeZfS7rH5WtrX94ToGgmLNlNzr0CpRVDZ0d9f60wHicHSDMUIwVcve3m+m2UGmWJ8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ifXqZ9gr; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ifXqZ9gr" Received: by smtp.kernel.org (Postfix) with ESMTPS id 5D6CDC2BCB0; Sat, 21 Mar 2026 18:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774116353; bh=1q9ZbSRou3kZy0bVZall4fchWN5XHmjqwgrNK0kmHD4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=ifXqZ9gr79xAqOtFHJ4E7O9+UUMY0J/I3p+9nrsAG3x/hBN4w8qnSbHgch4uT1uBK ozj7t0A2GRZctnTRusqFMZ/kcw91HS/7faSwlvfx0EUWoftCoY05GhpHjyWbmI8SPr lQ4aeIXam8/af8fc3S8v67nUO3VJyk51Rz914cgGoV2M9QD9eHS7UUL2vpkJpbcAgH wGJd0HgIO9EHMh4x0c3jR5SRYUxA8rxxY3yRtSGgBwh7gDnuoqTIoEGPM1E3+fNLbw uasEGEa4LXl/V+cW3isZIfCK5vxUVZD8QLT5W0LVPyNmN1RYF+8L30bs1uyzzk9tNE 72T5MnnSnF3Sg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4DF2E109448B; Sat, 21 Mar 2026 18:05:53 +0000 (UTC) From: Shivam Kalra via B4 Relay Date: Sat, 21 Mar 2026 23:35:46 +0530 Subject: [PATCH v6 1/6] mm/vmalloc: extract vm_area_free_pages() helper from vfree() Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260321-vmalloc-shrink-v6-1-062ca7b7ceb2@zohomail.in> References: <20260321-vmalloc-shrink-v6-0-062ca7b7ceb2@zohomail.in> In-Reply-To: <20260321-vmalloc-shrink-v6-0-062ca7b7ceb2@zohomail.in> To: Andrew Morton , Uladzislau Rezki Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alice Ryhl , Danilo Krummrich , Shivam Kalra X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1774116351; l=2771; i=shivamkalra98@zohomail.in; s=20260212; h=from:subject:message-id; bh=H130FITdP+gd6htRVApNT365j03KxXWr+CTNaNFiPA4=; b=uGx5cc0zWuNS8y3W1NbEacOLTPyrdZLL7S5/yLfUTJOFkmM/1kItTiCIB2t76BpqeE1eGdUNi 7JwPlwnRLO9AA63cg4NH9GKVOC/IZDQd9zmjyQFsgPTc5ygKm5h5cf3 X-Developer-Key: i=shivamkalra98@zohomail.in; a=ed25519; pk=9Q+S1LD/xjbjL7bEaLIlwRADBwU/6LJq7lYm8LFrkQE= X-Endpoint-Received: by B4 Relay for shivamkalra98@zohomail.in/20260212 with auth_id=633 X-Original-From: Shivam Kalra Reply-To: shivamkalra98@zohomail.in From: Shivam Kalra Extract the page-freeing loop and NR_VMALLOC stat accounting from vfree() into a reusable vm_area_free_pages() helper. The helper operates on a range [start_idx, end_idx) of pages from a vm_struct, making it suitable for both full free (vfree) and partial free (upcoming vrealloc shrink). Freed page pointers in vm->pages[] are set to NULL to prevent stale references when the vm_struct outlives the free (as in vrealloc shrink). Reviewed-by: Alice Ryhl Signed-off-by: Shivam Kalra --- mm/vmalloc.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index c607307c657a..3977398e56e4 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3416,6 +3416,38 @@ void vfree_atomic(const void *addr) schedule_work(&p->wq); } =20 +/* + * vm_area_free_pages - free a range of pages from a vmalloc allocation + * @vm: the vm_struct containing the pages + * @start_idx: first page index to free (inclusive) + * @end_idx: last page index to free (exclusive) + * + * Free pages [start_idx, end_idx) updating NR_VMALLOC stat accounting. + * Freed vm->pages[] entries are set to NULL. + * Caller is responsible for unmapping (vunmap_range) and KASAN + * poisoning before calling this. + */ +static void vm_area_free_pages(struct vm_struct *vm, unsigned int start_id= x, + unsigned int end_idx) +{ + unsigned int i; + + for (i =3D start_idx; i < end_idx; i++) { + struct page *page =3D vm->pages[i]; + + BUG_ON(!page); + /* + * High-order allocs for huge vmallocs are split, so + * can be freed as an array of order-0 allocations + */ + if (!(vm->flags & VM_MAP_PUT_PAGES)) + mod_lruvec_page_state(page, NR_VMALLOC, -1); + __free_page(page); + vm->pages[i] =3D NULL; + cond_resched(); + } +} + /** * vfree - Release memory allocated by vmalloc() * @addr: Memory base address @@ -3436,7 +3468,6 @@ void vfree_atomic(const void *addr) void vfree(const void *addr) { struct vm_struct *vm; - int i; =20 if (unlikely(in_interrupt())) { vfree_atomic(addr); @@ -3459,19 +3490,7 @@ void vfree(const void *addr) =20 if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS)) vm_reset_perms(vm); - for (i =3D 0; i < vm->nr_pages; i++) { - struct page *page =3D vm->pages[i]; - - BUG_ON(!page); - /* - * High-order allocs for huge vmallocs are split, so - * can be freed as an array of order-0 allocations - */ - if (!(vm->flags & VM_MAP_PUT_PAGES)) - mod_lruvec_page_state(page, NR_VMALLOC, -1); - __free_page(page); - cond_resched(); - } + vm_area_free_pages(vm, 0, vm->nr_pages); kvfree(vm->pages); kfree(vm); } --=20 2.43.0