From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15708C00A5A for ; Wed, 18 Jan 2023 02:14:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229692AbjARCOE (ORCPT ); Tue, 17 Jan 2023 21:14:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229667AbjARCOA (ORCPT ); Tue, 17 Jan 2023 21:14:00 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D536E2C646 for ; Tue, 17 Jan 2023 18:13:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674007991; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=s6J/WHZNn/3SX2lLfl7aH2I2U9AvTu3J+4+/5IXf5mA=; b=Dz+6BHDhe47PkPXH1k0S8L6pxa8IrVxQ5pVW4b6OrMR5zofnUbgxgHztUCgicma47SKUjH ZFUmo1eIXqxuDHzl3wpv81iT8AOByHAdecOLvztdmf4IzF2VCXt/UAPHF4R0IdwaS+twUG qV8lM9xsx92RBIgS4gxIycSkPB9wWMs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-647-hsWh1o42M4-y1LeMONrO4g-1; Tue, 17 Jan 2023 21:13:06 -0500 X-MC-Unique: hsWh1o42M4-y1LeMONrO4g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A8DD22805582; Wed, 18 Jan 2023 02:13:05 +0000 (UTC) Received: from localhost (ovpn-13-29.pek2.redhat.com [10.72.13.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E67491121315; Wed, 18 Jan 2023 02:13:04 +0000 (UTC) Date: Wed, 18 Jan 2023 10:13:01 +0800 From: Baoquan He To: Lorenzo Stoakes Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, urezki@gmail.com, stephen.s.brennan@oracle.com, willy@infradead.org, akpm@linux-foundation.org, hch@infradead.org Subject: Re: [PATCH v3 2/7] mm/vmalloc.c: add flags to mark vm_map_ram area Message-ID: References: <20230113031921.64716-1-bhe@redhat.com> <20230113031921.64716-3-bhe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/16/23 at 12:23pm, Lorenzo Stoakes wrote: > On Fri, Jan 13, 2023 at 11:19:16AM +0800, Baoquan He wrote: > > Through vmalloc API, a virtual kernel area is reserved for physical > > address mapping. And vmap_area is used to track them, while vm_struct > > is allocated to associate with the vmap_area to store more information > > and passed out. > > > > However, area reserved via vm_map_ram() is an exception. It doesn't have > > vm_struct to associate with vmap_area. And we can't recognize the > > vmap_area with '->vm == NULL' as a vm_map_ram() area because the normal > > freeing path will set va->vm = NULL before unmapping, please see > > function remove_vm_area(). > > > > Meanwhile, there are two kinds of handling for vm_map_ram area. One is > > the whole vmap_area being reserved and mapped at one time through > > vm_map_area() interface; the other is the whole vmap_area with > > VMAP_BLOCK_SIZE size being reserved, while mapped into split regions > > with smaller size via vb_alloc(). > > > > To mark the area reserved through vm_map_ram(), add flags field into > > struct vmap_area. Bit 0 indicates this is vm_map_ram area created > > through vm_map_ram() interface, while bit 1 marks out the type of > > vm_map_ram area which makes use of vmap_block to manage split regions > > via vb_alloc/free(). > > > > This is a preparatoin for later use. > > > > Small typo here :) Good catch, will fix it. > > > Signed-off-by: Baoquan He > > --- > > include/linux/vmalloc.h | 1 + > > mm/vmalloc.c | 16 ++++++++++++---- > > 2 files changed, 13 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > > index 096d48aa3437..69250efa03d1 100644 > > --- a/include/linux/vmalloc.h > > +++ b/include/linux/vmalloc.h > > @@ -76,6 +76,7 @@ struct vmap_area { > > unsigned long subtree_max_size; /* in "free" tree */ > > struct vm_struct *vm; /* in "busy" tree */ > > }; > > + unsigned long flags; /* mark type of vm_map_ram area */ > > }; > > > > /* archs that select HAVE_ARCH_HUGE_VMAP should override one or more of these */ > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index d6ff058ef4d0..ab4825050b5c 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -1589,7 +1589,8 @@ preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) > > static struct vmap_area *alloc_vmap_area(unsigned long size, > > unsigned long align, > > unsigned long vstart, unsigned long vend, > > - int node, gfp_t gfp_mask) > > + int node, gfp_t gfp_mask, > > + unsigned long va_flags) > > { > > struct vmap_area *va; > > unsigned long freed; > > @@ -1635,6 +1636,7 @@ static struct vmap_area *alloc_vmap_area(unsigned long size, > > va->va_start = addr; > > va->va_end = addr + size; > > va->vm = NULL; > > + va->flags = va_flags; > > > > spin_lock(&vmap_area_lock); > > insert_vmap_area(va, &vmap_area_root, &vmap_area_list); > > @@ -1913,6 +1915,10 @@ static struct vmap_area *find_unlink_vmap_area(unsigned long addr) > > > > #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) > > > > +#define VMAP_RAM 0x1 /* indicates vm_map_ram area*/ > > +#define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/ > > +#define VMAP_FLAGS_MASK 0x3 > > + > > struct vmap_block_queue { > > spinlock_t lock; > > struct list_head free; > > @@ -1988,7 +1994,8 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) > > > > va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, > > VMALLOC_START, VMALLOC_END, > > - node, gfp_mask); > > + node, gfp_mask, > > + VMAP_RAM|VMAP_BLOCK); > > if (IS_ERR(va)) { > > kfree(vb); > > return ERR_CAST(va); > > @@ -2297,7 +2304,8 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) > > } else { > > struct vmap_area *va; > > va = alloc_vmap_area(size, PAGE_SIZE, > > - VMALLOC_START, VMALLOC_END, node, GFP_KERNEL); > > + VMALLOC_START, VMALLOC_END, > > + node, GFP_KERNEL, VMAP_RAM); > > if (IS_ERR(va)) > > return NULL; > > > > @@ -2537,7 +2545,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, > > if (!(flags & VM_NO_GUARD)) > > size += PAGE_SIZE; > > > > - va = alloc_vmap_area(size, align, start, end, node, gfp_mask); > > + va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0); > > if (IS_ERR(va)) { > > kfree(area); > > return NULL; > > -- > > 2.34.1 > > > > Other than that typo, > > Reviewed-by: Lorenzo Stoakes >