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[2620:137:e000::1:20]) by mx.google.com with ESMTP id o13-20020a170906974d00b0078d027ceb41si8265247ejy.857.2022.11.08.19.45.49; Tue, 08 Nov 2022 19:46:14 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=ZF0As17l; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230237AbiKIDg4 (ORCPT + 99 others); Tue, 8 Nov 2022 22:36:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229951AbiKIDgw (ORCPT ); Tue, 8 Nov 2022 22:36:52 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72CE795A9 for ; Tue, 8 Nov 2022 19:35:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667964952; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uW859jypzBpKXzbjl1mx0hv6onZwUPSyaCvGWArWZW8=; b=ZF0As17lkScA9u5l2A8ApEfgHGFKnj8U1uxCzTtHSeICX/auHc7TUHJ3x5T7QGMHUCYWVc 23gA24hWBcGb0s16r1bbgN2XXSRklg0AZIky/VFuzv0X/1qfU5ZXNh7z1Lh3pW7e04qGV3 JGjxaKDSCVR9TGijPquMbwtNUe3mEi4= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-416-ZXfcfR-FPzekEwE6Jmfx3w-1; Tue, 08 Nov 2022 22:35:51 -0500 X-MC-Unique: ZXfcfR-FPzekEwE6Jmfx3w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D9A628339CE; Wed, 9 Nov 2022 03:35:50 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (ovpn-12-86.pek2.redhat.com [10.72.12.86]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2D7AB10197; Wed, 9 Nov 2022 03:35:46 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, akpm@linux-foundation.org, stephen.s.brennan@oracle.com, urezki@gmail.com, hch@infradead.org, Baoquan He Subject: [PATCH RFC 2/3] mm/vmalloc.c: add flags to mark vm_map_ram area Date: Wed, 9 Nov 2022 11:35:33 +0800 Message-Id: <20221109033535.269229-3-bhe@redhat.com> In-Reply-To: <20221109033535.269229-1-bhe@redhat.com> References: <20221109033535.269229-1-bhe@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1748988670921134022?= X-GMAIL-MSGID: =?utf-8?q?1748988670921134022?= Through vmalloc API, a virtual kernel area is reserved for physical address mapping. And vmap_area is used to track them, and 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 simply recognize the vm_map_ram areas with '->vm == NULL' because the normal freeing path will set va->vm = NULL before unmapping, please see function remove_vm_area(). Meanwhile, there are two types of vm_map_ram area. One is the whole vmap_area being reserved and mapped at one time; the other is the whole vmap_area with VMAP_BLOCK_SIZE size being reserved, while mapped into split regions with smaller size several times. To mark the area reserved through vm_map_ram(), add flags into the union field of struct vmap_area to reuse the space since that union space is free anyway if it's vm_map_ram area. This is a preparatoin for later use. Signed-off-by: Baoquan He --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 17 ++++++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 096d48aa3437..b739a60b73da 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -75,6 +75,7 @@ struct vmap_area { union { 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 */ }; }; diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 5d3fd3e6fe09..41d82dc07e13 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1815,6 +1815,7 @@ static void free_vmap_area_noflush(struct vmap_area *va) spin_lock(&vmap_area_lock); unlink_va(va, &vmap_area_root); + va->flags = 0; spin_unlock(&vmap_area_lock); nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> @@ -1887,6 +1888,9 @@ struct vmap_area *find_vmap_area(unsigned long addr) #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) +#define VMAP_RAM 0x1 +#define VMAP_BLOCK 0x2 + struct vmap_block_queue { spinlock_t lock; struct list_head free; @@ -1967,6 +1971,9 @@ static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) kfree(vb); return ERR_CAST(va); } + spin_lock(&vmap_area_lock); + va->flags = VMAP_RAM|VMAP_BLOCK; + spin_unlock(&vmap_area_lock); vaddr = vmap_block_vaddr(va->va_start, 0); spin_lock_init(&vb->lock); @@ -2229,8 +2236,12 @@ void vm_unmap_ram(const void *mem, unsigned int count) return; } - va = find_vmap_area(addr); + spin_lock(&vmap_area_lock); + va = __find_vmap_area((unsigned long)addr, &vmap_area_root); BUG_ON(!va); + if (va) + va->flags &= ~VMAP_RAM; + spin_unlock(&vmap_area_lock); debug_check_no_locks_freed((void *)va->va_start, (va->va_end - va->va_start)); free_unmap_vmap_area(va); @@ -2269,6 +2280,10 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node) if (IS_ERR(va)) return NULL; + spin_lock(&vmap_area_lock); + va->flags = VMAP_RAM; + spin_unlock(&vmap_area_lock); + addr = va->va_start; mem = (void *)addr; }