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charset="us-ascii" Content-ID: <065DF65F3017CB419EB6F1BFF7AFC9C9@namprd15.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: 6698c9f2-8457-412c-afbe-08d6e3bed3ac X-MS-Exchange-CrossTenant-originalarrivaltime: 28 May 2019 22:50:05.6683 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: guro@fb.com X-MS-Exchange-Transport-CrossTenantHeadersStamped: BYAPR15MB2743 X-OriginatorOrg: fb.com X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-05-28_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1905280143 X-FB-Internal: deliver Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 27, 2019 at 11:38:42AM +0200, Uladzislau Rezki (Sony) wrote: > Move the BUG_ON()/RB_EMPTY_NODE() check under unlink_va() > function, it means if an empty node gets freed it is a BUG > thus is considered as faulty behaviour. It's not exactly clear from the description, why it's better. Also, do we really need a BUG_ON() in either place? Isn't something like this better? diff --git a/mm/vmalloc.c b/mm/vmalloc.c index c42872ed82ac..2df0e86d6aff 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1118,7 +1118,8 @@ EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); =20 static void __free_vmap_area(struct vmap_area *va) { - BUG_ON(RB_EMPTY_NODE(&va->rb_node)); + if (WARN_ON_ONCE(RB_EMPTY_NODE(&va->rb_node))) + return; =20 /* * Remove from the busy tree/list. Thanks!