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charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: CF28A40065 Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=c+KE7Nge; spf=pass (imf17.hostedemail.com: domain of yuzhao@google.com designates 209.85.217.54 as permitted sender) smtp.mailfrom=yuzhao@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-Stat-Signature: xpwnkmnqyct6oeont1yeiwijgyktkf9k X-HE-Tag: 1651307725-728582 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Apr 29, 2022 at 7:10 AM zhong jiang wrote: > > On 2022/4/7 11:15 =E4=B8=8A=E5=8D=88, Yu Zhao wrote: ... > > + while (!mm && mm_state->head !=3D &mm_list->fifo) { > > + mm =3D list_entry(mm_state->head, struct mm_struct, lru_g= en.list); > > + > > + mm_state->head =3D mm_state->head->next; > > + > > + /* full scan for those added after the last iteration */ > > + if (!mm_state->tail || mm_state->tail =3D=3D &mm->lru_gen= .list) { > > + mm_state->tail =3D mm_state->head; > > + walk->full_scan =3D true; > > + } > > + > > The full_scan seems to be alway true. because mm_state->tail points to > the first item in mm_list, hence the walker's > > condition mm_state->tail =3D=3D &mm->lru_gen.list alway equal. Am I miss= ing > something? mm_state->tail points to the first item *added after the last iteration*. If no new items, mm_state->tail parks at mm_list->fifo.