Date: Wed, 3 Jul 2019 18:46:39 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r349671 - head/sys/vm Message-ID: <201907031846.x63IkdBZ040503@repo.freebsd.org>
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Author: markj Date: Wed Jul 3 18:46:39 2019 New Revision: 349671 URL: https://svnweb.freebsd.org/changeset/base/349671 Log: Cache the next queue element when traversing a page queue. When QUEUE_MACRO_DEBUG_TRASH is configured, removing a queue element invalidates its queue linkage pointers. vm_pageout_collect_batch() was relying on these pointers remaining valid after a removal, so modify it to fetch the next queued page before dequeuing the current page. Submitted by: Don Morris <dgmorris@earthlink.net> Reviewed by: cem, vangyzen MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20842 Modified: head/sys/vm/vm_pageout.c Modified: head/sys/vm/vm_pageout.c ============================================================================== --- head/sys/vm/vm_pageout.c Wed Jul 3 18:29:18 2019 (r349670) +++ head/sys/vm/vm_pageout.c Wed Jul 3 18:46:39 2019 (r349671) @@ -266,7 +266,7 @@ static __always_inline void vm_pageout_collect_batch(struct scan_state *ss, const bool dequeue) { struct vm_pagequeue *pq; - vm_page_t m, marker; + vm_page_t m, marker, n; marker = ss->marker; pq = ss->pq; @@ -277,7 +277,8 @@ vm_pageout_collect_batch(struct scan_state *ss, const vm_pagequeue_lock(pq); for (m = TAILQ_NEXT(marker, plinks.q); m != NULL && ss->scanned < ss->maxscan && ss->bq.bq_cnt < VM_BATCHQUEUE_SIZE; - m = TAILQ_NEXT(m, plinks.q), ss->scanned++) { + m = n, ss->scanned++) { + n = TAILQ_NEXT(m, plinks.q); if ((m->flags & PG_MARKER) == 0) { KASSERT((m->aflags & PGA_ENQUEUED) != 0, ("page %p not enqueued", m));
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