From nobody Wed Oct 12 13:49:39 2022 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4MnYtC3pHXz4fNtZ; Wed, 12 Oct 2022 13:49:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4MnYtC3FQWz42Xf; Wed, 12 Oct 2022 13:49:39 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1665582579; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=nJCik2wmlsv9rJpRTCa7Sm9IifTXWJ1LcHVViezhqpY=; b=tnPXASETG2Rb9kkA+LK0QdZZ0dKs8ipZmQ5/cFdB3mJSAQQBrM24q6xr+nV9adE6LYPutb OUq6ia6CIARz6QB7hIKO/efTaee/my7yABGXM7lJQvxGSaB2CFvxUsaWdYhMssdtlvl/GY 814S2R9rMXuCPzuJOkLP+E86ZinGgDvu7ynwStBM0u3yLVyzmrKBmhWlfCEtz+lI4EWu8r 5i+ARTg0XIRjButjhlPiEo2aEw87dufxzsvGrCMsW+hBNZtemBWLZRBkD4BwEnxD4GdIKH 4ynFvwiRKGMyuA2k575mO3A+n90dZ6sPjCIHKxM+sbGnZigE4lmGvZ4diM+GRg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4MnYtC2GXNz1KQR; Wed, 12 Oct 2022 13:49:39 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 29CDndVa082022; Wed, 12 Oct 2022 13:49:39 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 29CDndCW082021; Wed, 12 Oct 2022 13:49:39 GMT (envelope-from git) Date: Wed, 12 Oct 2022 13:49:39 GMT Message-Id: <202210121349.29CDndCW082021@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: 6094749a1a5d - stable/13 - vm_page: Fix a logic error in the handling of PQ_ACTIVE operations List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/13 X-Git-Reftype: branch X-Git-Commit: 6094749a1a5dafb8daf98deab23fc968070bc695 Auto-Submitted: auto-generated ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1665582579; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=nJCik2wmlsv9rJpRTCa7Sm9IifTXWJ1LcHVViezhqpY=; b=WFt3/XmKLCzYwzIJzA2o89OguWHZ8OQQJgew9tedDKVl2yKY3FWvwznkbd5oUM3KqO6Y2J YykdQHbWcOq7cM2KAUVyDoATYIHzj7wYFoKxX54Mu/FVGEr9GhpCVFvxUFzZ1RuKgaxAzQ F07/vL2vc9swEDPQ52aEFSK22owTOjxGA55hGfW9KNlFgoIQg3+rA0feVJQBzuTLlmvRLX y6DyyVpLCe4M+XGqXyHvRPSKaW3S5/8FkDf6yjipr99uVUgOTqvkOgfGIdsH25TBkiIOXY VVSUvPqA7oOSnD1TZhurDTqXu7e3VDv9TLmhgQFowNahjEDO2yrGiaPQviS7tA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1665582579; a=rsa-sha256; cv=none; b=d2wc6k7C616t0QvPm341tVsKEvCNsh5fnlfZV0bNhH8rIa4OGbJeqtNkNV9xiLpftmTgTK GPLLh0nj9iggnLJj8FAa+dscd81sieTpuk2VXTskRDIQ5XyMvIM+VGiZQRR2RcQQE5ZNTK BVPKaCpo/R+44/PlE6nmZ427jypxKYBfFca3BuihM0O7b1YeVrrQ+D1B7IH/RG1Iz3+uzT CoTjctjiIME4ra0KiY1KqpMfwnOfoVt2t0eiwOMtwUvg5wQL9flas96tat80Wt/a34PWAE RTJkjNmYerkzOqJ1sPqtgesmM4zzZ8Sy589TBi0e26TeX6dkE1+eadz0lGDfhQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N The branch stable/13 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=6094749a1a5dafb8daf98deab23fc968070bc695 commit 6094749a1a5dafb8daf98deab23fc968070bc695 Author: Mark Johnston AuthorDate: 2022-10-05 19:12:46 +0000 Commit: Mark Johnston CommitDate: 2022-10-12 13:49:25 +0000 vm_page: Fix a logic error in the handling of PQ_ACTIVE operations As an optimization, vm_page_activate() avoids requeuing a page that's already in the active queue. A page's location in the active queue is mostly unimportant. When a page is unwired and placed back in the page queues, vm_page_unwire() avoids moving pages out of PQ_ACTIVE to honour the request, the idea being that they're likely mapped and so will simply get bounced back in to PQ_ACTIVE during a queue scan. In both cases, if the page was logically in PQ_ACTIVE but had not yet been physically enqueued (i.e., the page is in a per-CPU batch), we would end up clearing PGA_REQUEUE from the page. Then, batch processing would ignore the page, so it would end up unwired and not in any queues. This can arise, for example, when a page is allocated and then vm_page_activate() is called multiple times in quick succession. The result is that the page is hidden from the page daemon, so while it will be freed when its VM object is destroyed, it cannot be reclaimed under memory pressure. Fix the bug: when checking if a page is in PQ_ACTIVE, only perform the optimization if the page is physically enqueued. PR: 256507 Fixes: f3f38e2580f1 ("Start implementing queue state updates using fcmpset loops.") Reviewed by: alc, kib Sponsored by: E-CARD Ltd. Sponsored by: Klara, Inc. (cherry picked from commit 2c9dc2384f85a4ccc44a79b349f4fb0253a2f254) --- sys/vm/vm_page.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c index 81b2f518aff2..2f00657531c2 100644 --- a/sys/vm/vm_page.c +++ b/sys/vm/vm_page.c @@ -4120,7 +4120,12 @@ vm_page_mvqueue(vm_page_t m, const uint8_t nqueue, const uint16_t nflag) if (nqueue == PQ_ACTIVE) new.act_count = max(old.act_count, ACT_INIT); if (old.queue == nqueue) { - if (nqueue != PQ_ACTIVE) + /* + * There is no need to requeue pages already in the + * active queue. + */ + if (nqueue != PQ_ACTIVE || + (old.flags & PGA_ENQUEUED) == 0) new.flags |= nflag; } else { new.flags |= nflag; @@ -4217,7 +4222,8 @@ vm_page_release_toq(vm_page_t m, uint8_t nqueue, const bool noreuse) * referenced and avoid any queue operations. */ new.flags &= ~PGA_QUEUE_OP_MASK; - if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE) + if (nflag != PGA_REQUEUE_HEAD && old.queue == PQ_ACTIVE && + (old.flags & PGA_ENQUEUED) != 0) new.flags |= PGA_REFERENCED; else { new.flags |= nflag;