From nobody Mon Oct 20 17:54:10 2025 X-Original-To: dev-commits-src-branches@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 4cr32q3s9Nz6CrHW; Mon, 20 Oct 2025 17:54:11 +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 "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4cr32q0wjVz3xSh; Mon, 20 Oct 2025 17:54:11 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1760982851; 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=wtk6RMHAfqah/faIep1iIgdYE0WFxeD5lyFoq9nxRks=; b=a15sJw24PN0zRuzLHE2EjjFLSPLyiVklJqPvdQ/PqvAeSDv43WSVRRGBBvUEe85RDdcSTP VxGo5k7bny0yJvIinqI+WMRdNvRlGErvjqhpwWCkrN1cszXJHmP4P/qqOlyBcr5QkxA7MX MquvmnTBHYze7D9io/zbnoA19rjlsYUYl11HqBmZgRjhT6GZKvpwwr+zAMMC9Dh70oq8Gm EDRH8mUgUiFReNltOfbovKcTSy29sS0tgbzB9Ckw4M4dyHRhTLR4FBu4TGGBXQW48w5oG3 0g45y+u792woTF780hMXM8yB/MYDsZWz3QUzI9B6ZCL8aJE/XM8tVWfXMKrNVQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1760982851; 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=wtk6RMHAfqah/faIep1iIgdYE0WFxeD5lyFoq9nxRks=; b=St7EjMV31AqTejxcSvHiWN+HI9q8qBZIhoEczWRu70KH3ejMVkDusVkNtYaagbjKsM6Ke3 FqJPDvNs2fNMQqtE6su8HnIzoT4UVsZn+5EO9He/XvuyX5qVaL2CbuAFBmdrP3xAq77hpU hsRo0NhKoWwHaoMnVoKTImki4EziXnJjpRzSQsxfKPkidKlZ/71ssHtpjKNYXrf+9iOdo1 C1Vc+XIww/OFUo/49uVegYcllcenEstyukVLUbwtTOSlUXrbwipFDkyN63sdHxEsIITDBF 6xgNGpKtm2y1WPdK6DXIw2yYMJSdhxQGgYNMom2s/8of39j35mj52/fwpiADzw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1760982851; a=rsa-sha256; cv=none; b=dKbV4Gk1P++lwjvO44ePOvgdXV2M9rC6HPemsfolAiVGtMs04V5NzCsHE9h9l+xd+n0X6b 7rBfRZEiruQoi1+OpDy6nCXm0XLhqvQQ6CMtOC99W4BLgBFlEARthqW7yjxIKFwmAckpZq +Hrd0dwzPlpNGipU1V8GviAYYJfgkSDUb1vzhzOMyjguOMIgJBhhbx5VilvFKXfkwquUbx svhL0t6DxjRzBNMCcrtbW+MOot8/vOkqsoU+l//nVoO9PO65m2qGPJL3P11Dv0EbPw9VAX nHzunJOqZypuXH7f6+9mFQ39SP/felxO/YRInEsW/6/dHPnMFrL+4cmTlUyoQg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none 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 4cr32q0T3Vz7mC; Mon, 20 Oct 2025 17:54:11 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 59KHsAuX030887; Mon, 20 Oct 2025 17:54:10 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 59KHsAeR030884; Mon, 20 Oct 2025 17:54:10 GMT (envelope-from git) Date: Mon, 20 Oct 2025 17:54:10 GMT Message-Id: <202510201754.59KHsAeR030884@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: d7226d1858c1 - stable/15 - vm_domainset: Ensure round-robin works properly List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@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/15 X-Git-Reftype: branch X-Git-Commit: d7226d1858c188475b12b0c4dff5bc794e42be6d Auto-Submitted: auto-generated The branch stable/15 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=d7226d1858c188475b12b0c4dff5bc794e42be6d commit d7226d1858c188475b12b0c4dff5bc794e42be6d Author: Olivier Certner AuthorDate: 2025-09-25 14:40:30 +0000 Commit: Mark Johnston CommitDate: 2025-10-20 16:47:37 +0000 vm_domainset: Ensure round-robin works properly All iterators that rely on an object's 'struct domainset_ref' (field 'domain' on 'struct vm_object'), which is the case for page allocations with objects, are used with the corresponding object locked for writing, so cannot lose concurrent iterator index's increases even if those are made without atomic operations. The only offender was thread stack allocation, which has just been fixed in commit 3b9b64457676 ("vm: Fix iterator usage in vm_thread_stack_create()"). However, the interleaved policy would still reset the iterator index when restarting, losing track of the next domain to allocate from when applying round-robin, which all allocation policies do if allocation from the first domain fails. Fix this last round-robin problem by not resetting the shared index at iterator's phase init on DOMAINSET_POLICY_INTERLEAVE. Add an assertion to check that, when passed, an object is write-locked in order to prevent the problem mentioned in the first paragraph from reappearing. Reviewed by: markj MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D52733 (cherry picked from commit 7b0fe2d405ae09b1247bccc6fa45a6d2755cbe4c) --- sys/vm/vm_domainset.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/sys/vm/vm_domainset.c b/sys/vm/vm_domainset.c index 9fa17da954f7..c25ed0cc2267 100644 --- a/sys/vm/vm_domainset.c +++ b/sys/vm/vm_domainset.c @@ -113,7 +113,6 @@ vm_domainset_iter_interleave(struct vm_domainset_iter *di, int *domain) int d; d = di->di_offset % di->di_domain->ds_cnt; - *di->di_iter = d; *domain = di->di_domain->ds_order[d]; } @@ -260,9 +259,14 @@ vm_domainset_iter_page_init(struct vm_domainset_iter *di, struct vm_object *obj, * are immutable and unsynchronized. Updates can race but pointer * loads are assumed to be atomic. */ - if (obj != NULL && obj->domain.dr_policy != NULL) + if (obj != NULL && obj->domain.dr_policy != NULL) { + /* + * This write lock protects non-atomic increments of the + * iterator index in vm_domainset_iter_rr(). + */ + VM_OBJECT_ASSERT_WLOCKED(obj); dr = &obj->domain; - else + } else dr = &curthread->td_domain; vm_domainset_iter_init(di, dr->dr_policy, &dr->dr_iter, obj, pindex);