From nobody Sun Sep 14 20:13:21 2025 X-Original-To: dev-commits-src-main@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 4cPzr169SLz67PfW; Sun, 14 Sep 2025 20:13:21 +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 4cPzr12k5Jz3wht; Sun, 14 Sep 2025 20:13:21 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1757880801; 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=4D/f685krVi2Jzr319iqs9lbuxpGB1FTUDGM9mRC/h0=; b=fb/4a0O0tLLUGyE8n/l8uOI+cQ3RkC4+GAJCH8C2WA8Bzcshy4iYQP31r3+vIVQ0gaqvev j3KCPwu/uKb3GQG3iZX2I9/DNGrd4UHP8mdj15VZrnTIp5Sunfp+juMwV2FL3FG6qiq75+ iU/eY8A8w0dFRoPWwuj1edN51yefJkU9lPHjS7dox7r3iPbDTQtaJrlG11hsuNkxlzN7SG kZ8Btw8C2OblVhRKGV/Y6zLtnFLwJjjyXhHAzptwC67AcqCFvBHnbS2uC37J14xp8fyiZP YDf+yKAOmVhH5LkAwb78FEQ6UwbETAED2mJ2fF3N5Qs9xzzMYQtzAHY2z3EnMQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1757880801; 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=4D/f685krVi2Jzr319iqs9lbuxpGB1FTUDGM9mRC/h0=; b=n0KYR/xw2vllCZtn7P7DbbR9/eoyD6Ph041lBI9oOSy3bhd3eNUx4Wiz27FczcUyxzP8le E61bj5pfZAzAbMMMKu/BTePeh9p2A/p3kt07GDYoOoFL6qkmQxV8WsYwZANBz/iXM761oe fdaonS9jdrx7gk4f5hEBSmjE5H/0xW3Mab8RPAh6pJ1JIsgJ1JhiLWLKqCPSJWQN+QZ0K2 gr/k/yxh1bOFApqQup8D1L9Ba1znFC9+cS2IP4VuRnUlu/jud3HznTGqqI+Lj2NLcGMeee lsFEYrUpMJ9S/kMe3M99Q4+dcUlXEZX0fnwdqqutHgdyb1os9fmAHnUFyc0C9w== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1757880801; a=rsa-sha256; cv=none; b=FpeG9zLV1Sk8Y5kxhEJh2CxW+G1mUEDQ0NIDxwQHO96bXKYZVEcmVnoYcspShWRyupKw8N 3UKBWPlSGhnuZmeX39C9GY1/ptuF5g0OsepmJr94zon8f9SVNAY/NPeVxzSYjL6apjUuYu 4hK+S9nydkggniJRtk+3b8gyYVhgD9IKcdjsbHP5+a5UqIrFsCKppjFY5ZuWN/gGWC5B0F le9dNXFsfRXNWn0Uk+CY76xJnt3/kqE76mDfXzJYJpreBdR7t80feY9AzyHnN5+4OGUSSA HtNob/wUIHdVInaIlOhf4mfNg9gO2cmUwvModTXRfhJbMrg8hLuLlRNfUSg2vQ== 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 4cPzr12CzXz7mL; Sun, 14 Sep 2025 20:13:21 +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 58EKDLnt066060; Sun, 14 Sep 2025 20:13:21 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 58EKDLMF066057; Sun, 14 Sep 2025 20:13:21 GMT (envelope-from git) Date: Sun, 14 Sep 2025 20:13:21 GMT Message-Id: <202509142013.58EKDLMF066057@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: 5bd4c04a4e7f - main - vm_fault: add vm_fault_might_be_cow() helper List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 5bd4c04a4e7f7bda657e6027e64675d0caf50715 Auto-Submitted: auto-generated The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=5bd4c04a4e7f7bda657e6027e64675d0caf50715 commit 5bd4c04a4e7f7bda657e6027e64675d0caf50715 Author: Konstantin Belousov AuthorDate: 2025-08-14 03:39:05 +0000 Commit: Konstantin Belousov CommitDate: 2025-09-14 19:12:46 +0000 vm_fault: add vm_fault_might_be_cow() helper The helper checks that the object containing the fs->m page is not the top object in the shadow chain. Reviewed by: alc, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D51474 --- sys/vm/vm_fault.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/sys/vm/vm_fault.c b/sys/vm/vm_fault.c index a00134715171..226cf34b3ca4 100644 --- a/sys/vm/vm_fault.c +++ b/sys/vm/vm_fault.c @@ -258,6 +258,12 @@ vm_fault_unlock_vp(struct faultstate *fs) } } +static bool +vm_fault_might_be_cow(struct faultstate *fs) +{ + return (fs->object != fs->first_object); +} + static void vm_fault_deallocate(struct faultstate *fs) { @@ -265,7 +271,7 @@ vm_fault_deallocate(struct faultstate *fs) vm_fault_page_release(&fs->m_cow); vm_fault_page_release(&fs->m); vm_object_pip_wakeup(fs->object); - if (fs->object != fs->first_object) { + if (vm_fault_might_be_cow(fs)) { VM_OBJECT_WLOCK(fs->first_object); vm_fault_page_free(&fs->first_m); VM_OBJECT_WUNLOCK(fs->first_object); @@ -1005,7 +1011,7 @@ vm_fault_cow(struct faultstate *fs) { bool is_first_object_locked; - KASSERT(fs->object != fs->first_object, + KASSERT(vm_fault_might_be_cow(fs), ("source and target COW objects are identical")); /* @@ -1169,7 +1175,7 @@ vm_fault_zerofill(struct faultstate *fs) * If there's no object left, fill the page in the top * object with zeros. */ - if (fs->object != fs->first_object) { + if (vm_fault_might_be_cow(fs)) { vm_object_pip_wakeup(fs->object); fs->object = fs->first_object; fs->pindex = fs->first_pindex; @@ -1433,7 +1439,7 @@ vm_fault_busy_sleep(struct faultstate *fs, int allocflags) * likely to reclaim it. */ vm_page_aflag_set(fs->m, PGA_REFERENCED); - if (fs->object != fs->first_object) { + if (vm_fault_might_be_cow(fs)) { vm_fault_page_release(&fs->first_m); vm_object_pip_wakeup(fs->first_object); } @@ -1710,7 +1716,7 @@ found: * top-level object, we have to copy it into a new page owned by the * top-level object. */ - if (fs.object != fs.first_object) { + if (vm_fault_might_be_cow(&fs)) { /* * We only really need to copy if we want to write it. */