From nobody Thu Aug 6 15:01:36 2026 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 4hG9Ts32pCz6nB7g for ; Thu, 06 Aug 2026 15:01:37 +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 "YR1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4hG9Tr751Hz3Djw for ; Thu, 06 Aug 2026 15:01:36 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1786028497; 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=Ca4m5wASvErPQfx0QI5xjK1cqdja0ZffpaZ02kLxb0s=; b=GOED1qMkN/pwPwT1fn1Z55k4/HBChhws7hNOLNJmKKsfpT673mWr6VEOJnNxZ0oSGVthiO dqK/Kr5OjLCJ4qIWem05xpEdOfEBlxxK0FzF8J5fn9lSSXpgO/U/g6MluSOmeWFLypc1YV DUhcEv4LPQX6Zc8K7xv+kSj76xRRUAeei5GczfWbZBp1hwly7sXUuxjRi4UuOREFxAtCVw pu9iEivFkOdKyk/ThI1TnaCvxM5Va7xCqNXAsa5pVhAyahFti75dwoQt7L8Z/bRBBgEStz /C3Wsi5tB1kjHZbqCmZ+lKduoXvh90/lIL/wlz4ScqNQA3CbKbw86hX5Bio4OA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1786028497; a=rsa-sha256; cv=none; b=NRrUdN8hM5fUYq6AcXUQ5w8fLVLvSZhYKn+L1/mIa5EKe51NrHbAps57o/LaLS8ZhkcXIF 7c9iwFWXewpcOrlBfk4VL5IvhHwDe1iYNcNEt31uKI17OMOi2C9JhurghonRyr1vhYvw68 i+f/DgYuRviepnlJzlP6rTPcWnow/MzCJU6eJtOGZZpZ5Bl1skj/b5e8J1B4J4JmSgaX5G I/ypxfGr1PaP9yZuRtS94dZTUrCDM0Q7D57OHeMKsZQacBnq4C3ZaOqAnMEQVjsvLhwcl2 RMIu3qw7YjpsIGFqMl+Mh7MLOYgkjo1AECwCoVYFxR8NoD9g4y4xZoTmuV6CUQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1786028497; 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=Ca4m5wASvErPQfx0QI5xjK1cqdja0ZffpaZ02kLxb0s=; b=VXXoA+mhuCQ2zlvUr9p2Kt1N4N6yR1ptpeaL0St3ezOvIg3SUdGbAS0t7oce8eetshhfpX CAC0jSSeyF+qDgqtrwZeeuQcAlW0xr2Bl1KL/895YZSuGn8k1JShIQ8XE1IPgfmxiSO7JR htXUbbbwcBRgh1UxINCYjl3QGQvryaqMlcE/T3pHoZip2cfzuZ2G/TO6IEQWwK45Zj3Uiq agMEhEoQewg48CK2BfNqaSwSul0MyOBn7nok0AsopqGlKi8Rz7CXERZaIqUMiXB1Lq5zrO rqO81kGH/Bl1UKiv14l/Mc44B+ztTAjgykx0Epz6A6rh6zXG67lb7LOybEN2+Q== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hG9Tr5fkwz8gl for ; Thu, 06 Aug 2026 15:01:36 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 45bca by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 06 Aug 2026 15:01:36 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Mark Johnston Subject: git: b35a7db4829a - stable/15 - kqueue: Allocate marker knotes on the stack 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 List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list 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: b35a7db4829ab9826bc428fc3ceaa766bbc0f519 Auto-Submitted: auto-generated Date: Thu, 06 Aug 2026 15:01:36 +0000 Message-Id: <6a74a1d0.45bca.e627d0b@gitrepo.freebsd.org> The branch stable/15 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=b35a7db4829ab9826bc428fc3ceaa766bbc0f519 commit b35a7db4829ab9826bc428fc3ceaa766bbc0f519 Author: Mark Johnston AuthorDate: 2026-07-24 20:06:40 +0000 Commit: Mark Johnston CommitDate: 2026-08-06 13:24:42 +0000 kqueue: Allocate marker knotes on the stack The scan marker was originally stack-allocated. In commit 1c0f9af5b5224, it became heap-allocated since the marker is visible to other threads and a scanning thread's stack may be swapped out. Now that kernel stacks can no longer be swapped out, we can avoid these heap allocations. Reviewed by: kib MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D58402 (cherry picked from commit bb933b1d1846b3a984670b8cd65450c3333188f6) --- sys/kern/kern_event.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index 2a1269ec6e3c..cbed1073fa58 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -2112,7 +2112,7 @@ kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, const struct timespec *tsp, struct kevent *keva, struct thread *td) { struct kevent *kevp; - struct knote *kn, *marker; + struct knote *kn, marker; struct knlist *knl; sbintime_t asbt, rsbt; int count, error, haskqglobal, influx, nkev, touch; @@ -2151,8 +2151,8 @@ kqueue_scan(struct kqueue *kq, int maxevents, struct kevent_copyops *k_ops, asbt = -1; } else asbt = 0; - marker = knote_alloc(M_WAITOK); - marker->kn_status = KN_MARKER; + memset(&marker, 0, sizeof(marker)); + marker.kn_status = KN_MARKER; KQ_LOCK(kq); retry: @@ -2175,13 +2175,13 @@ retry: goto done; } - TAILQ_INSERT_TAIL(&kq->kq_head, marker, kn_tqe); + TAILQ_INSERT_TAIL(&kq->kq_head, &marker, kn_tqe); influx = 0; while (count) { KQ_OWNED(kq); kn = TAILQ_FIRST(&kq->kq_head); - if ((kn->kn_status == KN_MARKER && kn != marker) || + if ((kn->kn_status == KN_MARKER && kn != &marker) || kn_in_flux(kn)) { if (influx) { influx = 0; @@ -2199,7 +2199,7 @@ retry: kq->kq_count--; continue; } - if (kn == marker) { + if (kn == &marker) { KQ_FLUX_WAKEUP(kq); if (count == maxevents) goto retry; @@ -2297,11 +2297,10 @@ retry: break; } } - TAILQ_REMOVE(&kq->kq_head, marker, kn_tqe); + TAILQ_REMOVE(&kq->kq_head, &marker, kn_tqe); done: KQ_OWNED(kq); KQ_UNLOCK_FLUX(kq); - knote_free(marker); done_nl: KQ_NOTOWNED(kq); if (nkev != 0) @@ -3178,7 +3177,7 @@ kqueue_fork_copy(struct filedesc *fdp, struct file *fp, struct file *fp1, struct proc *p1, struct thread *td) { struct kqueue *kq, *kq1; - struct knote *marker; + struct knote marker; int error, i; error = 0; @@ -3187,26 +3186,24 @@ kqueue_fork_copy(struct filedesc *fdp, struct file *fp, struct file *fp1, kq1 = fp1->f_data; kq = kq1->kq_forksrc; - marker = knote_alloc(M_WAITOK); - marker->kn_status = KN_MARKER; - marker->kn_kq = kq; + memset(&marker, 0, sizeof(marker)); + marker.kn_status = KN_MARKER; + marker.kn_kq = kq; KQ_LOCK(kq); for (i = 0; i < kq->kq_knlistsize; i++) { - kqueue_fork_copy_list(&kq->kq_knlist[i], marker, kq, kq1, + kqueue_fork_copy_list(&kq->kq_knlist[i], &marker, kq, kq1, p1, fdp); } if (kq->kq_knhashmask != 0) { for (i = 0; i <= kq->kq_knhashmask; i++) { - kqueue_fork_copy_list(&kq->kq_knhash[i], marker, kq, + kqueue_fork_copy_list(&kq->kq_knhash[i], &marker, kq, kq1, p1, fdp); } } kqueue_release(kq, 1); kq1->kq_forksrc = NULL; KQ_UNLOCK_FLUX(kq); - - knote_free(marker); return (error); }