From nobody Fri Jul 24 21:07:26 2026 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 4h6LCz0tghz6mkZs for ; Fri, 24 Jul 2026 21:07:27 +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 4h6LCy60kfz3cRL for ; Fri, 24 Jul 2026 21:07:26 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1784927246; 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=eoKgsEzrXS+3JRZ6Vjyz84wMsGo4Dt6eyz8mXJhbPAk=; b=pp4xyUlVSqhbLN2OL2itPDwvxkU+cRNq0lMPB5x2zxKVp2+7ozQIXXoedL3tjsjMhl+vD0 PMhPOjaUc+4hzYUZyQnVysf6C/UucBYBDqj5FUlsDhSeCaRrvQ+TMkhln/GftB4RMwZ0/l OHZVtF8MzqVtt1o7WWVslsV+vSqYl3PhcLQVgFK11MVnHrHB+Al7HbTW7PdbhR46sYaOCe nDKzcMBfOCQD618liXEzxwv91oWMeTdoOHKaBW/22s+VNhDIJw6Pt9THElBkfrsLUJOMpO tjtRL2r2Fy87Yfy1C1gHI/TOvvw/cJkPbtgcPKqeML0JzOWKClfmO62I/MV0gg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1784927246; a=rsa-sha256; cv=none; b=h2ajFHbtIGQrg94vGF5DDeBVkIxE5/D38579JvkQO8ga+qH08f+d+cD0O8HUVXd7VzbnIK uEHPdEqNzqOkmk55wkMq2dcWjTdEfafCwtG77BgE7mPH99XV/2uOQUlEZLUKq6z0eqcGmJ QPiGzyNj2t7WQPTnvS2DGFstbkpztYSsuPDldwAg1CthkTVyF4VD++Y5T0AqjrVzIE3kZu ifjmPLh7S3I4bs8ubFIMUXkUS4a1sBoGDjmUyXGknnk0FywF2UlsLmM7aoBdV07wcL+SUu zCFXaekYUOtxhx1AzkuaGvKO37p793vdS/syCEH2FUCQCZbshxjgPQSEB8TUkA== 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=1784927246; 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=eoKgsEzrXS+3JRZ6Vjyz84wMsGo4Dt6eyz8mXJhbPAk=; b=PPHF512Kg39pcWM4nF9ytgMmIYBW5kDaVMX/kJyPF6ul5aks4IyC6gaYeHBfJuT+5jz8LU q7fq1ZyqrvHFzEKXR/eO0HZoW7sr7INPbt80y/IC9dennRflO8cL2VGPQ3tf720AWTHpwm uBiAxdAGKkN13PaP6Lc/1JZ/N8oXzl6AmbnC8smFTP454vPRZbXEBPysPiIgNFh0wl64lE wmQNW1n28HO1Bcwimq8lZpYJFTPsBsKIySD26I0TcqrdBNPyBFjDKcWOjWjb4rNgQTRJN4 ubvnKW1MdKZJzKz/5mR8aaxllWebKs9fBf9+bMUD1D07vtpPkLwwg/jStU48dg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4h6LCy55mrz176w for ; Fri, 24 Jul 2026 21:07:26 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 370b6 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 24 Jul 2026 21:07:26 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: bb933b1d1846 - main - kqueue: Allocate marker knotes on the stack 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: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@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/main X-Git-Reftype: branch X-Git-Commit: bb933b1d1846b3a984670b8cd65450c3333188f6 Auto-Submitted: auto-generated Date: Fri, 24 Jul 2026 21:07:26 +0000 Message-Id: <6a63d40e.370b6.1ef24e0c@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=bb933b1d1846b3a984670b8cd65450c3333188f6 commit bb933b1d1846b3a984670b8cd65450c3333188f6 Author: Mark Johnston AuthorDate: 2026-07-24 20:06:40 +0000 Commit: Mark Johnston CommitDate: 2026-07-24 20:06:40 +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 --- 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 e19415c8d443..f22d8ca7da11 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -2109,7 +2109,7 @@ 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; @@ -2148,8 +2148,8 @@ 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: @@ -2172,13 +2172,13 @@ 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; @@ -2196,7 +2196,7 @@ retry: kq->kq_count--; continue; } - if (kn == marker) { + if (kn == &marker) { KQ_FLUX_WAKEUP(kq); if (count == maxevents) goto retry; @@ -2294,11 +2294,10 @@ 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) @@ -3148,7 +3147,7 @@ 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; @@ -3157,26 +3156,24 @@ 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); }