From nobody Thu Apr 9 02:37:34 2026 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 4frkcG5223z6YGX6 for ; Thu, 09 Apr 2026 02:37:34 +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" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4frkcG2V52z3VYY for ; Thu, 09 Apr 2026 02:37:34 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1775702254; 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=CQUq+dFvmCBJTnm/acR8vPydDWozbTuOrPC8m/UrGsU=; b=oozg7Hv4Hof+u4Z6qxUD22/ROvSvVmhjRuSLuecgsv84DlIbEOJye6uL8B7sGukHiqceI6 KgnCSNW24a807j+OrSvPcTX+HUbxfLuvhfQHAuHktVyUHCEProro7bSl+2cF+uFD3CNVQl BaMu415uAIxeshRRX/raUOQZ33gu8wHHleb4zb9zg902HBgiqgeLWPl6XREuJQWwIYIxdR tII3pM0D5oTFKBR6pd3j1QrgZ1qZfGguJDlc0Ud56Wg9R2mEg8GkFRr9tn8KyuodEBCEBH zc5ZcfC+auLc2M1dp5zts87LlsmoTLDVBP5UR3SGMbVBDbbnsE1hNBJv9faXhQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1775702254; a=rsa-sha256; cv=none; b=vA3MzmySYcFS/QZ90XPpRnntfUfa0aosHTF/aRrQ/Pt6XZlSn30mnjo5Xbjm0O+Jed3Feb UDoQC8qMHFGQm+RQHr9Dxvxy0WIXuwZvt0h6aAvDRETxoALM5DS7tv4rJMNgSk2Y8hN6hY 9LJh5QCxBY8tQQOno//1JEqTzbQPbem9ArQuBT+ovlSPwx0qgn2TzWqh3ELPdsxg1C37cn ofgvUzAmQqavPAugip7UUONWf/vsj8HCZ7eMwc/+nvOuIJRyMYwTbirPKm8Bj37SswhdUA 1iMH9/9iEo1FG6Av+6GvpMhJHgftbca2LWfVrJpUa5vXL//wRgOYAWZDuSxJDg== 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=1775702254; 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=CQUq+dFvmCBJTnm/acR8vPydDWozbTuOrPC8m/UrGsU=; b=A5bpnaaPP+1+t0r4nL7Lo4tOb+GXE0RYjGK2gmbpmVXJO15+FZAa8APY9HZUczjFN1ik2L UQwYkD0HWjn1JObfUfH3Hs76MelBNGd56CbSPg9abrKi3IARP23C/8dB+uyJQhfIrI8yFN bEzHe01Ssy9jac1tENpBXglAdGI02hRpoa/Rin/4fC/pY65LCGTSWGJb8S9vJhLvmOkVME skElwtKroufLmWRhuXnoXinHWTutzKNJqnjy2KLImYTlp3T656wXDU5CBpUkLbp2ZMG3/1 Y2oRKF4E9KSCVW5lPEoRC94F74csIKrLx4E4YEMBx/I+x9VH2hkB2W/gYLUPZg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4frkcG1qQNzv68 for ; Thu, 09 Apr 2026 02:37:34 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 4301d by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 09 Apr 2026 02:37:34 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Kyle Evans Subject: git: c6dd40f2d35d - main - kqueue: slightly clarify the flow in knlist_cleardel() 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: kevans X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: c6dd40f2d35d596ca60a5d87616c3e4a0fd4f676 Auto-Submitted: auto-generated Date: Thu, 09 Apr 2026 02:37:34 +0000 Message-Id: <69d710ee.4301d.2fffd704@gitrepo.freebsd.org> The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=c6dd40f2d35d596ca60a5d87616c3e4a0fd4f676 commit c6dd40f2d35d596ca60a5d87616c3e4a0fd4f676 Author: Kyle Evans AuthorDate: 2026-04-09 02:37:00 +0000 Commit: Kyle Evans CommitDate: 2026-04-09 02:37:11 +0000 kqueue: slightly clarify the flow in knlist_cleardel() This is purely a cosmetic change to make it a little easier on the eyes, rather than jumping back to the else branch up top. Re-flow it to use another loop on the outside and just inline the re-lock before we repeat after awaking from fluxwait. The !killkn path should maybe issue a wakeup if there's a thread in KQ_SLEEP so that userland can observe the EOF, but this isn't a practical problem today: pretty much every case of knlist_clear is tied to a file descriptor and called in the close(2) path. As a consequence, potentially affected knotes are almost always destroyed before we even get to knlist_clear(). Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D56226 --- sys/kern/kern_event.c | 50 +++++++++++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 21 deletions(-) diff --git a/sys/kern/kern_event.c b/sys/kern/kern_event.c index 1deb7a705c56..01731ca46b6b 100644 --- a/sys/kern/kern_event.c +++ b/sys/kern/kern_event.c @@ -2792,31 +2792,39 @@ knlist_cleardel(struct knlist *knl, struct thread *td, int islocked, int killkn) KNL_ASSERT_LOCKED(knl); else { KNL_ASSERT_UNLOCKED(knl); -again: /* need to reacquire lock since we have dropped it */ knl->kl_lock(knl->kl_lockarg); } - SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { - kq = kn->kn_kq; - KQ_LOCK(kq); - if (kn_in_flux(kn)) { - KQ_UNLOCK(kq); - continue; - } - knlist_remove_kq(knl, kn, 1, 1); - if (killkn) { - kn_enter_flux(kn); - KQ_UNLOCK(kq); - knote_drop_detached(kn, td); - } else { - /* Make sure cleared knotes disappear soon */ - kn->kn_flags |= EV_EOF | EV_ONESHOT; - KQ_UNLOCK(kq); + for (;;) { + /* + * Each pass removes as many knotes as we can before dropping + * into FLUXWAIT. Active knotes are simply detached and either + * freed or converted to one-shot, as the attached subject is + * essentially disappearing. + */ + SLIST_FOREACH_SAFE(kn, &knl->kl_list, kn_selnext, kn2) { + kq = kn->kn_kq; + KQ_LOCK(kq); + if (kn_in_flux(kn)) { + KQ_UNLOCK(kq); + continue; + } + knlist_remove_kq(knl, kn, 1, 1); + if (killkn) { + kn_enter_flux(kn); + KQ_UNLOCK(kq); + knote_drop_detached(kn, td); + } else { + /* Make sure cleared knotes disappear soon */ + kn->kn_flags |= EV_EOF | EV_ONESHOT; + KQ_UNLOCK(kq); + } + kq = NULL; } - kq = NULL; - } - if (!SLIST_EMPTY(&knl->kl_list)) { + if (SLIST_EMPTY(&knl->kl_list)) + break; + /* there are still in flux knotes remaining */ kn = SLIST_FIRST(&knl->kl_list); kq = kn->kn_kq; @@ -2826,7 +2834,7 @@ again: /* need to reacquire lock since we have dropped it */ kq->kq_state |= KQ_FLUXWAIT; msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqkclr", 0); kq = NULL; - goto again; + knl->kl_lock(knl->kl_lockarg); } if (islocked)