From nobody Wed Feb 11 05:17:38 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 4f9msH06dMz6Rtx1 for ; Wed, 11 Feb 2026 05:17:39 +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 "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4f9msG4sQTz3Sv4 for ; Wed, 11 Feb 2026 05:17:38 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1770787058; 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=Pw+/maxrgcmRFZu13sfrE18zY2RfsjvPAYohs1eKxKs=; b=BgWIxd3r8fgNxlHj32cYJhfadSliwBdvzFIvEzge4avXQ9XpuZVqHjVkly2F/LllW7AmHf 2cO0PsQfT4jdoCW8qawwR2l8yffgjOibmq1k7h/pRPBV5gbvVWZmADsTyCnqDUgefmJhg4 2W6gmfBYKbIDS0TrMVy2gz2TvVP3gYcX74lECjlFqyxnk+uveOfk/O6fnklj9KuU9C0741 9/X+Wr9fBGVEbYbaGhTJr1gfsgrVkFkRKCFhdlsD8L6TP4c98pZQjGQ0AdAYJ9Jf6RWaCb HnR1ZDDrZfzUsdiiGkB4Kd/UEK7U2m+p8wD4U+3W2l0ZC6EtD/Hk8ZKHESfwMQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1770787058; a=rsa-sha256; cv=none; b=FwdVy3/fCtohmUbZbEptmoFD2mOOeqYVgzf5X89oCqT3qGN7r9IQGpnJgSuAv+wIIrmme3 7DALqcgNPbPvFA9o/daZCskz4lFdWgieUO+c18f3LOWxh2Sd60mCFjQbs90CG866fcrGEa ovH78FOjtTMmWCiSY2zaOMaK4PYjib8NyfeeVzbVGdfJIVCaVRbACtpgAZ51wenK7ZbWT0 b/nUirfF7ledIXA2BxK7Sr6SzYbJ4BoNDhRbuHlC+BVqZeMVSkcEWwnMwi1KS/WzT2tlvx 3SApTBb6Zl3Gl0/OWel+2GIwnI0u7j6ISZEsZU86i0PMWPC8FCZwC92kdi5t+w== 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=1770787058; 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=Pw+/maxrgcmRFZu13sfrE18zY2RfsjvPAYohs1eKxKs=; b=iC56/ZR1/MbRRetpldwEwJyUnlbrdI7lwj06CoKoaXb/iS9HlmhJnqb6ZYTIrE8lca5g+T u88+vOtB1sdszw9OHh1f3Axf47rD/mZlFnpY+iEOedGNgDfrZSCBzK/iTy79HekQbEvNkq z0v2nRSjoTxhf8m+DU9usDj6tvh7SRiy9GFgoj07Fm1u51A6D3HkOpjYvlH+lG2eZTq4Ue S+/7ZMevjYb8wIeSaZ7kxDENsA/7cOlfr7BzFQbrTgCRZvkLtTQbot3TkgQa2qV2cfIwav AmkJhhsQ3x69vqlW50pZioBaXmN3+XhfNOtN4qt6bygliHITs9DpBDorJHf96g== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4f9msG4QQczcHb for ; Wed, 11 Feb 2026 05:17:38 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 2670f by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Wed, 11 Feb 2026 05:17:38 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Konstantin Belousov Subject: git: 68feaa1cf268 - stable/15 - SCHED_4BSD: maybe_resched() cannot schedule ast() for curthread 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: kib X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: 68feaa1cf2684c520829fb245bd4b9381e655c18 Auto-Submitted: auto-generated Date: Wed, 11 Feb 2026 05:17:38 +0000 Message-Id: <698c10f2.2670f.34166c50@gitrepo.freebsd.org> The branch stable/15 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=68feaa1cf2684c520829fb245bd4b9381e655c18 commit 68feaa1cf2684c520829fb245bd4b9381e655c18 Author: Konstantin Belousov AuthorDate: 2026-01-29 08:09:00 +0000 Commit: Konstantin Belousov CommitDate: 2026-02-11 05:12:38 +0000 SCHED_4BSD: maybe_resched() cannot schedule ast() for curthread (cherry picked from commit b249cb2b18b3fddae186d45fe6d984fc7bde10c4) --- sys/kern/kern_synch.c | 2 +- sys/kern/sched_4bsd.c | 21 +++++++++++++++++++-- sys/sys/proc.h | 1 + sys/sys/sched.h | 2 ++ 4 files changed, 23 insertions(+), 3 deletions(-) diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c index 0ab0ccb3d05b..22628c78d8a5 100644 --- a/sys/kern/kern_synch.c +++ b/sys/kern/kern_synch.c @@ -596,7 +596,7 @@ loadav(void *arg) loadav, NULL, C_DIRECT_EXEC | C_PREL(32)); } -static void +void ast_scheduler(struct thread *td, int tda __unused) { #ifdef KTRACE diff --git a/sys/kern/sched_4bsd.c b/sys/kern/sched_4bsd.c index 317b47da2cca..a47fe3ce72c3 100644 --- a/sys/kern/sched_4bsd.c +++ b/sys/kern/sched_4bsd.c @@ -108,6 +108,8 @@ struct td_sched { #define TDF_BOUND TDF_SCHED1 /* Bound to one CPU. */ #define TDF_SLICEEND TDF_SCHED2 /* Thread time slice is over. */ +#define TDP_RESCHED TDP_SCHED1 /* Reschedule due to maybe_resched(). */ + /* flags kept in ts_flags */ #define TSF_AFFINITY 0x0001 /* Has a non-"full" CPU set. */ @@ -274,6 +276,17 @@ sched_load_rem(void) KTR_COUNTER0(KTR_SCHED, "load", "global load", sched_tdcnt); SDT_PROBE2(sched, , , load__change, NOCPU, sched_tdcnt); } + +static void +maybe_resched_ast(struct thread *td, int tda) +{ + MPASS(td == curthread); /* We are AST */ + if ((td->td_pflags & TDP_RESCHED) != 0) { + td->td_pflags &= ~TDP_RESCHED; + ast_scheduler(td, tda); + } +} + /* * Arrange to reschedule if necessary, taking the priorities and * schedulers into account. @@ -281,10 +294,12 @@ sched_load_rem(void) static void maybe_resched(struct thread *td) { + struct thread *ctd; + ctd = curthread; THREAD_LOCK_ASSERT(td, MA_OWNED); - if (td->td_priority < curthread->td_priority) - ast_sched_locked(curthread, TDA_SCHED); + if (td->td_priority < ctd->td_priority) + ctd->td_pflags |= TDP_RESCHED; } /* @@ -621,6 +636,8 @@ sched_4bsd_setup(void) /* Account for thread0. */ sched_load_add(); + + ast_register(TDA_SCHED_PRIV, ASTR_UNCOND, 0, maybe_resched_ast); } /* diff --git a/sys/sys/proc.h b/sys/sys/proc.h index 0c9658fff725..7c4431ab0819 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -503,6 +503,7 @@ enum { TDA_SIGSUSPEND, TDA_MOD3, /* .. and after */ TDA_MOD4, + TDA_SCHED_PRIV, TDA_MAX, }; #define TDAI(tda) (1U << (tda)) diff --git a/sys/sys/sched.h b/sys/sys/sched.h index 08d8636aaa68..c7b7b849947c 100644 --- a/sys/sys/sched.h +++ b/sys/sys/sched.h @@ -188,6 +188,8 @@ sched_unpin(void) curthread->td_pinned--; } +void ast_scheduler(struct thread *td, int tda); + /* sched_add arguments (formerly setrunqueue) */ #define SRQ_BORING 0x0000 /* No special circumstances. */ #define SRQ_YIELDING 0x0001 /* We are yielding (from mi_switch). */