From nobody Fri Jan 30 05:06:34 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 4f2PB25f9Lz6Qc0B for ; Fri, 30 Jan 2026 05:06:34 +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 "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4f2PB23QhWz3pqt for ; Fri, 30 Jan 2026 05:06:34 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1769749594; 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=wOaLs/Le4V7qiyzW+DLm4P+bf5bm5k5bE0QBkbFq66U=; b=kvYPnEkToqGTsoACIoRRgs5n4zz2KvYIRml6oPfP3ieTIm7n007khNbPzGdRi2MHdVpMNi MASP3gxNDRm7XmuJrm1kWV8TMZCv7uQ+xNlFsg70MdqcADj6o1+fINo42MM5bWoEJua/X1 NG1SuH7bwBYpELCb4yGS3aDBU0PsKuTZH3kxMV4qhQBH6rCUtfgPaRJ/sBknDy30mjtKsf p8oRa6TWNX7gydkuKrqVVLyNN5rgMC2856HRLsxoe+GvukbA2I4uBPb41ByRnQ/9k4KhAu UK3Fg0ftJjPzbwDGEZmF2JorH5V2TWwv0VGqGimPzUTnn01Kw/fTfdi5JK/wYQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1769749594; a=rsa-sha256; cv=none; b=fzTnLKgBIO+Aoqb7sOOCAX/8B/QKtlGOX7fGa/qEOKSxozCi1CSapinblV/RHzH+zV9xci 8WhAHDblV0bSsDNV9GyBUDpt4jj99d6illkuodF+isMORYxCWzrl6kkt0q3UoASZKNIMnJ 83UagO4vhW84PNynaZlTch9zbajGSbCQSja9IznsXpgmaSm9upOOZweki68BCLDVLVBxEE ngUo3HfrW9ZDbk5iI5jLydMLZ/DO0Hbl4NTYh6owLCORuva8L/kpD3o/nDosUXSSpiSKy7 jOJPrEv2pdav9ja/AAfdNQj2exxln/i/NaSef3u3FSwPN3GG65BTGmod5O7HCg== 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=1769749594; 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=wOaLs/Le4V7qiyzW+DLm4P+bf5bm5k5bE0QBkbFq66U=; b=eIduaQ5H9kcwc20hEXhycXM8MSukagQwYWtUAiWNxQKOHmoClwOra/Qn95KJwFz1DK1exK wO00pLhgD317S7jY/cIs069eTI/jFN9jMJ8vDCmtTQ2MPrr90tTa5ZwvhKZ4FsWC2UMp7u y/BGj0AMi+8LoUvIeba7Nx9pCW7J4HUYQFtb+9QXtygt3mLyBPsIwN7mxM2EPf83slDHFz 3PYc5FUMuyEwBBGzd034XY3YSZMHUb5rG9Q04PJVm2eCjF7CXEw0AKX5BcF5KPAFnXhBSD Aw9EMaCCeztS3J9VyuNo838nc4PIAHo3EJwsOYSb9rT1GyWSs+p0dYq3r8Z3Vg== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4f2PB22Kynz18Nw for ; Fri, 30 Jan 2026 05:06:34 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 40062 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 30 Jan 2026 05:06:34 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Adrian Chadd Subject: git: 666599639cf6 - stable/14 - powerpc: put the isync inside the TD_LOCK() checking loop 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: adrian X-Git-Repository: src X-Git-Refname: refs/heads/stable/14 X-Git-Reftype: branch X-Git-Commit: 666599639cf6bd1c4ae1ff4adad8150a44d7a8d4 Auto-Submitted: auto-generated Date: Fri, 30 Jan 2026 05:06:34 +0000 Message-Id: <697c3c5a.40062.38faa329@gitrepo.freebsd.org> The branch stable/14 has been updated by adrian: URL: https://cgit.FreeBSD.org/src/commit/?id=666599639cf6bd1c4ae1ff4adad8150a44d7a8d4 commit 666599639cf6bd1c4ae1ff4adad8150a44d7a8d4 Author: Adrian Chadd AuthorDate: 2026-01-03 22:52:14 +0000 Commit: Adrian Chadd CommitDate: 2026-01-30 05:05:53 +0000 powerpc: put the isync inside the TD_LOCK() checking loop Fix a narrow window where the lock is unlocked but the checking CPU hasn't flushed things appropriately. Inside this window the CPU inside cpu_switch() will loop forever thinking the destination thread is still blocked/locked even though it is not. This manifests as the system hanging after starting all APs. I've seen this reliably trigger in qemu-system-ppc64 running power9 pseries guests; the more CPUs the more likely it triggers at boot. PR: kern/292167 Differential Revision: https://reviews.freebsd.org/D54478 Reviewed by: jhibbits MFC after: 1 week Relnotes: yes (cherry picked from commit 8df2e542146801fd01675e56724eaa567d04c209) --- sys/powerpc/powerpc/swtch32.S | 2 +- sys/powerpc/powerpc/swtch64.S | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/sys/powerpc/powerpc/swtch32.S b/sys/powerpc/powerpc/swtch32.S index 547e1c5a201b..ef1a397bf74d 100644 --- a/sys/powerpc/powerpc/swtch32.S +++ b/sys/powerpc/powerpc/swtch32.S @@ -141,8 +141,8 @@ cpu_switchin: blocked_loop: lwz %r7,TD_LOCK(%r2) cmpw %r6,%r7 - beq- blocked_loop isync + beq- blocked_loop #endif lwz %r17,TD_PCB(%r2) /* Get new current PCB */ diff --git a/sys/powerpc/powerpc/swtch64.S b/sys/powerpc/powerpc/swtch64.S index 5f80751c8a10..ba37274d32bb 100644 --- a/sys/powerpc/powerpc/swtch64.S +++ b/sys/powerpc/powerpc/swtch64.S @@ -194,8 +194,8 @@ cpu_switchin: blocked_loop: ld %r7,TD_LOCK(%r13) cmpd %r6,%r7 - beq- blocked_loop isync + beq- blocked_loop #endif ld %r17,TD_PCB(%r13) /* Get new PCB */