From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F26662CCC5 for ; Sat, 4 Jul 2026 00:54:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783126472; cv=none; b=KI87m4JPsb7cfCoan5QfeIoLzJnj81AtiQjxuevMxymmBzHeqm3kNBtuyZwQDJIazd7UdJ6076eM49E8eHV2wg9iT8lH0xh2yI0bbdxG+C2R9aJiYY8Zheo/IYKKpQW+6oHcqUYCyeoo9gKW061zZcIhnfs/nDHcFk/SiZWamj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783126472; c=relaxed/simple; bh=aGouokrM8mJnKJvhDV6HgF76R3G0Y9rbbW38WPCx60g=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References; b=r3DyQ3kc3ySytNch89sIB656GuFV47fi9pBnWKrjChh+XJAB4fDcJDujmggiks0wTnqwvxtysxvKyQAxZFLVMGgoXmHPizSR4uTzKUzZPGbm0aTctpcgho+1hKlAx8T3gFE4gMvreF+BLrDMN3BnDtr6xEXRHRWlH2WsHKy2DWI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UMEZsEtb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UMEZsEtb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DDE61F00A3A; Sat, 4 Jul 2026 00:54:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783126471; bh=aGouokrM8mJnKJvhDV6HgF76R3G0Y9rbbW38WPCx60g=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=UMEZsEtbS2+gIggwr6lMxFmTFAjl1eNSFQ9lwH3nG1FVvACTaOtHaJ/IU72GyCXTe axuWCA58A7sb7Nm55I8wJHsNXQwGd0CIRhXi1mny+pZw3VzxGJKEcLxjg/5eZ13yYw pFibVlHdldZzu/3ZtEJ7vi9BILSHw3y16sjz9QEFfZCvF9Uf7v2JEY3Y4jvWMjlJI4 chW5ZFjdyGwYaTt+rks5THz+d5veiQcvsTD4J2eGtr7dsRjs+TnK/MrrvLV5Q2y5g9 EzgTtIEiV9sV6c8vFBh9tKXjdNfSQxFjNLUTJ4kHoymUI5jLegyGFf8boHwxoi+znI U4x1UqTJ89OCQ== Date: Fri, 03 Jul 2026 14:54:31 -1000 Message-ID: From: Tejun Heo To: sashiko-bot@kernel.org Cc: sched-ext@lists.linux.dev Subject: Re: [PATCH sched_ext/for-7.3 21/32] sched_ext: Add reject DSQ for cap-rejected dispatches In-Reply-To: <20260703125746.0D8371F000E9@smtp.kernel.org> References: <20260703080159.2314350-1-tj@kernel.org> <20260703080159.2314350-22-tj@kernel.org> <20260703125746.0D8371F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: sched-ext@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: > [High] Infinite loop of deferred requeues for exiting tasks or tasks > on offline CPUs when the sub-scheduler lacks capabilities. This is intended - re-rejection is unbounded by design and a capless sub is ejected by the stall watchdog, as the function comment notes. > [High] Tasks undergoing migration (with p->migration_pending set) are > incorrectly rejected to reject_dsq and then skipped during > reenqueuing, leaving them stranded indefinitely. The WARN is an assertion. The migration stopper clears migration_pending before the re-enqueue, and queued tasks are skipped by scx_reenq_local(), so it shouldn't reach here. If it turns out it can, force-admitting it like migration-disabled is a straightforward follow-up. Thanks.