From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=61.135.153.141 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793317338; b=sCnzb07HQOobwDNQuNdsvmXwt9R77offkAxSFVdpfqSRwipjPPfbaD5C/xWKIr1hzzfd gBlVrkxZAaWRiEsb4j3ke12xBrUvRGZTvH2jb7ghe00JSA3UK768yuRmUGKt2wHnir9Hb 4E2OJaWvWjwDUwg7KYFWle3lS7UMZ+mf1n/pJxYSE2H5v/Cl1SqGl4f+qK4A4jXT9lk3y X1hVrX9xqoeYvT5+Zg9JnC+ag4kVg2hM+je2lviyb61WgwzqeWpp+qggfvOa+0uO3BjvX oY4wtFb7H6v0OppCcqk9SH2yHsDsAsCP6QQIGjNzP/oBIO6AB1OAMNv++XyxeSUd1qg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793317338; h=DMARC-Filter:DKIM-Signature:X-SMAIL-HELO:Received:X-Sender:X-Auth-ID: X-SMAIL-MID:X-SMAIL-UIID:From:To:Cc:Subject:Date:Message-ID: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=Nrvka/sQHSsmHaztz280hFS6KyrceCCtDg9eO6J04Sg=; b=aNcXUlGmddZFHxp+4Tg75DC6M4xILmEB0tJU8yKyH7Y3txMJbnHDlgfC8zt5STGj5mpl 2o08/GCmX2DLXNssKIGwaRnxLZuNjx0e9GbfH5W7rY+0uXJ+mULrbqtCPMLqAe8pbrAHR uGJvhmn6QTgIRC2NPPKs+y6T2IvQGg2bmTB5ALnBS+YNo+l7Ty/f8Kq9xTO4s76GNBQ24 8hUZyvOnmwsOodGZlN9Bdn3XgMpEH1gcdaIhZtuTai8HyJwfkAwgghBmhm/6bGDzTh0t0 oKMooUNeXmRdFXZUDaQyZFfxVGMnvzVsUODRyjzFgQMMnwGdJbP7UU/BGB0Ebwzd/gg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.remote-ip=61.135.153.141 Received: from smtp153-141.sina.com.cn (smtp153-141.sina.com.cn [61.135.153.141]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 24360606A31D for ; Thu, 29 Oct 2026 23:42:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 24360606A31D Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1793317328; bh=Nrvka/sQHSsmHaztz280hFS6KyrceCCtDg9eO6J04Sg=; h=From:Subject:Date:Message-ID; b=h6ozoZk4tBcP2xbFXM0MfAFwEYcy9iQkB272CCQSyLkyP9ciBU91l+SXyMGzLgAu2 /RBvRlamIL7lJhFgOyDedSIDEFez7okD1GyvtFBaD9PFk45/r963MWqI8yZS6rgEUZ 2pDatahBDzNed5BZ8N6DuyPQCtUq3nStSQ6c17Nc= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.254.2.154]) by sina.com (10.54.253.31) with ESMTP id 6AE3D9C4000031A9; Thu, 30 Oct 2026 07:42:00 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 346596816134 X-SMAIL-UIID: 9D7A95AF643B4E1D9E2D718F313014A2-20261030-074200-1 From: Hillf Danton To: Jarkko Sakkinen Cc: David Howells , Eric Biggers , James Morris , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, keyrings@vger.kernel.org Subject: Re: [PATCH v5] KEYS: key_garbage_collector(): process in chunks Date: Fri, 30 Oct 2026 07:41:48 +0800 Message-ID: <20261029234149.218-1-hdanton@sina.com> In-Reply-To: <20261029172918.2118600-1-jarkko@kernel.org> References: X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 29 Oct 2026 19:29:17 +0200 Jarkko Sakkinen wrote: > key_garbage_collector() has a design that is not resistant enough for > workqueue lockups. The duration scales up relative to the number of items > in the serial tree, which causes a reoccuring theme of being guilty of > causing workqueue lockups. > Given cond_resched() the gc work is not a cpu hog, and given concurrency workqueue can get individual cpu highly overloaded in short time, so what you delivered is a half backed croissant, HBC, as you failed to make it clear why lockup occurs when the number of gc items rockets up.