From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta1.migadu.com (out-174.mta1.migadu.com [95.215.58.174]) (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 A2B611369BB for ; Sat, 5 Oct 2024 08:18:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728116322; cv=none; b=K6H0HYpVl2AQawA87osqYS4fB46ylDyhmm3C0BiodNzge3ndfaJtyk1c38V3N6EVEwILzfEBk49WosSST6M6Cn7hTPL8f2rqqgkN0ytspeVYrn0tmFfpRO/TOxH49xhpIEuhzrRyUPBkW4N3brd/9/DP3He2Dg1zdecuvuHEaHY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728116322; c=relaxed/simple; bh=ERneIrgLPRtWwRr7jfiUOeI59b33GahU8R7kfdUHHaU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AiUnp3LeG5nt/J4iVcoaL4t9KF+mHHJylre3LezezMW/cCngEvxJs24kkjgsBNenL2kKAU2eSdmqhw+9l7KeV1D3qQ1gllJjbjdXtUeoiFRIUTSsmUO96Brj8P73PXcVMabqoNK2Kcrw8Gu10gtNSahBZzoQOzP7WYdouWGkzbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=ZUetfGHl; arc=none smtp.client-ip=95.215.58.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="ZUetfGHl" Message-ID: <21e1b842-7662-46cb-9da7-fe37a3b3119b@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1728116318; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NMmkCzSXIAM+PLZxbf+a1AidtWBAPGqD1VWOkXNMcPo=; b=ZUetfGHlSxiTqLvxg1v3AM+K64bVN20czslKjjbF5TywuBJdYVWyEu54jBenAtlpBhHE+F AKa18sJR8W0TwofNKhn89ulvAHbmynuArQ+cJgPHcLIlug7bjNHXXq5xQWfGNqYWCa7fxq zonkQB3gbpcaKde/TTazAA8GwkMpP3Y= Date: Sat, 5 Oct 2024 16:18:06 +0800 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: blktests failures with v6.12-rc1 kernel To: Jens Axboe , Bart Van Assche , Shinichiro Kawasaki Cc: "linux-block@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "linux-scsi@vger.kernel.org" , "nbd@other.debian.org" , "linux-rdma@vger.kernel.org" References: <5cff6598-21f3-4e85-9a06-f3a28380585b@linux.dev> <9fe72efb-46b8-4a72-b29c-c60a8c64f88c@acm.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2024/10/5 9:41, Jens Axboe 写道: > On 10/4/24 7:26 PM, Zhu Yanjun wrote: >> ? 2024/10/5 0:31, Bart Van Assche ??: >>> On 10/4/24 5:40 AM, Zhu Yanjun wrote: >>>> So I add a jiffies (u64) value into the name. >>> I don't think that embedding the value of the jiffies counter in the kmem cache names is sufficient to make cache names unique. That sounds like a fragile approach to me. >> Sorry. I can not get you. Why jiffies counter is not sufficient to >> make cache names unique? And why is it a fragile approach? > 1 jiffy is an eternity, what happens if someone calls > kmem_cache_create() twice in that window? Got it. Thanks a lot. Zhu Yanjun > >> I read your latest commit. In your commit, the ida is used to make >> cache names unique. It is a good approach if it can fix this problem. > That seems over-engineered. Seems to me that either these things should > share a slab cache (why do they need one each, if they are the same > sized object?!). And if they really do need one, surely something ala: > > static atomic_long_t slab_index; > > sprintf(slab_name, "foo-%ld", atomic_inc_return(&slab_index)); > > would be all you need. > -- Best Regards, Yanjun.Zhu