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 B65793AB5C7; Thu, 28 May 2026 09:16:12 +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=1779959773; cv=none; b=oPd1MMc7KwDT2VWOfIqUT8EyAWaChApxBBxyOWyqQtxRGbPRoFaXx+wtNmrBwZ0ocn9gYKMPZUGM3WePDjLLs6266xgNpSpWmt/NxfyYt/xgt9a0mD9z+Z1sbC7wdjfDh7YnNrbKmgQIz9zNnlOJcXl/+jrj9dIyGwoHGeUT+zI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779959773; c=relaxed/simple; bh=HxxQjJ5r0lgfP7vltLn+9TJYpcIBEsei94S95U5+g7Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=etR9tg69ByphJFvq4ZLOQ3TTXZawTIpyGGAW7PQMQRv4fzbgtJdb7AT04QtuBOG1/KSLK708O8f9fpxbjgpRl9HbMDI6FjhfqjGsNxD4ykQH7ejtZhFRI++mq67tBJV++aPyZFqe0EKyxlJRZUh0Cn/e6REyH/3TLBzMIaVHsXU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kjzqMZ0i; 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="kjzqMZ0i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB9BF1F000E9; Thu, 28 May 2026 09:16:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779959772; bh=ZS5mdGBUp9CWgagmhtWPpgUc1bksbZ1JeQXfzhQg4/c=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=kjzqMZ0iYUcAMeOp1Hxvzwn3xuYHg95O5ARGQoara35a1RzQsMjBSbwiJ2K/UjBdw W/YWIS1sk4MJzqYPX7OHOzqRWeK+3Oh9yS8tXK5JwtAUsAa+TfZX5LndWVGrLUbn4L FJTqBsU7Ce067NcD14cVHe+6wHnmbZz0H1dgjUwt9zCg1EXGBD02o9TDqbUvJ0CtCR TfC1/sfVcwFzhQzGttl6LMDERb2BPCX/jOweHkTIXtasFj19R3DoxXEyyIWm/69wVn MuRF8BWDOw23MUvbeiAedX20W/xSco9SwAyaUhsMHIee5+7D0OyIAONtf4F1l+yQa8 ZFFhr/O5cIz6g== Message-ID: Date: Thu, 28 May 2026 11:16:07 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: improve the kmem_cache_alloc_bulk API Content-Language: en-US To: Christoph Hellwig Cc: Harry Yoo , Andrew Morton , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Jesper Dangaard Brouer , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, io-uring@vger.kernel.org, kasan-dev@googlegroups.com, bpf@vger.kernel.org, netdev@vger.kernel.org References: <20260527070239.2252948-1-hch@lst.de> <20260527122148.GA6838@lst.de> <482ee03a-c5b3-4873-a550-cc5743068616@kernel.org> <20260528090508.GB8376@lst.de> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/28/26 11:05, Christoph Hellwig wrote: > On Wed, May 27, 2026 at 04:07:12PM +0200, Vlastimil Babka (SUSE) wrote: >> commit 46dea1744498 ("slab: refill sheaves from all nodes") from this January. >> Previously it was just interrupts enabled. >> >> > but by requiring separate functions so I somehow doubt that was meant. >> >> Yeah, it's expressed by the _nolock variants. But slab propagates it internally >> by the gfp flags, and since 46dea1744498 it affects kmem_cache_alloc_bulk(). > > So what are the GFP flags that affect spinning? I can't find anything > related to that in either Documentation/core-api/memory-allocation.rst or > include/linux/gfp_types.h. See gfpflags_allow_spinning(). The usage by slab and page allocator users was meant to be via _nolock() variants, not by removing the flags when calling the normal functions, hence it's not documented. But the abstraction has now leaked in the kmem_cache_alloc_bulk() case, hm. I think instead of documenting that, we should adjust the implementation in slab, if possible. I'll try to look into that.