From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="TtW7VWes" Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E044113 for ; Sun, 26 Nov 2023 22:44:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Lln/MLNoxESo+IJkYPxF+z/r1tUOxzWlL589Q/PQRxo=; b=TtW7VWesIzm+isqWMkapn1tfsS AVvAclAyyJx0k3KdrAAgVVGmhl4xAB0D8dhHTGQ/YJ+9h/C7greX7jOnmPHC6Wi2fDvMaugbUhms2 2u6l6ymjM0t0zmTFQndWP+LixXy43ZZvN6Aoq+ctcL31qPJOvvOHXQNazbJVqP70tBwuFzLzxJhl/ eibkz9jXp2DBQNMiv7Wd9mTZUUUiWZchMv3ImG+Ar73fOo66EHEgz6pxfncV9XsBjG16c7rnm1lA6 T6CBZaIJNA/gW0ar7+KzY3jf754GdEpiAy+4Jcg0pR0lVNjMic5PBfVkkpIkTmnMAOTwb2g66DWO/ CijLHeiQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1r7VML-001b9n-1Q; Mon, 27 Nov 2023 06:44:45 +0000 Date: Sun, 26 Nov 2023 22:44:45 -0800 From: Christoph Hellwig To: Yiming Xu Cc: song@kernel.org, linux-raid@vger.kernel.org, paul.e.luse@intel.com, firnyee@gmail.com Subject: Re: [RFC] md/raid5: optimize RAID5 performance. Message-ID: References: Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Hi Shushu, the work certainly looks interesting! However: > Optimized by using fine-grained locks, customized data structures, and > scattered address space. Achieves significant improvements in both > throughput and latency. this is a lot of work for a single Linux patch, we usually do that work pice by pice instead of complete rewrite, and for such signigicant changes the commit logs also tend to be a bit extensive. I'm also not quite sure what scattered address spaces are - I bet reading the paper (I plan to get to that) would explain it, but it also helps to explain the idea in the commit message. That's my high level nitpicking for now, I'll try to read the paper and the patch in detail and come back later.