From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f68.google.com ([209.85.221.68]:40220 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbgCZQrr (ORCPT ); Thu, 26 Mar 2020 12:47:47 -0400 Received: by mail-wr1-f68.google.com with SMTP id u10so8656278wro.7 for ; Thu, 26 Mar 2020 09:47:44 -0700 (PDT) Date: Thu, 26 Mar 2020 17:47:32 +0100 From: Petr Malat Subject: Re: [PATCH v3 3/8] lib: add zstd support to decompress Message-ID: <20200326164732.GA17157@ntb.petris.klfree.czf> References: <20200325195849.407900-1-nickrterrell@gmail.com> <20200325195849.407900-4-nickrterrell@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200325195849.407900-4-nickrterrell@gmail.com> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Nick Terrell Cc: Nick Terrell , linux-kernel@vger.kernel.org, Chris Mason , linux-kbuild@vger.kernel.org, x86@kernel.org, gregkh@linuxfoundation.org, Kees Cook , Kernel Team , Adam Borowski , Patrick Williams , rmikey@fb.com, mingo@kernel.org, Patrick Williams Hi! On Wed, Mar 25, 2020 at 12:58:44PM -0700, Nick Terrell wrote: > From: Nick Terrell > * Add unzstd() and the zstd decompress interface. Here I do not understand why you limit the window size to 8MB even when you read a larger value from the header. I do not see a reason why there should be such a limitation at the first place and if there should be, why it differs from ZSTD_WINDOWLOG_MAX. I removed that limitation to be able to test it in my environment and I found the performance is worst than with my patch by roughly 20% (on i7-3520M), which is a major drawback considering the main motivation to use zstd is the decompression speed. I will test on arm as well and share the result tomorrow. Petr