From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH v5 2/4] mm: Provide kernel parameter to allow disabling page init poisoning References: <20180925200551.3576.18755.stgit@localhost.localdomain> <20180925201921.3576.84239.stgit@localhost.localdomain> <20180926073831.GC6278@dhcp22.suse.cz> From: Dave Hansen Message-ID: Date: Wed, 26 Sep 2018 08:36:47 -0700 MIME-Version: 1.0 In-Reply-To: <20180926073831.GC6278@dhcp22.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org To: Michal Hocko , Alexander Duyck Cc: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, pavel.tatashin@microsoft.com, dave.jiang@intel.com, jglisse@redhat.com, rppt@linux.vnet.ibm.com, dan.j.williams@intel.com, logang@deltatee.com, mingo@kernel.org, kirill.shutemov@linux.intel.com List-ID: On 09/26/2018 12:38 AM, Michal Hocko wrote: > Why cannot you simply go with [no]vm_page_poison[=on/off]? I was trying to look to the future a bit, if we end up with five or six more other options we want to allow folks to enable/disable. I don't want to end up in a situation where we have a bunch of different knobs to turn all this stuff off at runtime. I'd really like to have one stop shopping so that folks who have a system that's behaving well and don't need any debugging can get some of their performance back. But, the *primary* thing we want here is a nice, quick way to turn as much debugging off as we can. A nice-to-have is a future-proof, slub-style option that will centralize things. Alex's patch fails at the primary goal, IMNHO because "vm_debug=-" is so weird. I'd much rather have "vm_debug=off" (the primary goal) and throw away the nice-to-have (future-proof fine-grained on/off). I think we can have both, but I guess the onus is on me to go and add a strcmp(..., "off"). :)