From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1728CC433EF for ; Thu, 21 Apr 2022 03:19:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7E6116B0071; Wed, 20 Apr 2022 23:19:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7955B6B0073; Wed, 20 Apr 2022 23:19:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 637A16B0074; Wed, 20 Apr 2022 23:19:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 550D66B0071 for ; Wed, 20 Apr 2022 23:19:52 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 2C1C525C48 for ; Thu, 21 Apr 2022 03:19:52 +0000 (UTC) X-FDA: 79379431824.26.A09A432 Received: from mail-pg1-f180.google.com (mail-pg1-f180.google.com [209.85.215.180]) by imf27.hostedemail.com (Postfix) with ESMTP id D3CC340022 for ; Thu, 21 Apr 2022 03:19:50 +0000 (UTC) Received: by mail-pg1-f180.google.com with SMTP id x191so3526013pgd.4 for ; Wed, 20 Apr 2022 20:19:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:subject:to:cc:references:in-reply-to:mime-version :message-id:content-transfer-encoding; bh=O48qIPjrX8Xe0hflytk+FHKidZ/wdCazg6Nj2YRoxXo=; b=L3L+4mLfMDLwo5UlvqchVDDF4Qi7CtqsKTmdiaEZlGmsvIAZMw3p6AYJS7gAE8WrXg tKW3/VoOsgYHMtWFuL0zi++QHYRdzCY3Xc9w2TQ7opDKLR/1gCGnPNYfriESXqJZ/Si3 7Pxh6eQBywlasNG6EJcCN8H/UJUZeA0x9RAnzOHBFKKBwhp/vcAKiHmAJkipM39YyWKB vGOIDEprXI/ZniWjbZPUS+zFekYTH27x1hO66lZ3vSnmtTNFWAXb4rUVZKDunAvl8+ld gDrVlJQg12r7jgsVi3apxbYICirn6ZQIUNVo18XvK7iLO82CoqRQi1hOLkgMtlQCF3/0 t1pQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:subject:to:cc:references:in-reply-to :mime-version:message-id:content-transfer-encoding; bh=O48qIPjrX8Xe0hflytk+FHKidZ/wdCazg6Nj2YRoxXo=; b=QXumrdArT9j8YnhJCGiPXzPD2PpN3tLN4PiEl6KzZbVas44A8QgdskJTxIMpUdnCAS MHJkKRPtOiw6ALHIXSlMD3rEco1gcvxy8l9tIcvNHSEycBV49el4kdh5TP7VtrRY35VE lNS9Dv2t2AfCUo697y2WMzLrdNwXSHhujr1SHdKUjSkecubuRTQDslQxOII1ARvbf20x IeYHxtjE871cNIxMGmVZxtdGJfvJk9WlJONlS5QDBmEU28KrlKH492anxzAgjNDSD+BV iq3fxYZkELpEoSYTvg/ALk+9sHyG1qL9YbbwIM58UK4cwjJSjhZHAPoDaHXgB5wobCvR nhxA== X-Gm-Message-State: AOAM5329id82NJ99L9JGhbaPYKSB5rqjEHgOVrpkPz3BwIpmbzOrC+Kg sGh9fZAOOMiPJ6b/Vi7wD38= X-Google-Smtp-Source: ABdhPJxlj/Cv9i7bzjODu0drT5IErA6bWCTVIXD+VB8HfowEPzEjnAef10H1ZhO8T9QsXuZraBnlBA== X-Received: by 2002:a63:484f:0:b0:3aa:3f25:25a0 with SMTP id x15-20020a63484f000000b003aa3f2525a0mr9716006pgk.559.1650511190816; Wed, 20 Apr 2022 20:19:50 -0700 (PDT) Received: from localhost ([203.221.203.144]) by smtp.gmail.com with ESMTPSA id x184-20020a6286c1000000b0050ad3051f53sm1272382pfd.147.2022.04.20.20.19.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Apr 2022 20:19:50 -0700 (PDT) Date: Thu, 21 Apr 2022 13:19:43 +1000 From: Nicholas Piggin Subject: Re: [PATCH v4 bpf 0/4] vmalloc: bpf: introduce VM_ALLOW_HUGE_VMAP To: Christoph Hellwig , Luis Chamberlain Cc: akpm@linux-foundation.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, imbrenda@linux.ibm.com, kernel-team@fb.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, rick.p.edgecombe@intel.com, Song Liu References: <20220415164413.2727220-1-song@kernel.org> In-Reply-To: MIME-Version: 1.0 Message-Id: <1650511051.ez3mdems3d.astroid@bobo.none> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: D3CC340022 X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=L3L+4mLf; spf=pass (imf27.hostedemail.com: domain of npiggin@gmail.com designates 209.85.215.180 as permitted sender) smtp.mailfrom=npiggin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Stat-Signature: dwcjtjkyyubad65dcg8nezkgm7o58efq X-HE-Tag: 1650511190-523612 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Excerpts from Christoph Hellwig's message of April 16, 2022 3:08 pm: > On Fri, Apr 15, 2022 at 12:05:42PM -0700, Luis Chamberlain wrote: >> Looks good except for that I think this should just wait for v5.19. The >> fixes are so large I can't see why this needs to be rushed in other than >> the first assumptions of the optimizations had some flaws addressed here= . >=20 > Patches 1 and 2 are bug fixes for regressions caused by using huge page > backed vmalloc by default. So I think we do need it for 5.18. No, the huge vmap patch should just be reverted because that caused the regression, rather than adding another hack on top of it. All the breakage is in arch/x86/, it doesn't make sense to change this code and APIs outside x86 to work around it. And once they are fixed these shouldn't be needed. Thanks, Nick