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 CBCEFC71148 for ; Fri, 13 Jun 2025 18:53:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5369A6B007B; Fri, 13 Jun 2025 14:53:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4E7716B0089; Fri, 13 Jun 2025 14:53:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3AF206B008A; Fri, 13 Jun 2025 14:53:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 1AD816B007B for ; Fri, 13 Jun 2025 14:53:30 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 514C21019FB for ; Fri, 13 Jun 2025 18:53:29 +0000 (UTC) X-FDA: 83551275738.18.715D3C1 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf24.hostedemail.com (Postfix) with ESMTP id E4838180004 for ; Fri, 13 Jun 2025 18:53:26 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NXhis2Bo; spf=pass (imf24.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1749840807; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Gftgj3F7KbsxQl1OCCcu039clX1oCiOXcGuSy3kjDUU=; b=NTmsFtFXfD3YEGaIfp18Xn6n9WWnEL+jW4LIYWhQbbogw+6n5aUBrt1CpO9+5GZlcP/G3w wu8NOyG+/9tBZWwbhtSLDqUN0Mjk/m7jWBAxGSt5xGEqZDKjWBd10aW1qMadsehvokl8Fa jCISX3dbQ8u5U/JYE6fDtOrJVmKQD0w= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NXhis2Bo; spf=pass (imf24.hostedemail.com: domain of peterx@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1749840807; a=rsa-sha256; cv=none; b=R34k/yqsbZWSMVvecbmR3TNXfy6JacPdG1aFaGNevGARAR/FR/bEgCiKuIz4ngeeZ0UJ1T tU3RnMTlhRVP2OhinDsUIvt+65rjBOhlrBK2GrFmFlLXS4mMdI++WdqH0OFFUUUJhH03Ef BVRxzJy2rRrGBfVU+Rxx2kjS9WUlENk= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749840806; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Gftgj3F7KbsxQl1OCCcu039clX1oCiOXcGuSy3kjDUU=; b=NXhis2Bohhjx35yIU7p1KrkiM6itgQeQF5GKDpWp+5jaOhSKhaDUNUn9J3AjBq2uqAxxpT pNfGWAxMVFozcWEjvfg73nSgeyDSBF5sk4ZsYAF4A7XMIgfuyucEMDp+RyNySdheqzswbg 8PzurdxNveLTXoFPvxHTi9XBEKkZgcQ= Received: from mail-qk1-f199.google.com (mail-qk1-f199.google.com [209.85.222.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-447-B6Z40sOvOS6U0hRRX3Ec0Q-1; Fri, 13 Jun 2025 14:53:25 -0400 X-MC-Unique: B6Z40sOvOS6U0hRRX3Ec0Q-1 X-Mimecast-MFC-AGG-ID: B6Z40sOvOS6U0hRRX3Ec0Q_1749840804 Received: by mail-qk1-f199.google.com with SMTP id af79cd13be357-7c793d573b2so394364785a.1 for ; Fri, 13 Jun 2025 11:53:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749840803; x=1750445603; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Gftgj3F7KbsxQl1OCCcu039clX1oCiOXcGuSy3kjDUU=; b=u/kV7UpSjkCbH6WsCClYdSy1+1CaNxeWDfwL4yL2F5PDiErz0RPIcyMIm0XAWaymIZ THQqlJbyZdHf8h2tp0HBR8Xw8IlLUrICqOsazgcAu+NE/XbriUZuf5w1sAK258Q0ypng DDUSRTgjhSnf9eLOl2ZirS7b69OCe7aGMHVPlNV9VzImm1gcX68RFlX4Wpcg2MVwLXuB okp+NZTS6PsDw4QgO3Vbbl5uF11ahZ8UPwOjTUzdeHJlwFuoibAwlle9lfvNTWxbmPCw V1oaNIxLEFErpLVUK1761Maq18kZK3POBbE2LXW6ajucgiTObsq6jPN8VMCUPz59XUCW R29Q== X-Forwarded-Encrypted: i=1; AJvYcCX7iNQllbfQp3HHYxSfUx4Q052DtvZzwDesAMdZN4MEo8Cz7i8TSYmqPuUvhXODs/9PltReJGyJ3Q==@kvack.org X-Gm-Message-State: AOJu0YwYJxx6iwYTnjKlP6qoF6FYjkd/LyMIx+WAqpDDOHRqBJBuFv1Z 9c53Iu2R7w6U/x0XMZaMfLseHaoqL0vlFZvxk34TLZAy58QchL8XZ3IIEBEdHNWZ6f9ima6SrK8 tythjQ61P/8ltc/YRVDAkkHMtQD8qUC8rwXfHoRRzvaA2fRqJY7dQ X-Gm-Gg: ASbGncsOXldm/3LaGXxV81BynmmSlztUOGZZFgv5vEDmc9/dg0C9AQaFZ+ZJ3Ebfxm2 T6WJbnPnpzguH6Csz75lfYygcW2v1GVc90jjYcamzPL33QGMaI5hDtnwi6Z1MbOfR1iwCayqfRO +v/ebnLjuyXrjL2Q6VjkKFgjed1r7GIhZK24lx35449yw2gQY14HrN7w7+IZyPcVaCmhextrs/H Q9cAJrvgqjMMgIIMUW8B62+1zASYFP+UODwwDgJOQyq4b5cc0FLIwcQvK0DTN6JAtwIJu28eUyI A8DMt8YfpAaVkA== X-Received: by 2002:a05:620a:29d0:b0:7d3:a6f2:74f2 with SMTP id af79cd13be357-7d3c6cff068mr94635485a.55.1749840802677; Fri, 13 Jun 2025 11:53:22 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGXcJDc+6SfZZjG6WukyvvwVpmRG1A1uzOdQlYb7eX3XEFjC1NczC7Ki5Dki/oYEcd/wf85cQ== X-Received: by 2002:a05:620a:29d0:b0:7d3:a6f2:74f2 with SMTP id af79cd13be357-7d3c6cff068mr94631685a.55.1749840802254; Fri, 13 Jun 2025 11:53:22 -0700 (PDT) Received: from x1.local ([85.131.185.92]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7d3b8dce692sm207001285a.14.2025.06.13.11.53.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 13 Jun 2025 11:53:21 -0700 (PDT) Date: Fri, 13 Jun 2025 14:53:19 -0400 From: Peter Xu To: Alex Mastro Cc: akpm@linux-foundation.org, alex.williamson@redhat.com, david@redhat.com, jgg@nvidia.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, npache@redhat.com, ziy@nvidia.com Subject: Re: [PATCH 5/5] vfio-pci: Best-effort huge pfnmaps with !MAP_FIXED mappings Message-ID: References: <20250613134111.469884-6-peterx@redhat.com> <20250613174442.1589882-1-amastro@fb.com> MIME-Version: 1.0 In-Reply-To: <20250613174442.1589882-1-amastro@fb.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: mzN4jyEg0dS8L9vFHIiX8sqFHWCZKzZPgTYyDHAAc6E_1749840804 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: E4838180004 X-Stat-Signature: ar9jjm8y6i4safna5fwf7i5pc9ymskdp X-Rspam-User: X-HE-Tag: 1749840806-45020 X-HE-Meta: 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 79bfOSMf ogqBNQDUr3ZAuWYdzIve/yd8hAdRDWNUccITQLr11Kjvlfj1vk1IbnPjU0KXk8hk6Ws2dUlo/9Yb6Bx9IuauBylRSbCuagtR1eJE4y3TjWPFu8mX6hHCY12250iBRpd5udMDvtFqNbWLtKAn2+Iidd6gA9IJZGuVUtZSma43dJtQHYvyo3py38UGPxM2z6X/FUaU5tDqEKcNxR1+ykSQTxzGYAbkJwIf/Qx7cVHMz+2mYKIQ3a2NdCwvqoWyzLlRDvHPFP5LTGIsDu/UG31HjLbfcLtYjL5tMRtKQ9X3euiSWv8KlQJCT43ukwUzyPEj2VqygBr/QZ1G9v4wx2C9eR5LuxBquzktC4BslDhpyXZA2pMdQRD8u9MOgEO86InKsyKpeIJHmDxFCbN+ltIObLgN/g1f63mGrq6NeoRRDVdBfIVUW+u3poARcsA6TpbZf4cCEgwsLjpH2dMhuD8iWL1q5/Dg8VCB7MvAO 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: List-Subscribe: List-Unsubscribe: On Fri, Jun 13, 2025 at 10:44:42AM -0700, Alex Mastro wrote: > Thank you Peter! > > I packported this series to our 6.13.2 tree and validated that it does indeed > provide equivalent, optimal faulting to our manual alignment approach when we > mmap with !MAP_FIXED. This addresses the issue we discovered in [1]. > > The test case is performing mmap with offset=0x40006000000, size=0xdf9e00000, > and we see that the head and tail (975) are faulted at 2M, and middle (54) at > 1G. The vma returned by mmap looks nice: 0x7f8646000000. > > $ sudo bpftrace -q -e 'fexit:vfio_pci_mmap_huge_fault { printf("order=%d, ret=0x%x\n", args.order, retval); }' 2>&1 > ~/dump > $ cat ~/dump | sort | uniq -c | sort -nr > 975 order=9, ret=0x100 > 54 order=18, ret=0x100 > 2 order=18, ret=0x800 > > [1] https://lore.kernel.org/linux-pci/20250529214414.1508155-1-amastro@fb.com/ > > Tested-by: Alex Mastro Great to know it works as expected, thanks for the quick feedback! -- Peter Xu