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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 679A0FC5933 for ; Thu, 26 Feb 2026 11:35:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C7DEE6B00B9; Thu, 26 Feb 2026 06:35:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C5F686B00BB; Thu, 26 Feb 2026 06:35:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B92AB6B00BC; Thu, 26 Feb 2026 06:35:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A34D96B00B9 for ; Thu, 26 Feb 2026 06:35:09 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 68A7D13C0C1 for ; Thu, 26 Feb 2026 11:35:09 +0000 (UTC) X-FDA: 84486401538.09.84D85AB Received: from out-181.mta0.migadu.com (out-181.mta0.migadu.com [91.218.175.181]) by imf14.hostedemail.com (Postfix) with ESMTP id B7882100002 for ; Thu, 26 Feb 2026 11:35:07 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=vDnDtqlu; spf=pass (imf14.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772105707; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=90K3/Ap/gcMw9j71y2Oyck7qwp5+WMwh/4brt0FtyC0=; b=EyrwXvKlJOR+8C256XJEtInL0QLj9XNfl6bFUkI8M/vR0/O8AOdbVr1mOsObHIkXUtA7xT LRTrb6+GZga7O+spuwn+kDK+aoaNcnCJK7UqdYKasF8aNMDTSbAz8MBSyVp/UZg+lJJ/YN k/j0OTrX9xK6EHkEkJR/YEnZVlhcqpE= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=vDnDtqlu; spf=pass (imf14.hostedemail.com: domain of usama.arif@linux.dev designates 91.218.175.181 as permitted sender) smtp.mailfrom=usama.arif@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772105707; a=rsa-sha256; cv=none; b=bqAETZWIVd6C1rZ8qnz4KG8x04Ala0znAseWY80Gzde5vMa5wPTYafziBkmM/ZQuOzFDjb vwh2xjniTY6XWeEWIdj0ye2utCqIkMiSgCMDukt3eD0kMTaA627W9gyKl9MvWHdNLBaiH4 3yCpgoFoNTF77jEanHUbnrXxCUSnJDE= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772105706; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=90K3/Ap/gcMw9j71y2Oyck7qwp5+WMwh/4brt0FtyC0=; b=vDnDtqlus/KJ8Kb996zZEjIj0Q0OZrP9GY6JYe5v0jo/jHj6Hhvq7Y6+kbJrhcBUFwKCR+ ptXaefkfhEcHKSCBne13vyEB9khUI5H2IRECqYMjzQXrM98xkEITpmyhzIlR8rRiLVUScp 6fbItK2kptHjFBl0pkeiWG9RptvrStU= From: Usama Arif To: Andrew Morton , david@kernel.org, lorenzo.stoakes@oracle.com, willy@infradead.org, linux-mm@kvack.org Cc: fvdl@google.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, kas@kernel.org, baohua@kernel.org, dev.jain@arm.com, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com, maddy@linux.ibm.com, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, linux-s390@vger.kernel.org, Usama Arif Subject: [RFC v2 20/21] selftests/mm: add partial_mremap test for move_page_tables Date: Thu, 26 Feb 2026 03:23:49 -0800 Message-ID: <20260226113233.3987674-21-usama.arif@linux.dev> In-Reply-To: <20260226113233.3987674-1-usama.arif@linux.dev> References: <20260226113233.3987674-1-usama.arif@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: B7882100002 X-Stat-Signature: 3rwtqbzasn96ykfst98955qz3rncg88s X-Rspam-User: X-HE-Tag: 1772105707-452327 X-HE-Meta: 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 33oKBnwK sw7xCuprpZdymbvq505CTSqXafaQ1+RBne1Z5qgpCWywOHjDRiJE2wVeXPfFnp+qOQPX50rZg3molfFE6zgV5iANBO7tjTkXuIqRtdLa4/oBmq6OJAr0kD5v2DgQD+aGjkvrGPMYxlzuA+47KAjCRGJBEEFGDxiWLzpQ3n1GdnYW4hxEsdmJlgomJW+lKdzGVUBfWjRtUaiRbYag+mzLRDaYuRp3wt/m5wuNzQcHPl1NT8SZeHRH9iMiXXg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Add test for partial mremap on THP which exercises move_page_tables(). This verifies that partial mremap correctly splits the PMD, moves only the requested page, and preserves data integrity in both the moved region and the original mapping. Signed-off-by: Usama Arif --- .../testing/selftests/mm/thp_pmd_split_test.c | 50 +++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/tools/testing/selftests/mm/thp_pmd_split_test.c b/tools/testing/selftests/mm/thp_pmd_split_test.c index 3c9f05457efec..1f29296759a5b 100644 --- a/tools/testing/selftests/mm/thp_pmd_split_test.c +++ b/tools/testing/selftests/mm/thp_pmd_split_test.c @@ -203,4 +203,54 @@ TEST_F(thp_pmd_split, partial_mlock) self->split_pmd_failed_before); } +/* + * Partial mremap (move_page_tables) + * + * Tests that partial mremap of a THP correctly splits the PMD and + * moves only the requested portion. This exercises move_page_tables() + * which now handles split failures. + */ +TEST_F(thp_pmd_split, partial_mremap) +{ + void *new_addr; + unsigned long *ptr = (unsigned long *)self->aligned; + unsigned long *new_ptr; + unsigned long pattern = 0xABCDUL; + int ret; + + ret = allocate_thp(self->aligned, self->pmdsize); + if (ret) + SKIP(return, "Failed to allocate THP"); + + /* Write pattern to the page we'll move */ + ptr[self->pagesize / sizeof(unsigned long)] = pattern; + + /* Also write to first and last page to verify they stay intact */ + ptr[0] = 0x1234UL; + ptr[(self->pmdsize - self->pagesize) / sizeof(unsigned long)] = 0x4567UL; + + /* Partial mremap - move one base page from the THP */ + new_addr = mremap((char *)self->aligned + self->pagesize, self->pagesize, + self->pagesize, MREMAP_MAYMOVE); + if (new_addr == MAP_FAILED) { + if (errno == ENOMEM) + SKIP(return, "mremap failed with ENOMEM"); + ASSERT_NE(new_addr, MAP_FAILED); + } + + /* Verify data was moved correctly */ + new_ptr = (unsigned long *)new_addr; + ASSERT_EQ(new_ptr[0], pattern); + + /* Verify surrounding data is intact */ + ASSERT_EQ(ptr[0], 0x1234UL); + ASSERT_EQ(ptr[(self->pmdsize - self->pagesize) / sizeof(unsigned long)], 0x4567UL); + + /* Cleanup the moved page */ + munmap(new_addr, self->pagesize); + + log_and_check_pmd_split(_metadata, self->split_pmd_before, + self->split_pmd_failed_before); +} + TEST_HARNESS_MAIN -- 2.47.3