Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756081AbcLNOe6 (ORCPT ); Wed, 14 Dec 2016 09:34:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:50195 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755490AbcLNOe4 (ORCPT ); Wed, 14 Dec 2016 09:34:56 -0500 From: Andreas Schwab To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Minchan Kim , mbrugger@suse.de Subject: jemalloc testsuite stalls in memset X-Yow: A shapely CATHOLIC SCHOOLGIRL is FIDGETING inside my costume.. Date: Wed, 14 Dec 2016 15:34:54 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1377 Lines: 41 When running the jemalloc-4.4.0 testsuite on aarch64 with glibc 2.24 the test/unit/junk test hangs in memset: (gdb) r Starting program: /tmp/jemalloc/jemalloc-4.4.0/test/unit/junk [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". test_junk_small: pass test_junk_large: pass ^C Program received signal SIGINT, Interrupt. memset () at ../sysdeps/aarch64/memset.S:91 91 str q0, [dstin] (gdb) x/i $pc => 0xffffb7ddf54c : str q0, [x0] x0 is pointing to the start of this mmap'd block: 0xffffb7400000 0xffffb7600000 0x200000 0x0 Any attempt to contine execution or step over the insn still causes the process to hang here. Only after accessing the memory through the debugger the test successfully continues to completion. The kernel has been configured with transparent hugepages. CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS=y # CONFIG_TRANSPARENT_HUGEPAGE_MADVISE is not set CONFIG_TRANSPARENT_HUGE_PAGECACHE=y This issue has been bisected to commit b8d3c4c3009d42869dc03a1da0efc2aa687d0ab4 ("mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called"). Andreas. -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."