From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45355) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1canAC-0003t7-DG for qemu-devel@nongnu.org; Mon, 06 Feb 2017 12:33:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1canAB-0006Pf-DR for qemu-devel@nongnu.org; Mon, 06 Feb 2017 12:33:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56464) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1canAB-0006PQ-7O for qemu-devel@nongnu.org; Mon, 06 Feb 2017 12:33:15 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 63F2B63144 for ; Mon, 6 Feb 2017 17:33:15 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" Date: Mon, 6 Feb 2017 17:32:55 +0000 Message-Id: <20170206173306.20603-6-dgilbert@redhat.com> In-Reply-To: <20170206173306.20603-1-dgilbert@redhat.com> References: <20170206173306.20603-1-dgilbert@redhat.com> Subject: [Qemu-devel] [PATCH v2 05/16] postcopy: enhance ram_block_discard_range for hugepages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, quintela@redhat.com Cc: aarcange@redhat.com From: "Dr. David Alan Gilbert" Unfortunately madvise DONTNEED doesn't work on hugepagetlb so use fallocate(FALLOC_FL_PUNCH_HOLE) qemu_fd_getpagesize only sets the page based off a file if the file is from hugetlbfs. Signed-off-by: Dr. David Alan Gilbert --- exec.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/exec.c b/exec.c index e040cdf..c25f6b3 100644 --- a/exec.c +++ b/exec.c @@ -3324,9 +3324,20 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length) errno = ENOTSUP; /* If we are missing MADVISE etc */ + if (rb->page_size == qemu_host_page_size) { #if defined(CONFIG_MADVISE) - ret = qemu_madvise(host_startaddr, length, QEMU_MADV_DONTNEED); + ret = qemu_madvise(host_startaddr, length, QEMU_MADV_DONTNEED); #endif + } else { + /* Huge page case - unfortunately it can't do DONTNEED, but + * it can do the equivalent by FALLOC_FL_PUNCH_HOLE in the + * huge page file. + */ +#ifdef CONFIG_FALLOCATE_PUNCH_HOLE + ret = fallocate(rb->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + start, length); +#endif + } if (ret) { ret = -errno; error_report("ram_block_discard_range: Failed to discard range " -- 2.9.3