From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com ([209.132.183.28]:43458 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751546AbdFPQLf (ORCPT ); Fri, 16 Jun 2017 12:11:35 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 93F7FC04B943 for ; Fri, 16 Jun 2017 16:11:34 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-12-139.pek2.redhat.com [10.72.12.139]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9B8E682E2E for ; Fri, 16 Jun 2017 16:11:33 +0000 (UTC) From: Zorro Lang Subject: [PATCH 3/4] fsstress: do memset randomly before write operations Date: Sat, 17 Jun 2017 00:11:05 +0800 Message-Id: <1497629466-22647-3-git-send-email-zlang@redhat.com> In-Reply-To: <1497629466-22647-1-git-send-email-zlang@redhat.com> References: <1497629466-22647-1-git-send-email-zlang@redhat.com> Sender: fstests-owner@vger.kernel.org To: fstests@vger.kernel.org List-ID: Recently we found a bug by trigger a page fault when io-vector of writev is in processing. If do memset between malloc() and write operations, memset will init the pages. So do memset randomly maybe help to cover above situation. Signed-off-by: Zorro Lang --- ltp/fsstress.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/ltp/fsstress.c b/ltp/fsstress.c index 4ff90d5..e1b73e4 100644 --- a/ltp/fsstress.c +++ b/ltp/fsstress.c @@ -1924,7 +1924,8 @@ do_aio_rw(int opno, long r, int flags) off = (off64_t)(lr % MIN(stb.st_size + (1024 * 1024), MAXFSIZE)); off -= (off % align); off %= maxfsize; - memset(buf, nameseq & 0xff, len); + /* randomly memset maybe trigger page fault at write time */ + if (random() / 2) memset(buf, nameseq & 0xff, len); io_prep_pwrite(&iocb, fd, buf, len, off); } else { off = (off64_t)(lr % stb.st_size); @@ -2455,7 +2456,8 @@ dwrite_f(int opno, long r) buf = memalign(diob.d_mem, len); off %= maxfsize; lseek64(fd, off, SEEK_SET); - memset(buf, nameseq & 0xff, len); + /* randomly memset maybe trigger page fault at write time */ + if (random() / 2) memset(buf, nameseq & 0xff, len); e = write(fd, buf, len) < 0 ? errno : 0; free(buf); if (v) @@ -3672,7 +3674,8 @@ write_f(int opno, long r) lseek64(fd, off, SEEK_SET); len = (random() % FILELEN_MAX) + 1; buf = malloc(len); - memset(buf, nameseq & 0xff, len); + /* randomly memset maybe trigger page fault at write time */ + if (random() / 2) memset(buf, nameseq & 0xff, len); e = write(fd, buf, len) < 0 ? errno : 0; free(buf); if (v) @@ -3733,7 +3736,8 @@ writev_f(int opno, long r) lseek64(fd, off, SEEK_SET); len = (random() % FILELEN_MAX) + 1; buf = malloc(len); - memset(buf, nameseq & 0xff, len); + /* randomly memset maybe trigger page fault at write time */ + if (random() / 2) memset(buf, nameseq & 0xff, len); iovcnt = (random() % MIN(len, IOV_MAX)) + 1; iov = malloc(sizeof(struct iovec) * iovcnt); -- 2.7.4