From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53364) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXWfE-0000h0-5G for qemu-devel@nongnu.org; Mon, 16 Mar 2015 11:10:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXWfA-00085R-06 for qemu-devel@nongnu.org; Mon, 16 Mar 2015 11:10:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53430) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXWf9-00085B-Of for qemu-devel@nongnu.org; Mon, 16 Mar 2015 11:10:39 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2GFAdFk002515 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 16 Mar 2015 11:10:39 -0400 Date: Mon, 16 Mar 2015 16:10:37 +0100 From: Kevin Wolf Message-ID: <20150316151037.GE4707@noname.redhat.com> References: <1426052578-25026-1-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1426052578-25026-1-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v3] block/null: Latency simulation by adding new option "latency-ns" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: qemu-devel@nongnu.org, Stefan Hajnoczi Am 11.03.2015 um 06:42 hat Fam Zheng geschrieben: > Aio context switch should just work because the requests will be > drained, so the scheduled timer(s) on the old context will be freed. > > Signed-off-by: Fam Zheng > > --- > v3: latency_ns -> latency-ns; Add documentation in qapi json. [Eric] > v2: Check for negative value; add sleep in null-co://. [Kevin] > --- > block/null.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++----- > qapi/block-core.json | 5 ++++- > 2 files changed, 54 insertions(+), 6 deletions(-) > > diff --git a/block/null.c b/block/null.c > index ec2bd27..602f93c 100644 > --- a/block/null.c > +++ b/block/null.c > @@ -12,8 +12,11 @@ > > #include "block/block_int.h" > > +#define NULL_OPT_LATENCY "latency-ns" > + > typedef struct { > int64_t length; > + int64_t latency_ns; > } BDRVNullState; > > static QemuOptsList runtime_opts = { > @@ -30,6 +33,12 @@ static QemuOptsList runtime_opts = { > .type = QEMU_OPT_SIZE, > .help = "size of the null block", > }, > + { > + .name = NULL_OPT_LATENCY, > + .type = QEMU_OPT_NUMBER, > + .help = "nanoseconds (approximated) to wait " > + "before completing request", > + }, > { /* end of list */ } > }, > }; > @@ -44,6 +53,11 @@ static int null_file_open(BlockDriverState *bs, QDict *options, int flags, > qemu_opts_absorb_qdict(opts, options, &error_abort); > s->length = > qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 1 << 30); > + s->latency_ns = > + qemu_opt_get_number(opts, NULL_OPT_LATENCY, 0); > + if (s->latency_ns < 0) { > + error_setg(errp, "latency-ns is invalid"); > + } > qemu_opts_del(opts); > return 0; If errp is set, we should also return a negative error code. Kevin