Re: [Qemu-devel] [PATCH v5 1/4] block: add the command line support

[Zhi Yong Wu]

On Tue, Aug 9, 2011 at 8:25 PM, Stefan Hajnoczi <address@hidden> wrote:
> On Tue, Aug 9, 2011 at 5:17 AM, Zhi Yong Wu <address@hidden> wrote:
>> Signed-off-by: Zhi Yong Wu <address@hidden>
>> ---
>>  Makefile.objs   |    2 +-
>>  blockdev.c      |   39 +++++++++++++++++++++++++++++++++++++++
>>  qemu-config.c   |   24 ++++++++++++++++++++++++
>>  qemu-option.c   |   17 +++++++++++++++++
>>  qemu-option.h   |    1 +
>>  qemu-options.hx |    1 +
>>  6 files changed, 83 insertions(+), 1 deletions(-)
>>
>> diff --git a/Makefile.objs b/Makefile.objs
>> index 9f99ed4..06f2033 100644
>> --- a/Makefile.objs
>> +++ b/Makefile.objs
>> @@ -23,7 +23,7 @@ block-nested-y += raw.o cow.o qcow.o vdi.o vmdk.o cloop.o 
>> dmg.o bochs.o vpc.o vv
>>  block-nested-y += qcow2.o qcow2-refcount.o qcow2-cluster.o qcow2-snapshot.o 
>> qcow2-cache.o
>>  block-nested-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
>>  block-nested-y += qed-check.o
>> -block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o
>> +block-nested-y += parallels.o nbd.o blkdebug.o sheepdog.o blkverify.o 
>> blk-queue.o
>
> This does not build:
>  LINK  qemu-ga
> gcc: error: block/blk-queue.o: No such file or directory
>
> This Makefile.objs change should be in the commit that adds blk-queue.c.
>
> Each patch in a series should compile cleanly and can only depend on
> previous patches.  This is important so that git-bisect(1) can be
> used, it only works if every commit builds a working program.  It also
> makes patch review easier when the patch series builds up logically.
It seems that it will take a bit much time if we strictly stage the
hunks into each corresponding patch.:)
OK, i will.
>
>>  block-nested-$(CONFIG_WIN32) += raw-win32.o
>>  block-nested-$(CONFIG_POSIX) += raw-posix.o
>>  block-nested-$(CONFIG_CURL) += curl.o
>> diff --git a/blockdev.c b/blockdev.c
>> index c263663..9c78548 100644
>> --- a/blockdev.c
>> +++ b/blockdev.c
>> @@ -238,6 +238,10 @@ DriveInfo *drive_init(QemuOpts *opts, int 
>> default_to_scsi)
>>     int on_read_error, on_write_error;
>>     const char *devaddr;
>>     DriveInfo *dinfo;
>> +    BlockIOLimit io_limits;
>
> This structure is not undefined at this point in the patch series.
The hunk contained this structure will be staged in this patch.

>
>> +    bool iol_flag = false;
>> +    const char *iol_opts[7] = {"bps", "bps_rd", "bps_wr",
>> +                                "iops", "iops_rd", "iops_wr"};
>>     int is_extboot = 0;
>>     int snapshot = 0;
>>     int ret;
>> @@ -372,6 +376,36 @@ DriveInfo *drive_init(QemuOpts *opts, int 
>> default_to_scsi)
>>         return NULL;
>>     }
>>
>> +    /* disk io throttling */
>> +    iol_flag = qemu_opt_io_limits_enable_flag(opts, iol_opts);
>> +    if (iol_flag) {
>> +        memset(&io_limits, 0, sizeof(BlockIOLimit));
>> +
>> +        io_limits.bps[BLOCK_IO_LIMIT_TOTAL]  =
>> +                           qemu_opt_get_number(opts, "bps", 0);
>> +        io_limits.bps[BLOCK_IO_LIMIT_READ]   =
>> +                           qemu_opt_get_number(opts, "bps_rd", 0);
>> +        io_limits.bps[BLOCK_IO_LIMIT_WRITE]  =
>> +                           qemu_opt_get_number(opts, "bps_wr", 0);
>> +        io_limits.iops[BLOCK_IO_LIMIT_TOTAL] =
>> +                           qemu_opt_get_number(opts, "iops", 0);
>> +        io_limits.iops[BLOCK_IO_LIMIT_READ]  =
>> +                           qemu_opt_get_number(opts, "iops_rd", 0);
>> +        io_limits.iops[BLOCK_IO_LIMIT_WRITE] =
>> +                           qemu_opt_get_number(opts, "iops_wr", 0);
>> +
>> +        if (((io_limits.bps[BLOCK_IO_LIMIT_TOTAL] != 0)
>> +            && ((io_limits.bps[BLOCK_IO_LIMIT_READ] != 0)
>> +            || (io_limits.bps[BLOCK_IO_LIMIT_WRITE] != 0)))
>> +            || ((io_limits.iops[BLOCK_IO_LIMIT_TOTAL] != 0)
>> +            && ((io_limits.iops[BLOCK_IO_LIMIT_READ] != 0)
>> +            || (io_limits.iops[BLOCK_IO_LIMIT_WRITE] != 0)))) {
>> +            error_report("bps(iops) and bps_rd/bps_wr(iops_rd/iops_wr) \
>> +                                        cannot be used at the same time");
>> +            return NULL;
>> +        }
>> +    }
>> +
>>     on_write_error = BLOCK_ERR_STOP_ENOSPC;
>>     if ((buf = qemu_opt_get(opts, "werror")) != NULL) {
>>         if (type != IF_IDE && type != IF_SCSI && type != IF_VIRTIO && type 
>> != IF_NONE) {
>> @@ -483,6 +517,11 @@ DriveInfo *drive_init(QemuOpts *opts, int 
>> default_to_scsi)
>>
>>     bdrv_set_on_error(dinfo->bdrv, on_read_error, on_write_error);
>>
>> +    /* disk I/O throttling */
>> +    if (iol_flag) {
>> +        bdrv_set_io_limits(dinfo->bdrv, &io_limits);
>> +    }
>
> iol_flag and qemu_opt_io_limits_enable_flag() are not necessary.  If
> no limits were set then all fields will be 0 (unlimited).
Are they not necessary here? why? qemu_opt_io_limits_enable_flag is
used to determine if io_limits is enabled.
If yes, iol_flag will be set to ONE. So i think that they are necessay here.
>
> Stefan
>



-- 
Regards,

Zhi Yong Wu