Am 27.02.2013 um 16:38 hat Dietmar Maurer geschrieben:
> > > Adding and IO queue and implement a scheduler is likely not what we want
> > > to
> > do.
> >
> > The starting point for something smarter than just no policy or
> > rate-limiting is
> > BlockDriverState->tracked_requests. block.c kee
> > Adding and IO queue and implement a scheduler is likely not what we want to
> do.
>
> The starting point for something smarter than just no policy or rate-limiting
> is
> BlockDriverState->tracked_requests. block.c keeps track of active requests
> using this list.
>
> The simplest policy us
On Tue, Feb 26, 2013 at 05:02:19PM +, Dietmar Maurer wrote:
> > If you want to implement an alternative to rate-limiting, please do it in a
> > separate patch series and make it work for all block job types.
>
> Well, I hoped you can see how to fix that. I guess the same applies for other
> t
> I just reread the code and noticed the delay is 1 microsecond, not 1
> millisecond.
Yes, It does not really add a delay.
> The problem is that this is a magic value. It worked on your machine with
> your
> workload, but there's no guarantee it works on anyone else's machine or
> workload. W
On Mon, Feb 25, 2013 at 03:49:11PM +, Dietmar Maurer wrote:
> > > We previously used LVM and run backup with 'idle' IO priority (CFQ) to
> > > avoid
> > such behavior.
> > >
> > > But qemu does not provide an IO queue where we can set scheduling
> > priorities?
> >
> > QEMU block jobs support
> QEMU is not in a position to implement global scheduling (priorities).
> The QEMU process only knows about one guest. If you have multiple guests on
> the host an I/O "priority" inside QEMU process A will not take into account
> QEMU process B.
I only want priorities inside the guest. The backu
On Mon, Feb 25, 2013 at 03:49:11PM +, Dietmar Maurer wrote:
> > > We previously used LVM and run backup with 'idle' IO priority (CFQ) to
> > > avoid
> > such behavior.
> > >
> > > But qemu does not provide an IO queue where we can set scheduling
> > priorities?
> >
> > QEMU block jobs support
> > We previously used LVM and run backup with 'idle' IO priority (CFQ) to avoid
> such behavior.
> >
> > But qemu does not provide an IO queue where we can set scheduling
> priorities?
>
> QEMU block jobs support rate-limiting. Set it to 10-20% of the disk's
> throughput
> and the slowness shou
On Mon, Feb 25, 2013 at 06:48:39AM +, Dietmar Maurer wrote:
> > > > > +for (; start < end; start++) {
> > > > > +if (block_job_is_cancelled(&job->common)) {
> > > > > +ret = -1;
> > > > > +break;
> > > > > +}
> > > > > +
> > > > > +/* we need
> > > > +for (; start < end; start++) {
> > > > +if (block_job_is_cancelled(&job->common)) {
> > > > +ret = -1;
> > > > +break;
> > > > +}
> > > > +
> > > > +/* we need to yield so that qemu_aio_flush() returns.
> > > > + * (without, VM do
On Thu, Feb 21, 2013 at 05:23:30AM +, Dietmar Maurer wrote:
> > > +static void coroutine_fn backup_run(void *opaque) {
> > > +BackupBlockJob *job = opaque;
> > > +BlockDriverState *bs = job->common.bs;
> > > +assert(bs);
> > > +
> > > +int64_t start, end;
> > > +
> > > +star
> > +bit = cluster_num % BITS_PER_LONG;
> > +val = job->bitmap[idx];
> > +if (dirty) {
> > +if (!(val & (1UL << bit))) {
> > +val |= 1UL << bit;
> > +}
> > +} else {
> > +if (val & (1UL << bit)) {
> > +val &= ~(1UL << bit);
> > +
On Wed, Feb 20, 2013 at 10:31:59AM +0100, Dietmar Maurer wrote:
> +typedef struct BackupBlockJob {
> +BlockJob common;
> +RateLimit limit;
> +uint64_t sectors_read;
> +unsigned long *bitmap;
> +int bitmap_size;
> +BackupDumpFunc *backup_dump_cb;
> +BlockDriverCompletionF
Function backup_job_create() creates a block job to backup a block device.
The coroutine is started with backup_job_start().
We call backup_do_cow() for each write during backup. That function
reads the original data and pass it to backup_dump_cb().
The tracked_request infrastructure is used to s
14 matches
Mail list logo
