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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-users] Re: [Xen-devel] VM disk I/O limit patch
On Tue, 21 Jun 2011 09:33:37 -0400
Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> wrote:
> On Tue, Jun 21, 2011 at 04:29:35PM +0800, Andrew Xu wrote:
> > Hi all,
> >
> > I add a blkback QoS patch.
>
> What tree is this against?
This patch is based on suse11.sp1(2.6.32) xen-blkback source.
(2.6.18 "Xenlinux" based source trees?)
> There is a xen-blkback in 3.0-rc4, can you rebase
> it against that please.
>
Ok, I will rebase it.
> What is the patch solving?
>
With this path, you can set different speed I/O for different VM disk.
For example, I set vm17-disk1 4MKB/s
vm17-disk2 1MKB/s
vm18-disk3 3MKB/s
I/O speed, by writing follow xenstore key-values.
/local/domain/17/device/vbd/768/tokens-rate = "4096"
/local/domain/17/device/vbd/2048/tokens-rate = "1024"
/local/domain/18/device/vbd/768/tokens-rate = "3096"
> Why can't it be done with dm-ioband?
Of cause, I/O speed limit also can be done with dm-ioband.
But with my patch, there is no need to load dm-ioband any more.
This patch do speed-limit more close disk, more lightweight.
How it doing?
1) It record how many sectors(512Bytes) have submit to disk in 1 second.
2) If it exceed 2*tokens-rate, then sleep (1 - time passed) seconds.
3) Next second come, going to 1)
> > You can config(dynamic/static) different I/O speed for different VM disk
> > by this patch.
> >
> > ----------------------------------------------------------------------------
> >
> > diff -urNp blkback/blkback.c blkback-qos/blkback.c
> > --- blkback/blkback.c 2011-06-22 07:54:19.000000000 +0800
> > +++ blkback-qos/blkback.c 2011-06-22 07:53:18.000000000 +0800
> > @@ -44,6 +44,11 @@
> > #include <asm/hypervisor.h>
> > #include "common.h"
> >
> > +#undef DPRINTK
> > +#define DPRINTK(fmt, args...) \
> > + printk("blkback/blkback (%s:%d) " fmt ".\n", \
> > + __FUNCTION__, __LINE__, ##args)
> > +
> > /*
> > * These are rather arbitrary. They are fairly large because adjacent
> > requests
> > * pulled from a communication ring are quite likely to end up being part
> > of
> > @@ -110,7 +115,8 @@ static inline unsigned long vaddr(pendin
> > static int do_block_io_op(blkif_t *blkif);
> > static int dispatch_rw_block_io(blkif_t *blkif,
> > blkif_request_t *req,
> > - pending_req_t *pending_req);
> > + pending_req_t *pending_req,
> > + int *done_nr_sects);
> > static void make_response(blkif_t *blkif, u64 id,
> > unsigned short op, int st);
> >
> > @@ -206,10 +212,20 @@ static void print_stats(blkif_t *blkif)
> > blkif->st_pk_req = 0;
> > }
> >
> > +static void refill_reqcount(blkif_t *blkif)
> > +{
> > + blkif->reqtime = jiffies + msecs_to_jiffies(1000);
> > + blkif->reqcount = blkif->reqrate;
> > + if (blkif->reqcount < blkif->reqmin)
> > + blkif->reqcount = blkif->reqmin;
> > +}
> > +
> > int blkif_schedule(void *arg)
> > {
> > blkif_t *blkif = arg;
> > struct vbd *vbd = &blkif->vbd;
> > + int ret = 0;
> > + struct timeval cur_time;
> >
> > blkif_get(blkif);
> >
> > @@ -232,12 +248,34 @@ int blkif_schedule(void *arg)
> > blkif->waiting_reqs = 0;
> > smp_mb(); /* clear flag *before* checking for work */
> >
> > - if (do_block_io_op(blkif))
> > + ret = do_block_io_op(blkif);
> > + if (ret)
> > blkif->waiting_reqs = 1;
> > unplug_queue(blkif);
> >
> > + if(blkif->reqmin){
> > + if(2 == ret && (blkif->reqtime > jiffies)){
> > + jiffies_to_timeval(jiffies, &cur_time);
> > + if(log_stats && (cur_time.tv_sec % 10 ==1 ))
> > + printk(KERN_DEBUG "%s: going to sleep
> > %d millsecs(rate=%d)\n",
> > + current->comm,
> > +
> > jiffies_to_msecs(blkif->reqtime - jiffies),
> > + blkif->reqrate);
> > +
> > + set_current_state(TASK_INTERRUPTIBLE);
> > + schedule_timeout(blkif->reqtime - jiffies);
> > +
> > + if(log_stats && (cur_time.tv_sec % 10 ==1 ))
> > + printk(KERN_DEBUG "%s: sleep
> > end(rate=%d)\n",
> > +
> > current->comm,blkif->reqrate);
> > + }
> > + if (time_after(jiffies, blkif->reqtime))
> > + refill_reqcount(blkif);
> > + }
> > +
> > if (log_stats && time_after(jiffies, blkif->st_print))
> > print_stats(blkif);
> > +
> > }
> >
> > if (log_stats)
> > @@ -306,7 +344,6 @@ irqreturn_t blkif_be_int(int irq, void *
> > /******************************************************************
> > * DOWNWARD CALLS -- These interface with the block-device layer proper.
> > */
> > -
> > static int do_block_io_op(blkif_t *blkif)
> > {
> > blkif_back_rings_t *blk_rings = &blkif->blk_rings;
> > @@ -314,15 +351,27 @@ static int do_block_io_op(blkif_t *blkif
> > pending_req_t *pending_req;
> > RING_IDX rc, rp;
> > int more_to_do = 0, ret;
> > + static int last_done_nr_sects = 0;
> >
> > rc = blk_rings->common.req_cons;
> > rp = blk_rings->common.sring->req_prod;
> > rmb(); /* Ensure we see queued requests up to 'rp'. */
> > +
> > + if (blkif->reqmin && blkif->reqcount <= 0)
> > + return (rc != rp) ? 2 : 0;
> >
> > while ((rc != rp) || (blkif->is_suspended_req)) {
> >
> > if (RING_REQUEST_CONS_OVERFLOW(&blk_rings->common, rc))
> > break;
> > +
> > + if(blkif->reqmin){
> > + blkif->reqcount -= last_done_nr_sects;
> > + if (blkif->reqcount <= 0) {
> > + more_to_do = 2;
> > + break;
> > + }
> > + }
> >
> > if (kthread_should_stop()) {
> > more_to_do = 1;
> > @@ -367,14 +416,14 @@ handle_request:
> > switch (req.operation) {
> > case BLKIF_OP_READ:
> > blkif->st_rd_req++;
> > - ret = dispatch_rw_block_io(blkif, &req, pending_req);
> > + ret = dispatch_rw_block_io(blkif, &req,
> > pending_req,&last_done_nr_sects);
> > break;
> > case BLKIF_OP_WRITE_BARRIER:
> > blkif->st_br_req++;
> > /* fall through */
> > case BLKIF_OP_WRITE:
> > blkif->st_wr_req++;
> > - ret = dispatch_rw_block_io(blkif, &req, pending_req);
> > + ret = dispatch_rw_block_io(blkif, &req,
> > pending_req,&last_done_nr_sects);
> > break;
> > case BLKIF_OP_PACKET:
> > DPRINTK("error: block operation BLKIF_OP_PACKET not
> > implemented\n");
> > @@ -412,9 +461,29 @@ handle_request:
> > return more_to_do;
> > }
> >
> > +static char* operation2str(int operation)
> > +{
> > + char* ret_str = NULL;
> > + switch (operation) {
> > + case BLKIF_OP_READ:
> > + ret_str = "READ";
> > + break;
> > + case BLKIF_OP_WRITE:
> > + ret_str = "WRITE";
> > + break;
> > + case BLKIF_OP_WRITE_BARRIER:
> > + ret_str = "WRITE_BARRIER";
> > + break;
> > + default:
> > + ret_str = "0";
> > + }
> > + return ret_str;
> > +}
> > +
> > static int dispatch_rw_block_io(blkif_t *blkif,
> > blkif_request_t *req,
> > - pending_req_t *pending_req)
> > + pending_req_t *pending_req,
> > + int *done_nr_sects)
> > {
> > extern void ll_rw_block(int rw, int nr, struct buffer_head * bhs[]);
> > struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST];
> > @@ -426,6 +495,9 @@ static int dispatch_rw_block_io(blkif_t
> > struct bio *bio = NULL;
> > int ret, i;
> > int operation;
> > + struct timeval cur_time;
> > +
> > + *done_nr_sects = 0;
> >
> > switch (req->operation) {
> > case BLKIF_OP_READ:
> > @@ -582,6 +654,12 @@ static int dispatch_rw_block_io(blkif_t
> > else if (operation == WRITE || operation == WRITE_BARRIER)
> > blkif->st_wr_sect += preq.nr_sects;
> >
> > + *done_nr_sects = preq.nr_sects;
> > + jiffies_to_timeval(jiffies, &cur_time);
> > + if ((log_stats == 2) && (cur_time.tv_sec % 10 ==1 ))
> > + printk(KERN_DEBUG " operation=%s sects=%d\n",
> > + operation2str(req->operation),preq.nr_sects);
> > +
> > return 0;
> >
> > fail_flush:
> > @@ -695,6 +773,8 @@ static int __init blkif_init(void)
> >
> > blkif_xenbus_init();
> >
> > + DPRINTK("blkif_inited\n");
> > +
> > return 0;
> >
> > out_of_memory:
> > diff -urNp blkback/cdrom.c blkback-qos/cdrom.c
> > --- blkback/cdrom.c 2010-05-20 18:07:00.000000000 +0800
> > +++ blkback-qos/cdrom.c 2011-06-22 07:34:50.000000000 +0800
> > @@ -35,9 +35,9 @@
> > #include "common.h"
> >
> > #undef DPRINTK
> > -#define DPRINTK(_f, _a...) \
> > - printk("(%s() file=%s, line=%d) " _f "\n", \
> > - __PRETTY_FUNCTION__, __FILE__ , __LINE__ , ##_a )
> > +#define DPRINTK(fmt, args...) \
> > + printk("blkback/cdrom (%s:%d) " fmt ".\n", \
> > + __FUNCTION__, __LINE__, ##args)
> >
> >
> > #define MEDIA_PRESENT "media-present"
> > diff -urNp blkback/common.h blkback-qos/common.h
> > --- blkback/common.h 2010-05-20 18:07:00.000000000 +0800
> > +++ blkback-qos/common.h 2011-06-22 07:34:50.000000000 +0800
> > @@ -100,8 +100,17 @@ typedef struct blkif_st {
> >
> > grant_handle_t shmem_handle;
> > grant_ref_t shmem_ref;
> > +
> > + /* qos information */
> > + unsigned long reqtime;
> > + int reqcount;
> > + int reqmin;
> > + int reqrate;
> > +
> > } blkif_t;
> >
> > +#define VBD_QOS_MIN_RATE_LIMIT 2*1024 /*
> > 1MBs */
> > +
> > struct backend_info
> > {
> > struct xenbus_device *dev;
> > @@ -111,6 +120,8 @@ struct backend_info
> > unsigned major;
> > unsigned minor;
> > char *mode;
> > + struct xenbus_watch rate_watch;
> > + int have_rate_watch;
> > };
> >
> > blkif_t *blkif_alloc(domid_t domid);
> > diff -urNp blkback/vbd.c blkback-qos/vbd.c
> > --- blkback/vbd.c 2010-05-20 18:07:00.000000000 +0800
> > +++ blkback-qos/vbd.c 2011-06-22 07:34:50.000000000 +0800
> > @@ -35,6 +35,11 @@
> > #define vbd_sz(_v) ((_v)->bdev->bd_part ?
> > \
> > (_v)->bdev->bd_part->nr_sects : get_capacity((_v)->bdev->bd_disk))
> >
> > +#undef DPRINTK
> > +#define DPRINTK(fmt, args...) \
> > + printk("blkback/vbd (%s:%d) " fmt ".\n", \
> > + __FUNCTION__, __LINE__, ##args)
> > +
> > unsigned long long vbd_size(struct vbd *vbd)
> > {
> > return vbd_sz(vbd);
> > @@ -87,7 +92,7 @@ int vbd_create(blkif_t *blkif, blkif_vde
> > if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE)
> > vbd->type |= VDISK_REMOVABLE;
> >
> > - DPRINTK("Successful creation of handle=%04x (dom=%u)\n",
> > + DPRINTK("Successful creation of handle=%04x (dom=%u)",
> > handle, blkif->domid);
> > return 0;
> > }
> > diff -urNp blkback/xenbus.c blkback-qos/xenbus.c
> > --- blkback/xenbus.c 2010-05-20 18:07:00.000000000 +0800
> > +++ blkback-qos/xenbus.c 2011-06-22 07:34:50.000000000 +0800
> > @@ -25,13 +25,14 @@
> >
> > #undef DPRINTK
> > #define DPRINTK(fmt, args...) \
> > - pr_debug("blkback/xenbus (%s:%d) " fmt ".\n", \
> > + printk("blkback/xenbus (%s:%d) " fmt ".\n", \
> > __FUNCTION__, __LINE__, ##args)
> >
> > static void connect(struct backend_info *);
> > static int connect_ring(struct backend_info *);
> > static void backend_changed(struct xenbus_watch *, const char **,
> > unsigned int);
> > +static void unregister_rate_watch(struct backend_info *be);
> >
> > static int blkback_name(blkif_t *blkif, char *buf)
> > {
> > @@ -59,8 +60,10 @@ static void update_blkif_status(blkif_t
> > char name[TASK_COMM_LEN];
> >
> > /* Not ready to connect? */
> > - if (!blkif->irq || !blkif->vbd.bdev)
> > + if (!blkif->irq || !blkif->vbd.bdev){
> > + DPRINTK("Not ready to connect");
> > return;
> > + }
> >
> > /* Already connected? */
> > if (blkif->be->dev->state == XenbusStateConnected)
> > @@ -193,6 +196,8 @@ static int blkback_remove(struct xenbus_
> > be->cdrom_watch.node = NULL;
> > }
> >
> > + unregister_rate_watch(be);
> > +
> > if (be->blkif) {
> > blkif_disconnect(be->blkif);
> > vbd_free(&be->blkif->vbd);
> > @@ -251,6 +256,10 @@ static int blkback_probe(struct xenbus_d
> >
> > err = xenbus_watch_path2(dev, dev->nodename, "physical-device",
> > &be->backend_watch, backend_changed);
> > +
> > + DPRINTK("blkback_probe called");
> > + DPRINTK("dev->nodename=%s/physical-device",dev->nodename);
> > +
> > if (err)
> > goto fail;
> >
> > @@ -266,7 +275,6 @@ fail:
> > return err;
> > }
> >
> > -
> > /**
> > * Callback received when the hotplug scripts have placed the
> > physical-device
> > * node. Read it and the mode node, and create a vbd. If the frontend is
> > @@ -283,8 +291,9 @@ static void backend_changed(struct xenbu
> > struct xenbus_device *dev = be->dev;
> > int cdrom = 0;
> > char *device_type;
> > + char name[TASK_COMM_LEN];
> >
> > - DPRINTK("");
> > + DPRINTK("backend_changed called");
> >
> > err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x",
> > &major, &minor);
> > @@ -322,6 +331,34 @@ static void backend_changed(struct xenbu
> > kfree(device_type);
> > }
> >
> > + /* gather information about QoS policy for this device. */
> > + err = blkback_name(be->blkif, name);
> > + if (err) {
> > + xenbus_dev_error(be->dev, err, "get blkback dev name");
> > + return;
> > + }
> > +
> > + err = xenbus_gather(XBT_NIL, dev->otherend,
> > + "tokens-rate", "%d", &be->blkif->reqrate,
> > + NULL);
> > + if(err){
> > + DPRINTK("%s xenbus_gather(tokens-min,tokens-rate) error",name);
> > + }else{
> > + if(be->blkif->reqrate <= 0){
> > + be->blkif->reqmin = 0 ;
> > + DPRINTK("%s tokens-rate == 0,no limit",name);
> > + }else{
> > + DPRINTK("%s
> > xenbus_gather(tokens-rate=%d)",name,be->blkif->reqrate);
> > + be->blkif->reqrate *= 2;
> > + be->blkif->reqmin = VBD_QOS_MIN_RATE_LIMIT;
> > + if(be->blkif->reqmin > be->blkif->reqrate){
> > + be->blkif->reqrate = be->blkif->reqmin;
> > + DPRINTK("%s reset default
> > value(tokens-rate=%d)",name,be->blkif->reqrate);
> > + }
> > + }
> > + }
> > + be->blkif->reqtime = jiffies;
> > +
> > if (be->major == 0 && be->minor == 0) {
> > /* Front end dir is a number, which is used as the handle. */
> >
> > @@ -414,6 +451,49 @@ static void frontend_changed(struct xenb
> >
> > /* ** Connection ** */
> >
> > +static void unregister_rate_watch(struct backend_info *be)
> > +{
> > + if (be->have_rate_watch) {
> > + unregister_xenbus_watch(&be->rate_watch);
> > + kfree(be->rate_watch.node);
> > + }
> > + be->have_rate_watch = 0;
> > +}
> > +
> > +static void rate_changed(struct xenbus_watch *watch,
> > + const char **vec, unsigned int len)
> > +{
> > +
> > + struct backend_info *be=container_of(watch,struct backend_info,
> > rate_watch);
> > + int err;
> > + char name[TASK_COMM_LEN];
> > +
> > + err = blkback_name(be->blkif, name);
> > + if (err) {
> > + xenbus_dev_error(be->dev, err, "get blkback dev name");
> > + return;
> > + }
> > +
> > + err = xenbus_gather(XBT_NIL,be->dev->otherend,
> > + "tokens-rate", "%d",
> > + &be->blkif->reqrate,NULL);
> > + if(err){
> > + DPRINTK("%s xenbus_gather(tokens-rate) error",name);
> > + }else{
> > + if(be->blkif->reqrate <= 0){
> > + be->blkif->reqmin = 0;
> > + DPRINTK("%s tokens-rate == 0,no limit",name);
> > + }else{
> > + DPRINTK("%s
> > xenbus_gather(tokens-rate=%d)",name,be->blkif->reqrate);
> > + be->blkif->reqrate *= 2;
> > + be->blkif->reqmin = VBD_QOS_MIN_RATE_LIMIT;
> > + if(be->blkif->reqmin > be->blkif->reqrate){
> > + be->blkif->reqrate = be->blkif->reqmin;
> > + DPRINTK("%s reset default
> > value(tokens-rate=%d)",name,be->blkif->reqrate);
> > + }
> > + }
> > + }
> > +}
> >
> > /**
> > * Write the physical details regarding the block device to the store, and
> > @@ -439,6 +519,14 @@ again:
> > if (err)
> > goto abort;
> >
> > + /*add by andrew for centos pv*/
> > + err = xenbus_printf(xbt, dev->nodename,"feature-flush-cache", "1");
> > + if (err){
> > + xenbus_dev_fatal(dev, err, "writing %s/feature-flush-cache",
> > + dev->nodename);
> > + goto abort;
> > + }
> > +
> > err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
> > vbd_size(&be->blkif->vbd));
> > if (err) {
> > @@ -469,11 +557,22 @@ again:
> > if (err)
> > xenbus_dev_fatal(dev, err, "ending transaction");
> >
> > + DPRINTK("xenbus_switch_to XenbusStateConnected");
> > +
> > err = xenbus_switch_state(dev, XenbusStateConnected);
> > if (err)
> > xenbus_dev_fatal(dev, err, "switching to Connected state",
> > dev->nodename);
> >
> > + unregister_rate_watch(be);
> > + err=xenbus_watch_path2(dev, dev->otherend, "tokens-rate",
> > +
> > &be->rate_watch,rate_changed);
> > + if (!err)
> > + be->have_rate_watch = 1;
> > + else
> > + xenbus_dev_fatal(dev, err, "watching tokens-rate",
> > + dev->nodename);
> > +
> > return;
> > abort:
> > xenbus_transaction_end(xbt, 1);
>
>
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
**************************************************
徐安（Andrew Xu）
部门 ：云快线 - 运营支撑中心 - 研发中心
手机 : 18910391796
E-mail：xu.an@xxxxxxxxxx
地址 ：北京市朝阳区酒仙桥东路1号M5楼
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