Hi,
relying on DM is not advisable since this is yet another layer that
breaks write barriers, plus it kills portability to non-linux OS.
btw:
It would be cool if a block shaping patch finally made it in the Xen
mainline, since the last one that was submitted in 2009 was apparently
forgotten...
Regards,
Florian
2011/6/21 Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>:
> 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? There is a xen-blkback in 3.0-rc4, can you rebase
> it against that please.
>
> What is the patch solving? Why can't it be done with dm-ioband?
>
>> 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
>
--
the purpose of libvirt is to provide an abstraction layer hiding all
xen features added since 2006 until they were finally understood and
copied by the kvm devs.
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