Re: [Qemu-devel] [RFC PATCH RDMA support v4: 09/10] check for QMP string and bypass nonblock() calls

[Paolo Bonzini]

Il 18/03/2013 04:19, address@hidden ha scritto:
> From: "Michael R. Hines" <address@hidden>
> 
> Since we're not using TCP anymore, we skip these calls.
> 
> Also print a little extra text while debugging, like "gbps"
> which is helpful to know how the link is being utilized.
> 
> Signed-off-by: Michael R. Hines <address@hidden>
> ---
>  include/migration/migration.h |    3 +++
>  migration.c                   |   19 +++++++++++++------
>  2 files changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/include/migration/migration.h b/include/migration/migration.h
> index bb617fd..88ab5f6 100644
> --- a/include/migration/migration.h
> +++ b/include/migration/migration.h
> @@ -20,6 +20,7 @@
>  #include "qemu/notify.h"
>  #include "qapi/error.h"
>  #include "migration/vmstate.h"
> +#include "migration/rdma.h"
>  #include "qapi-types.h"
>  
>  struct MigrationParams {
> @@ -102,6 +103,7 @@ uint64_t xbzrle_mig_bytes_transferred(void);
>  uint64_t xbzrle_mig_pages_transferred(void);
>  uint64_t xbzrle_mig_pages_overflow(void);
>  uint64_t xbzrle_mig_pages_cache_miss(void);
> +uint64_t delta_norm_mig_bytes_transferred(void);

Please add the protocol under the
>  
>  /**
>   * @migrate_add_blocker - prevent migration from proceeding
> @@ -122,6 +124,7 @@ int xbzrle_encode_buffer(uint8_t *old_buf, uint8_t 
> *new_buf, int slen,
>  int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
>  
>  int migrate_use_xbzrle(void);
> +void *migrate_use_rdma(QEMUFile *f);

Perhaps you can add a new function to QEMUFile send_page?  And if it
returns -ENOTSUP, proceed with the normal is_dup_page + put_buffer.  I
wonder if that lets use remove migrate_use_rdma() completely.

Also, if QEMUFileRDMA is moved to rdma.c, the number of public and
stubbed functions should decrease noticeably.  There is a patch on the
list to move QEMUFile to its own source file.  You could incorporate it
in your series.

>  int64_t migrate_xbzrle_cache_size(void);
>  
>  int64_t xbzrle_cache_resize(int64_t new_size);
> diff --git a/migration.c b/migration.c
> index 185d112..634437a 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -15,6 +15,7 @@
>  
>  #include "qemu-common.h"
>  #include "migration/migration.h"
> +#include "migration/rdma.h"
>  #include "monitor/monitor.h"
>  #include "migration/qemu-file.h"
>  #include "sysemu/sysemu.h"
> @@ -77,6 +78,8 @@ void qemu_start_incoming_migration(const char *uri, Error 
> **errp)
>  
>      if (strstart(uri, "tcp:", &p))
>          tcp_start_incoming_migration(p, errp);
> +    else if (strstart(uri, "rdma:", &p))
> +        rdma_start_incoming_migration(p, errp);
>  #if !defined(WIN32)
>      else if (strstart(uri, "exec:", &p))
>          exec_start_incoming_migration(p, errp);
> @@ -118,10 +121,11 @@ static void process_incoming_migration_co(void *opaque)
>  void process_incoming_migration(QEMUFile *f)
>  {
>      Coroutine *co = qemu_coroutine_create(process_incoming_migration_co);
> -    int fd = qemu_get_fd(f);
> -
> -    assert(fd != -1);
> -    socket_set_nonblock(fd);
> +    if(!migrate_use_rdma(f)) {
> +        int fd = qemu_get_fd(f);
> +        assert(fd != -1);
> +        socket_set_nonblock(fd);

Is this because qemu_get_fd(f) returns -1 for RDMA?  Then, you can
instead put socket_set_nonblock under an if(fd != -1).

> +    }
>      qemu_coroutine_enter(co, f);
>  }
>  
> @@ -404,6 +408,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
>  
>      if (strstart(uri, "tcp:", &p)) {
>          tcp_start_outgoing_migration(s, p, &local_err);
> +    } else if (strstart(uri, "rdma:", &p)) {
> +        rdma_start_outgoing_migration(s, p, &local_err);
>  #if !defined(WIN32)
>      } else if (strstart(uri, "exec:", &p)) {
>          exec_start_outgoing_migration(s, p, &local_err);
> @@ -545,8 +551,9 @@ static void *migration_thread(void *opaque)
>              max_size = bandwidth * migrate_max_downtime() / 1000000;
>  
>              DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
> -                    " bandwidth %g max_size %" PRId64 "\n",
> -                    transferred_bytes, time_spent, bandwidth, max_size);
> +                    " bandwidth %g (%0.2f mbps) max_size %" PRId64 "\n",
> +                    transferred_bytes, time_spent, 
> +                    bandwidth, Gbps(transferred_bytes, time_spent), 
> max_size);
>              /* if we haven't sent anything, we don't want to recalculate
>                 10000 is a small enough number for our purposes */
>              if (s->dirty_bytes_rate && transferred_bytes > 10000) {
> 

Otherwise looks good.