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From: Wei Yang <richardw.yang@linux.intel.com>
To: quintela@redhat.com, dgilbert@redhat.com
Cc: qemu-devel@nongnu.org, Wei Yang <richardw.yang@linux.intel.com>
Subject: [PATCH v2 0/6] migration/multifd: a new mechanism for send thread sync
Date: Sat, 26 Oct 2019 08:45:14 +0800	[thread overview]
Message-ID: <20191026004520.5515-1-richardw.yang@linux.intel.com> (raw)

Current send thread could work while the sync mechanism has some problem:

  * has spuriously wakeup
  * number of channels_ready will *overflow* the number of real channels

The reason is:

  * if MULTIFD_FLAG_SYNC is set in the middle of send thread running, there
    is one more spurious wakeup
  * if MULTIFD_FLAG_SYNC is set when send thread is not running, there is one
    more channels_ready be triggered

To solve this situation, one new mechanism is introduced to synchronize send
threads. The idea is simple, a new field *sync* is introduced to indicate a
synchronization is required.

---
v2: rebase on latest code

Wei Yang (6):
  migration/multifd: move Params update and pages cleanup into
    multifd_send_fill_packet()
  migration/multifd: notify channels_ready when send thread starts
  migration/multifd: use sync field to synchronize send threads
  migration/multifd: used must not be 0 for a pending job
  migration/multifd: use boolean for pending_job is enough
  migration/multifd: there is no spurious wakeup now

 migration/ram.c | 74 +++++++++++++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 27 deletions(-)

-- 
2.17.1



             reply	other threads:[~2019-10-26  1:24 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-26  0:45 Wei Yang [this message]
2019-10-26  0:45 ` [PATCH v2 1/6] migration/multifd: move Params update and pages cleanup into multifd_send_fill_packet() Wei Yang
2019-11-19 10:57   ` Juan Quintela
2019-11-29  8:30     ` Wei Yang
2019-10-26  0:45 ` [PATCH v2 2/6] migration/multifd: notify channels_ready when send thread starts Wei Yang
2019-10-26  0:45 ` [PATCH v2 3/6] migration/multifd: use sync field to synchronize send threads Wei Yang
2019-10-26  0:45 ` [PATCH v2 4/6] migration/multifd: used must not be 0 for a pending job Wei Yang
2019-10-26  0:45 ` [PATCH v2 5/6] migration/multifd: use boolean for pending_job is enough Wei Yang
2019-10-26  0:45 ` [PATCH v2 6/6] migration/multifd: there is no spurious wakeup now Wei Yang
2019-12-16  2:36 ` [PATCH v2 0/6] migration/multifd: a new mechanism for send thread sync Wei Yang

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