From: Scott Cheloha <cheloha@linux.vnet.ibm.com>
To: qemu-devel@nongnu.org
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>,
Juan Quintela <quintela@redhat.com>
Subject: [PATCH v2 0/2] migration: faster savevm_state_handler_insert()
Date: Thu, 17 Oct 2019 15:59:51 -0500 [thread overview]
Message-ID: <20191017205953.13122-1-cheloha@linux.vnet.ibm.com> (raw)
The savevm_state.handlers queue of SaveStateEntry objects is a
priority queue with an O(n) insertion cost. This is makes startup
extremely slow when a VM has many such objects to register. For
instance, a ppc64 VM with a large (8T+) maxmem needs to register tens
of thousands of SaveStateEntry handlers: startup for these VMs is
glacial.
If we track insertion points within the priority queue we can make
savevm_state_handler_insert() a constant-time operation with little
change to the module's code. Startup times for VMs with many handlers
are dramatically improved as a result.
Changes since v1:
* Split patch 1 into 2 patches.
Scott Cheloha (2):
migration: add savevm_state_handler_remove()
migration: savevm_state_handler_insert: constant-time element
insertion
migration/savevm.c | 35 ++++++++++++++++++++++++++++++-----
1 file changed, 30 insertions(+), 5 deletions(-)
--
2.23.0
next reply other threads:[~2019-10-17 21:02 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-17 20:59 Scott Cheloha [this message]
2019-10-17 20:59 ` [PATCH v2 1/2] migration: add savevm_state_handler_remove() Scott Cheloha
2019-12-04 16:43 ` Dr. David Alan Gilbert
2020-01-08 19:07 ` Juan Quintela
2019-10-17 20:59 ` [PATCH v2 2/2] migration: savevm_state_handler_insert: constant-time element insertion Scott Cheloha
2019-10-18 8:16 ` Dr. David Alan Gilbert
2019-10-18 8:34 ` Laurent Vivier
2019-10-18 9:43 ` Dr. David Alan Gilbert
2019-10-18 16:38 ` Michael Roth
2019-10-18 17:26 ` Dr. David Alan Gilbert
2019-10-21 7:33 ` David Gibson
2019-10-19 10:12 ` David Gibson
2019-10-21 8:14 ` Dr. David Alan Gilbert
2019-11-20 21:48 ` Scott Cheloha
2019-12-04 16:49 ` Dr. David Alan Gilbert
2019-12-04 22:28 ` David Gibson
2019-12-04 16:47 ` Dr. David Alan Gilbert
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