Table of Contents

VM-I/O concurrency project for FreeBSD 10.0-Release

This page documents proposed task-list for improving VM subsystem and I/O stack concurrency and performance to be delivered in FreeBSD 10.0-Release. Everyone is encouraged in modifying the page adding more tasks, submitting his name under projects to be completed and offer guidance, review and testing for any of these items.

Tasklist targeted for FreeBSD 10.0-R

Task Responsible Last update Scope (Effort) Status / % complete Location of branch
Multi-digit trie and use it for resident and cached pages within vm_objects attilio 03/17/2013 Completed (r248449 et al.)
Unmapped I/O jeff, kib 03/18/2013 Completed (r246713,248280 et al.)
radix tree for buf cache jeff 04/29/2013 Completed
vfs_bio.c mtx contention bqlock jeff 03/10/2013 Completed
Fine-grained locking for pv lists alc 06/03/2013 FineGrainedPvListsPmap 75% Complete (r235695, r237228, r237290, r237551, r237592)
Shared locking for vm_objects lock attilio, alc 12/21/2012 In progress svn://svn.freebsd.org/base/user/attilio/vmobj-readlock/
Fine-grained locking for active and inactive page queues alc, kib 12/21/2012 In progress https://www.kib.kiev.ua/git/gitweb.cgi?p=deviant2.git;a=shortlog;h=refs/heads/nofault
Fine-grained locking for free pages queue alc, jeff 12/21/2012 In progress
Improved kernel NUMA support jeff, alc, attilio 12/21/2012 In progress

Tasklist targeted after FreeBSD 10.0-R

Task Responsible Last update Scope (Effort) Status / % complete Location of branch
Unmapped I/O exploiting by non-critical CAM drivers ??? 12/21/2012
Implement userland NUMA support jeff, alc, attilio 12/21/2012 Unstarted
GEOM multi-threading dispatching mav 10/22/2013 Completed (r256880+)
Revisit GEOM BIOs copy overhead pjd 12/21/2012 Unstarted
SMP CAM/CAM multithreading - Fix CAM consumers to not assume GEOM single-threading mav 10/21/2013 Completed (r256843+)
so_snd/so_rcv contention ??? 03/10/2013 Unstarted
umtx/pthread overhaul attilio, davide 03/22/2013 Unstarted
unmapped mbufs jeffr NA/NA Unstarted

Task breakdowns

Shared locking for vm_objects lock

Task Responsible Last update Scope (Effort) Status / % complete Location of branch
Rewrite the page struct/data protection mechanism attilio 06/04/2013 2 awaiting reviews svn://svn.freebsd.org/base/user/attilio/vmobj-readlock/

Additional notes

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