Operating Systems: Three Easy Pieces

Errata and Book News

Here is a list of problems found and fixed in the book, as well as book news. Thanks so much to all of you for your help! Check out the book preface for more specific acknowledgements.

v1.10 09/28/23: Slowly moving chapters to version 1.10 - only small changes really, so don't worry if you have 1.0 or 1.01.
v1.01 08/08/20: From now on, see the OSTEP typos page for this information.
v1.01 07/06/20: Added new Security chapters by Peter Reiher (UCLA) to the main page. These are included only on the webpage and not in printed form or in the entire PDF at this point.
v1.01 06/28/20 (Helen Gaiser): missing header in threads-sema homework
v1.01 06/28/20 (Ngu Q. Truong): fix to simulation homework in cpu-api
v1.01 06/25/20: new simple simulation homework in cpu-api
v1.01 06/23/20 (Prabhsimrandeep Singh): bug in LFS simulator in file-lfs
v1.01 06/13/20 (Benjamin Wilhelm @ Konstanz): bug in vm-segmentation homework
v1.01 05/20/20 (Jeet Pavani): typo in README in threads-lock/README.md
v1.01 04/26/20 (Rick Perry): bad javascript in web pages
v1.01 02/27/20 (Axel Trompler @ KIT): url typo in threads-sema
v1.01 01/20/20 (Gavin Inglis @ Notre Dame): typo in cpu-sched-lottery
v1.01 01/19/20 (Sameer Punjal): typo in threads-locks-usage
v1.01 01/19/20 (Justinas Petuchovas): typo in
v1.01 01/02/19 (Shawn Ge): typo in file-disks
v1.01 01/02/19 (Justinas Petuchovas): typo in intro
v1.01 11/26/19 (Diego Oleiarz @ FaMAF UNC): code nit in threads-cv
v1.01 10/30/19 (Yufeng Zhang @ UCLA): thread not process in threads-locks
v1.01 10/30/19 (Marco Pedrinazzi @ Universita Degli Studi Di Milano): typo in vm-intro
v1.01 07/13/19 (Rita Pia Folisi): typo in file-intro
v1.01 07/03/19 (Patrizio Palmisano): typo in threads-bugs
v1.01 06/11/19 (Dawn Flood): better first two pics in file-journaling
v1.01 06/04/19: reformatting updates to vm-smalltables
v1.01 06/04/19: reformatting updates to vm-paging , plus new aside as suggested by Jidong Xiao (Boise State)
v1.01 06/03/19: reformatting updates to vmm-intro, vm-mechanism
v1.01 06/02/19: reformatting updates to threads-cv, threads-locks-usage
v1.01 05/30/19: reformatting updates to dist-intro, file-integrity, file-ffs, threads-monitors, threads-events
v1.01 05/29/19: reformatting updates to cpu-sched, cpu-sched-mlfq, dist-afs
v1.01 05/21/19: reformatting updates to dialogue-threeeasy, dialogue-persistence, dialogue-concurrency, dialogue-monitors, vm-dialogue, dialogue-vmm, dialogue-distribution, dist-dialogue, dialogue-vm, cpu-dialogue, file-dialogue, dialogue-virtualization, dialogue-labs, lab-projects-systems, lab-projects-xv6
v1.01 05/20/19 (Chien-Chung Shen @ Delaware): updated Linux lock ordering in threads-bugs
v1.01 05/20/19 (Hao Liu): clarify PC in cpu-intro
v1.01 05/20/19 reformat of intro
v1.01 05/19/19 (Hyrum Carroll @ Columbus State): code suggestion in vm-intro
v1.01 05/19/19 (KyoungSoo Park @ KAIST): typo in file-disks
v1.01 05/19/19 (KyoungSoo Park @ KAIST): typo in threads-bugs
v1.01 05/19/19 (KyoungSoo Park @ KAIST): typo in vm-complete
v1.01 05/18/19: Bigger diagrams in vm-freespace
v1.01 05/18/19 (Louie Lu and Hao Liu): bad C form in vm-freespace
v1.01 05/18/19 (Eric Kleinberg): suggestion for threads-dialogue
v1.01 05/18/19 (Greggory Van Dycke): typo in file-device
v1.01 05/18/19: reformatting and section on thread throttling in threads-sema
v1.01 05/18/19 (Perry Kivolowitz): rule of thumb for semaphores in threads-sema
v1.01 05/17/19 (Nishin Shouzab): Wrong includes in lab-tutorial
v1.01 05/17/19 (Matthias St. Pierre): Added footnote on lock modularity in threads-sema
v1.01 05/17/19: Added a bit more to cpu-api , particularly to some recent relevant citations
v1.01 05/17/19 (Stephen Schaub): typo in cpu-sched-lottery , suggestions in file-raid
v1.01 05/17/19 (Chien-Chung Shen @ Delaware): typo in file-intro
v1.01 05/16/19 (Paul Hanzlik and Jing Liu): fixed bibtex on ostep.org
v1.01 05/16/19 (Muhammad Yasoob Ullah Khalid): typo in file-implementation cites
v1.01 05/15/19 (Nan Xiao): typo in cpu-sched-multi
v1.01 05/14/19 (Nan Xiao): typo in cpu-sched-lottery
v1.01 05/14/19 (Bart Miller): clearer history of P/V in threads-sema
v1.01 05/10/19 (Bill Yang): clarification in threads-sema
v1.01 05/08/19 (Chien-Chung Shen @ Delaware): reword in threads-bugs
v1.01 05/06/19 (Shivaram Venkataraman and Jaeyoung Cho @ SKKU): some clarification in vm-segmentation (which led to more general additional material)
v1.01 05/04/19 (Chien-Chung Shen @ Delaware): typo in cpu-mechanisms
v1.01 05/04/19 (Dominic White): typo in cpu-sched-lottery
v1.01 05/04/19 (Jason Waterman @ Vassar): bad cite in vm-complete
v1.01 05/04/19 (Chien-Chung Shen @ Delaware): suggested reword in threads-locks
v1.01 05/04/19 (Chien-Chung Shen @ Delaware): typos in lab-tutorial
v1.01 04/23/19 (Chien-Chung Shen @ Delaware): typo in threads-api
v1.01 04/17/19 (Mohamed Omran @ GUST): code typo in threads-sema
v1.01 04/16/19 (Chien-Chung Shen @ Delaware): nit in threads-intro
v1.01 04/08/19 (Ethan Wood): citation fix in cpu-sched-lottery
v1.01 03/28/19 (Tobi Popoola): bug fix in fsck.py
v1.01 03/02/19 (Dylan Kaplan): particularly not particular in vm-tlbs
v1.01 03/02/19 (Chien-Chung Shen @ Delaware): nit in file-implementation
v1.01 03/02/19 (Andrei Bozantan): clarify niceness oddity/not in cpu-sched-lottery
v1.01 03/01/19 (Marcel van der Holst): bad link in file-implementation, file-lfs, file-journaling, file-ssd
v1.01 02/28/19 (Andrew Moss): typo in vm-complete
v1.01 02/28/19 (Andrew Moss): typo in threads-locks
v1.01 02/26/19 (John McEachen @ NPS): typo in cpu-sched-lottery equation; also re-typesetting for better readability in general.
v1.00 10/12/18 (Louie Lu): fix to homework multi.py
v1.00 08/29/18: Version 1.0 release. Adds everything you see in 0.92 below, plus many other things, including many homeworks (including SSD simulator, multi-CPU scheduling simulator, NFS trace analysis, more security information throughout (in MLFQ scheduling, Linux VM ASLR discussion, tiny bit on Meltdown/Spectre, file permissions/access control lists, discussion of TOCTTOU attacks, etc.), more about Linux CFS scheduler, more about Linux VM, changed VMS chapter into complete VM chapter with Linux details (and VMS), better discussion of open file table vs. descriptors, better devices diagram, key terms added at the end of some chapters, more citations to important work, more citations to our own work, better formatting so as not to use too many pages, etc. Update to printed books too. Latest full electronic book available at Gumroad (and, you always get those updates for free).
v0.92 08/29/18 (Yuanyuan Chen): small change to file-nfs
v0.92 08/29/18 (Scott Lee @ UCLA): typo in file-integrity
v0.92 08/24/18: added separation between time slice and allotment per queue level to homework in cpu-sched-mlfq
v0.92 08/24/18: added notion of user and other stuff to cpu-api
v0.92 08/24/18: added permission/ACL discussion to file-intro
v0.92 08/24/18: added homework to dist-nfs
v0.92 08/23/18: some revision to file-device
v0.92 08/23/18: added homework to file-ssd
v0.92 08/20/18: added homework to cpu-sched-multi
v0.92 08/16/18: added note on security to cpu-sched-mlfq
v0.92 08/16/18: added homework to threads-sema
v0.92 08/14/18 (Zeyuan Hu): typos in threads-events, file-implementation, file-lfs
v0.92 08/14/18 (Neil Perry): typos in vm-smalltables, threads-locks, threads-bugs, dialogue-concurrency, file-lfs
v0.92 08/14/18: added Vnode/VFS side bar in dist-nfs
v0.92 08/14/18 (Chien-Chung Shen @ Delaware): detailed citation in vm-api
v0.92 08/14/18: added more details about FTL size reduction and summary of terms to file-ssd
v0.92 08/14/18 (Youjip Won @ Hanyang): added much better discussion of file descriptors, open file table, and fork/dup, to file-intro
v0.92 08/08/18 (Kemal Bicakci): typo in file-implementation
v0.92 08/08/18 (Emil Hessman): typos in threads-bugs, file-ssd, vm-tlbs, vm-beyondphys-policy, dist-afs
v0.92 08/08/18: slight update to add citations to threads-intro
v0.92 07/05/18: added homework to file-journaling
v0.92 06/11/18 (Stephen Bye): typos in file-disks, threads-events
v0.92 06/04/18 (Hilmar Gustafsson @ Aalborg): typo in vm-mechanism
v0.92 06/04/18 (Jhih-Cheng Luo): typo in threads-sema
v0.92 06/04/18 (Zeyuan Hu @ Texas): typo and suggestion in file-ssd
v0.92 05/16/18 (Stephen Bye): rename variable in cpu-api
v0.92 05/10/18 (James Earley): typo in file-ssd
v0.92 04/25/18 (Tianxia Bai): error in switch-merge example in file-ssd
v0.92 04/19/18 (C.J. Stanbridge @ Memorial U. in Newfoundland): 'PDE Entry' not 'PDE' in vm-smalltables
v0.92 04/12/18 (Nicholas Mandal): predetermined not pre-determined in file-device
v0.92 03/06/18 (Darby Asher Noam Haller): bitwise not logical OR in vm-paging
v0.92 02/26/18 (Marcel van der Holst): typo in vm-beyondphys
v0.92 02/12/18 (Neil Perry): typo in vm-segmentation
v0.92 02/10/18 (Robert Ordonez @ Southern Adventist): start graphs at actual 0 cpu-sched-mlfq
v0.92 01/24/18 (Mohamed Omran @ GUST): introduce acronym more carefully in cpu-mechanisms
v0.92 12/17/17 (Yuanyuan Chen): typo in dist-afs
v0.92 11/28/17 (Joshua Carpenter @ NCSU): typo in file-journaling
v0.92 11/04/17 (Sam Kelly): many small fixes in threads-api, vm-api, threads-locks, threads-locks-usage, file-ssd, vm-beyondphys-policy, vm-intro, vm-smalltables
v0.92 11/04/17 (Eric Johansson): compiler flag in intro code example
v0.92 11/03/17 (Peter Peterson @ Minnesota): suggestions for file-lfs
v0.92 11/03/17 (Dakota Crane @ Washington-Tacoma): suggested GNU shout out in intro
v0.92 11/03/17 (Alistair Martin): fixes to homework in threads-locks
v0.92 11/02/17 (Antonella Bernobich @ UoPeople): host of typos - gasp! - in threads-api, threads-sema, thread-bugs, thread-events, file-disks, file-intro, file-journaling, file-integrity, file-dialogue, dist-intro, dist-nfs, dist-afs
v0.92 11/02/17 (Rohan Puri): typo in threads-sema
v0.92 10/31/17 (Yifan Hao): better AMAT definition in vm-beyondphys-policy
v0.92 10/31/17: inserted file-ssd chapter into main flow, renumbered chapters as appropriate
v0.92 10/31/17 (Waciuma Wanjohi): answer to footnote in vm-mechanism
v0.92 10/31/17 (Manu Awasthi): citation fix for ZFS (throughout), small fix in file-journaling
v0.92 10/18/17 (Dan Tsafrir @ Technion): clarified definition in cpu-sched
v0.92 10/01/17 (Robert Ordonez @ Southern Adventist): mistaken in vm-intro homework
v0.92 09/26/17 (Robert Ordonez @ Southern Adventist): oversight in malloc homework
v0.92 09/21/17 (Giovanni Lagorio @ DIBRIS): suggestions for lecturer notes in intro
v0.92 09/14/17 (Ahmad Jarara): typo in homework in file-ffs
v0.92 09/07/17 (Eric Freudenthal @ UTEP): rephrase in cpu-intro
v0.92 09/07/17 (Jason Waterman @ Vassar): typo in cites of cpu-sched-mlfq
v0.92 07/31/17 (Stefan Dekanski): typo in file-intro
v0.92 07/31/17 (Spencer Harston @ Weber State): url problems in file-disks
v0.92 07/18/17 (Michael Wu): typos in intro
v0.92 06/22/17: added homeworks to file-integrity
v0.92 06/16/17: added homework to file-lfs
v0.92 06/07/17: added homework to vm-intro
v0.92 06/07/17 (Looserof): code fix in cpu-api
v0.92 06/06/17 (Chien-Chung Shen @ Delaware): improvements to threads-locks
v0.92 06/06/17 (Peter Peterson @ Minnesota): some fixes to dist-afs
v0.92 06/06/17 (Sam Noh): Some rewording in threads-cv for clarity
v0.92 06/05/17 (Natasha Stopa): suggested fix to wording around spinlock fairness in threads-locks
v0.92 06/05/17 (Marco Guazzone @ University of Piemonte Orientale): bug in code in file-intro
v0.92 06/05/17 (Brandon Harshe): replace Mac OS X with macOS or more generic term (many chapters)
v0.92 06/05/17 (Ben Kushigian): code bug in threads-api
v0.92 05/22/17 (Yubin Ruan): rewording in file-journaling
v0.92 05/20/17 (Yubin Ruan): better citations in file-lfs
v0.92 05/15/17 (Danilo Bruschi @ Universita Degli Studi Di Milano): Correction to file-implementation
v0.92 05/13/17 (Michael Machtel @ Hochschule Konstanz): Typo in threads-cv homework
v0.92 04/30/17 (Tyler Couto): Typo in vm-tlbs
v0.92 04/07/17 (Nadeem Shaikh): Typo in thread-intro homework README
v0.92 12/07/16: CMU clarification
v0.92 12/01/16 (Tong He): typo in threads-api
v0.92 11/16/16 (Glenn Bruns @ CSU Monterey Bay): rewording in in file-device
v0.92 10/05/16 (Scott Catlin): text suggestion in cpu-sched-mlfq
v0.92 10/05/16 (Natasha Stopa and Dennis Zhou): found/fixed bug in mlfq.py homework
v0.92 10/05/16 (P. Kivolowitz and R. Ordonez): small bugs in vm-mechanism
v0.92 09/21/16 (Andrew Mahler): typo in vm-paging
v0.92 09/21/16 (Alex Curtis): typo in code in dist-intro
v0.92 09/13/16: Added missing cite in dist-intro
v0.92 08/27/16 (Pieter Kockx): Typo in intro
v0.92 08/19/16 (Aaron Gember @ Colgate): Typos in file-intro, cpu-api, cpu-mechanisms
v0.92 08/04/16: Added homework to chapter file-ffs , typo in vm-smalltables
v0.91 07/20/16: print and electronic editions updated to latest; v0.91 finalized
v0.91 07/12/16 (Thanu Pillai): small fix in file-journaling
v0.91 07/12/16 (Peter Peterson @ Minnesota): typo in threads-dialogue
v0.91 07/06/16: Added homework to chapter vm-beyondphys
v0.91 07/05/16: Added homework to chapter threads-api
v0.91 07/05/16: Added homework to chapter threads-bugs ; added bit on priority inversion to threads-locks
v0.91 06/20/16: Added details on priority inversion to threads-locks
v0.91 06/20/16: Added homework to chapter threads-cv
v0.91 06/20/16 (Jia-Shen Boon): typos in vm-mechanism, vm-beyondphys-policy, dialogue-distribution, dist-intro, file-implementation
v0.91 06/09/16 (Chien-Chung Shen @ Delaware): improvements to cpu-mechanisms
v0.91 06/09/16 Antonella Bernobich @ UoPeople): typos in vm-api, vm-freespace
v0.91 06/09/16 (Manu Awasthi @ Samsung): fixed citation in cpu-intro
v0.91 06/09/16 (Jose Cruz @ U. Portugal): added third parameter in file-intro
v0.91 06/09/16 (Laura Xu): bug in simulator in threads-locks
v0.91 06/09/16 (Peter Peterson @ Minnesota): typo in threads-locks-usage, vm-tlbs
v0.91 06/09/16 (John Komenda): typo in file-ssd
v0.91 06/09/16 (Alex Curtis): typo in file-lfs
v0.91 06/09/16 (Leonardo Medici @ U. Milan): typo in file-device
v0.91 06/09/16 (Sam Kelly): typo in vm-api
v0.91 05/31/16: Added a discussion on why threads are useful to threads-intro
v0.91 05/11/16: Updated pet status in file-intro
v0.91 05/02/16 (John Komenda): typos in file-integrity and dist-intro
v0.91 05/02/16 (Cheng Su): typo in pic in file-ssd
v0.91 04/28/16 (Chien-Chung Shen @ Delaware): typo in vm-freespace
v0.91 04/27/16 (Aashrith H Govindraj @ USF): typo in dist-intro
v0.91 02/29/16 (Antonella Bernobich @ UoPeople): typos in vm-api
v0.91 02/29/16 (Constantinos Georgiades): typos in deprecated threads-monitors
v0.91 02/29/16 (Fang Zheng @ IBM): typo in vm-beyondphys-policy
v0.91 02/12/16 (Lanyue Lu): typo in ticket lock code in threads-locks
v0.91 02/08/16 (Constantinos Georgiades): typo in file-implementation
v0.91 02/08/16 (Roger Wattenhofer @ ETH): fixes in vm-segmentation, vm-paging, file-intro, file-ssd
v0.91 02/01/16 (Constantinos Georgiades): typo in threads-bugs
v0.91 01/28/16 (Simon Pratt @ Waterloo): figure reference in vm-tlbs homework
v0.91 01/27/16 (ZiHan Zheng @ USTC): correction to pipe example code in cpu-api
v0.91 01/26/16 (Peter Peterson @ Minnesota): typo in lab-tutorial
v0.91 01/25/16 (Peter Peterson @ Minnesota): rewording in cpu-sched
v0.91 01/25/16 (Mattia Monga @ U. Milan): clarification in homework README of cpu-intro
v0.91 01/24/16 (Fangjun Kuang @ U. Stuttgart): typo in threads-locks-usage
v0.91 01/20/16 (Michael Walfish @ NYU): fixes in file-lfs, file-implementation
v0.91 01/19/16 (Peter Peterson @ Minnesota): typos in cpu-intro homework
v0.91 01/15/16 (Sankaralingam Panneerselvam): typos in cpu-api, threads-locks, file-ffs, file-lfs . Also inspired new material in file-ffs
v0.91 01/12/16 (Glen Granzow): typos in vm-vax, threads-locks-usage, threads-cv, threads-bugs, threads-events, file-disks, file-raid, file-intro, file-implementation, file-journaling, file-lfs, file-integrity, dist-intro, dist-nfs . Wow!
v0.91 01/12/16 (Demic Delic): citation url in file-integrity
v0.91 01/12/16 (Christian Stober): typo in vm-api
v0.91 01/05/16 (Jason MacLafferty @ Southern Adventist): typo in README for threads-intro, threads-locks
v0.91 01/04/16 (Patel Pratyush Ashesh @ BITS-Pilani): typos in file-lfs, file-integrity, dist-intro
v0.91 12/27/15 (Patel Pratyush Ashesh @ BITS-Pilani): bug in process-run.py , typo in file-intro , typo in dialogue-monitors
v0.91 12/20/15 (Thomas Scrace): typo in cpu-mechanisms
v0.91 12/14/15 (Pavle Kostovic): typo in dist-nfs
v0.91 12/09/15 Small update to cpu-sched
v0.91 12/09/15 (Jackson Haenchen @ Texas): typo in threads-bugs
v0.91 11/24/15 (Vikas Goel, Abhinav Mehra): bug in raid.py
v0.91 11/24/15 (Vikas Goel, Katherine Dudenas, Abhinav Mehra): correctly names SCAN vs. C-SCAN(!) in file-disks
v0.91 11/09/15 (Glenn Bruns @ CSU Monterey Bay): rewording in in file-implementation
v0.91 10/23/15 (Glenn Bruns @ CSU Monterey Bay): rewording in in threads-sema
v0.91 10/23/15 (Alex Zhao @ U. Colorado at Colorado Springs): rewording in in threads-locks
v0.91 10/23/15 (Robert Ordonez @ Southern Adventist): typo in threads-locks
v0.91 10/18/15 (Arek Bulski): typo in file-ssd
v0.91 10/18/15 (Stanley Chan @ RIT): typo in update to this file
v0.91 10/17/15 (Jiawen Bao): bug in ticket lock code in threads-locks
v0.91 10/17/15 (Arek Bulski): typo in file-integrity
v0.91 10/16/15 (Ilya Oblomkov): bug in process-run.py
v0.91 10/10/15 (Robert Ordonez @ Southern Adventist): rewording in vm-beyondphys-policy
v0.91 10/10/15 (Katie Coyle @ Georgia Tech): Typo in cpu-sched-multi
v0.91 10/08/15 (Jagannathan T. Eachambadi): bug in lottery.py
v0.91 10/08/15 (Song Jiang @ Wayne State): typos in file-ffs , file-lfs
v0.91 09/30/15: new chapter on flash-based SSDs now available in beta
v0.91 09/23/15 (Manav Batra @ IIIT-Delhi): typo in vm-paging
v0.91 09/22/15 (Glen Bruns @ CSU Monterey Bay): typo in vm-segmentation
v0.91 09/22/15 (Katie Coyle @ Georgia Tech): Typo in threads-intro
v0.91 09/09/15 (Katie Coyle @ Georgia Tech): Typo in dialogue-virtualization
v0.91 09/03/15 (Yudong Sun): Typo in file-lfs
v0.91 09/01/15 (Mart Oskamp): Fixed Dutch interpretation of P/V in (no surprise) chapter on threads-sema
v0.91 08/31/15 (Robert Ordonez @ Southern Adventist): Number don't itemize in cpu-api and everywhere else
v0.91 08/19/15 (Satish Chebrolu): Typos in threads-api
Homework 04/29/15 (Dorian Arnold): Bug in raid.py with timing mode
v0.91 04/15/15: Small update to vm-freespace
v0.91 04/13/15 (Glen Granzow @ College of Idaho): typos in threads-locks
v0.91 04/05/15 (Sandeep Ummadi): typo in threads-locks-usage
v0.90 03/31/15: v0.90 RELEASED: Updates to many chapters, resulting in new version 0.90
03/25/15 (Teri Zhao): bug in homework vsfs.py when out of inodes
03/17/15 (AmirBehzad Eslami): typos and suggestions in mystery-chapter
03/12/15 (Jakob Olandt): typo in threads-bugs
03/09/15 (Glen Granzow @ College of Idaho): typos in vm-beyondphys-policy and vm-beyondphys
03/09/15 (Perry Kivolowitz): bug in file-device
03/04/15 (Dheeraj Shetty @ NC State): awkward phrasing in vm-smalltables
03/04/15 (Jingxin Li): bug in table in threads-intro
03/03/15 (Angela Demke Brown @ Toronto): bug in vm-paging homework script
03/02/15 (Glen Granzow @ College of Idaho): typo in vm-freespace homeowork
02/25/15 (Glen Granzow @ College of Idaho): typos and fixes in vm-paging and vm-tlbs
02/25/15 (Perry Kivolowitz): a few small things in threads-locks
02/25/15 (Perry Kivolowitz): variable naming in threads-api
02/23/15 (Perry Kivolowitz): wording change and extra commentary on interrupt masking in threads-locks
02/20/15 (Michael Walfish @ NYU): added discussion on partial orderings in threads-bugs
02/19/15 (Michael Walfish @ NYU): typographical fix and bug in threads-bugs
02/17/15 (Glen Granzow @ College of Idaho): typo in cpu-sched homework, and bug in priority boost graph in cpu-sched-mlfq
02/17/15 (Michael Walfish @ NYU): fixes in threads-cv and threads-locks-usage as well as the suggestion to renumber tables and figures in a consistent way (a change that will happen slowly to all chapters with tables).
02/16/15 (Perry Kivolowitz): suggested clarification in vm-beyondphys-policy
02/13/15 (Glen Granzow @ College of Idaho): typo in cpu-mechanisms
02/09/15 (Perry Kivolowitz): some clarity suggested and hopefully provided in vm-paging
02/06/15 (Joe Jean @ NYU): clarifications around homework in cpu-intro
01/05/14: Added new traces in cpu-intro
01/04/14: Added new homework for cpu-intro
01/02/15 (Perry Kivolowitz): strong philosophical disagreement in vm-api which we eventually agreed with
01/31/15 (Michael Walfish @ NYU): typo in cpu-api
01/30/15 (David Hartman): typo in cpu-intro
01/28/15 (Dheeraj Shetty @ NC State): typo in vm-paging
01/26/15 (Emad Sadeghi): typo in intro
01/21/15 (Ali Razeen @ Duke): typo in vm-beyondphys-policy
01/11/15 (Huseyin Sular): typo in intro
01/11/15 (Brian Gorman): clarification in threads-api
01/03/15 (Authors): typos in file-integrity, file-raid, file-journaling, vm-paging, vm-tlbs
01/03/15 (Hao Chen): typo in file-raid
12/30/14 (Adriana Iamnitchi and class @ USF): typos and other fixes in cpu-mechanisms, vm-freespace, threads-sema, file-implementation, file-ffs
12/30/14 (Hao Chen): typo in file-raid
12/29/14 (Erik Turk): typo in vm-vax
12/17/14 (Riccardo Mutschlechner): typos in file-lfs
12/17/14 (William Royle @ Grinnell): clarified number of I/Os in simple write in file-implementation
12/14/14 (Yudong Sun): missing cite in dist-intro
12/10/14 (Hao Chen): typo in vm-paging figure 18.7
12/08/14 (Rohan Das @ Toronto): typos in vm-mechanism, vm-segmentation, vm-paging, vm-tlbs, threads-intro, threads-sema, file-intro
12/02/14 (John Brady @ Grinnell): typo in file-lfs
11/24/14 (Itai Hass @ Toronto): typo in file-implementation
11/24/14 (Jerod Weinman @ Grinnell): typo in file-implementation
11/17/14 (Nick Weinandt): typo in file-journaling
11/11/14 (Yudong Sun): typo in threads-sema
11/06/14 (Itai Hass @ Toronto): typo in vm-mechanism
10/29/14 (Andrew Valencik @ Saint Mary's): typos in threads-intro homework
10/27/14 (Eduardo Stelmaszczyk): bug in threads-bugs
10/16/14 (Rohan Das @ Toronto): typo in cpu-sched
10/13/14 (Jerod Weinman @ Grinnell): clearer prose in threads-bugs
10/13/14 (Joel Kuntz @ Saint Mary's): typo in vm-paging
09/15/14 (Robert Ordonez @ Southern Adventist): typo in vm-vax
10/04/14 (Jerod Weinman @ Grinnell): better fig placement in threads-locks
09/23/14 (Aditya Venkataraman): typo in threads-api
09/17/14 (Jiao Dong @ Rutgers): correct attribution of Confucius quote.
09/15/14 (Robert Ordonez @ Southern Adventist): typo in vm-smalltables
09/15/14 (Robert Ordonez and class @ Southern Adventist): suggestions for improvement for cpu-sched
09/12/14 (Liang Yin): typo in vm-segmentation
09/08/14 (Caleb Sumner @ Southern Adventist U.): typo in cpu-api homework
09/04/14: Added new homework for threads-locks
09/03/14 (Rohan Pasalkar @ Minnesota): typos in file-lfs , file-integrity , dist-nfs
08/26/14 (Riccardo Mutschlechner): typos in file-implementation
08/05/14 (Riccardo Mutschlechner): typos in file-intro, file-devices, file-disks, file-raid
08/01/14 (Riccardo Mutschlechner): typo in threads-cv
07/28/14 (Christoph Jaeger @ HTWK Leipzig): bug in diagram in vm-mechanism
07/28/14: Added new homework for cpu-api
07/26/14: Added new homework for vm-freespace
07/02/14 (Jan Reineke @ Saarland): graph bug in cpu-sched-mlfq
07/02/14 (Kartik Singhal): typo in cpu-intro citations
06/30/14 (Hugo Diaz): typo in intro code snippet
06/10/14 (Adam Drescher @ WUSTL): many suggestions and fixed in vm-paging, vm-segmentation, vm-tlbs, cpu-mechanisms, cpu-intro, cpu-sched-lottery, file-ffs, vm-smalltables, vm-intro, vm-freespace, vm-mechanism, cpu-sched-multi, cpu-sched-mlfq
06/08/14 (Akiel Khan): typo in threads-intro
05/29/14 (Riccardo Mutschlechner): typo in vm-paging
v0.80 05/26/14: v0.80 RELEASED: includes many small fixes and lower price hard and soft covers
05/22/14 (Neeraj Badlani @ NC State): table typos in threads-cv
05/22/14 (Mohammed Alali @ Delaware): typo in vm-freespace
05/19/14 (Adam Drescher @ WUSTL): typo in cpu-sched
05/18/14 (Mohammed Alali @ Delaware): typo in vm-intro
05/18/14 (Adam Drescher @ WUSTL): typo in cpu-sched
05/15/14 (Chien-Chung Shen @ Delaware): typo in file-implementation
05/13/14 (Chien-Chung Shen @ Delaware): typo in file-intro
05/03/14 (Samer Al-Kiswany): corrections in file-intro , file-implementation , file-journaling , file-lfs , file-integrity
05/02/14 (Dorian Arnold @ New Mexico): bug in disk.py homework tool
05/01/14 (Chien-Chung Shen @ Delaware): consistency problem in vm-tlbs
04/29/14 (Satish Chebrolu @ NetApp): typo in cpu-mechanism
04/28/14 (Chien-Chung Shen @ Delaware): consistency problem in vm-freespace
04/25/14 (Chien-Chung Shen @ Delaware): typo in vm-paging
04/16/14 (Leslie Schultz): typo in file-devices
04/13/14 (Patricio Jara): bug in Zemaphore code in threads-sema
04/07/14 (Mohammed Alali @ Delaware): typo in threads-locks
03/31/14 (Chien-Chung Shen @ Delaware): bad cite in vm-api
03/22/14 (Chien-Chung Shen @ Delaware): two sema value mistakes in threads-sema
03/14/14 (Shreevatsa R.): typos in intro and vm-smalltables
03/14/14: Added new homework for threads-intro ; download it and play around to learn more about race conditions and related fun!
03/04/14: Updates to everything in the Appendix - redid table to have more verbose chapter titles - some other small fixes
03/12/14 (Jonathan Perry @ MIT): figure incorrect in file-disk
03/04/14: New homework in dist-afs to simulate AFS cache consistency
02/28/14 (Brian Kroth): typo in vm-beyondphys-policy
02/23/14 (Ming Chen @ Stonybrook): missing cite in file-journaling
v0.70 02/16/14: v0.70 RELEASED: Major updates throughout to Version 0.7. This can be considered a final version of the text and figures; only homeworks and bug fixes for various chapters will be added to get to version 1.0. Changes include: re-format of entire book to fit more text onto each page (saves a few bucks in the printed version, and looks a little better); added proper copyright notice and link to www.ostep.org on page footers; a few more people to thank in the acks; added list of tables; added line numbers to most code snippets added figure to cpu-intro , plus a little more description; added another example to cpu-api , plus aside; small rewrites to cpu-sched ; new pics to cpu-sched-multi ; new pic in vm-freespace ; decent rewrite of vm-tlbs including better example, aside, and pics; added some text to vm-beyondphys to clarify terms; additional policy discussion in vm-beyondphys-policy ; some detailed traces in threads-cv plus clarifying text; some detailed traces in threads-sema , plus clarification of Semaphore definition as per original paper; discussion of signals in threads-events ; better pics in file-devices ; nice piece on dimensional analysis in file-disks ; new graph of amortization in file-ffs ; many new figures in file-journaling , as well as new text and timelines of journal protocols; new pics in file-integrity ; new traces in dist-afs , as well as timelines, an aside, and an analysis of NFS/AFS; bug fixes throughout; new citations throughout
02/06/14 (Jun He): typos in file-intro and vm-mechanism
01/20/14 (Bjorn Lindberg): clarified random number generation in cpu-sched-lottery
01/19/14 (Thomas Griebel): added cover art
01/19/14 (Matty Williams): suggestion for hyperlinks, etc. in e-version
01/19/14 (Nelson Gomez): typo in intro
01/19/14 (Bobby Jack): typos in intro
01/19/14: Added some cover art - a picture of Halley's comet (hat tip to Thomas Griebel). Plus lots of other fixes, thanks to those at Hacker News and elsewhere
01/18/14 (Varun Vats): typo in preface
01/06/14 (Biswajit Mazumder @ Clemson): Clarification in vm-segmentation
01/06/14 (Nghia Huynh @ Texas): Incorrect type in lowlevellock in threads-locks
12/20/13 (Ernst Biersack @ France): typo in file-raid homework
12/17/13 (Emmett Witchel @ Texas): incorrect bit about NFS permissions dist-nfs
12/05/13 (Satyanarayana Shanmugam): typo in file-lfs picture
12/03/13 (Ruslan Kiselev): small fixes in file-disk and file-raid
11/22/13 (Satyanarayana Shanmugam): typos in file-integrity
11/14/13 (Satyanarayana Shanmugam): typo in RAID homework file-raid
11/05/13: Some updates to File Intro - basically more details on fsync(), rename(), and how to use them for atomic update
10/18/13 (Huanchen Zhang): typo in dist-nfs
10/14/13 (Satyanarayana Shanmugam): clarified OOM in vm-beyondphys-policy
10/11/13 (Masashi Kishikawa): fixed two bugs in threads-sema
10/11/13 (Satyanarayana Shanmugam): small bug in threads-cv
09/20/13 (Masashi Kishikawa): fixed bug in figure in vm-freespace
09/17/13 (Tongxin Zheng): wrong modes in cpu-mechanism
09/06/13: Some updates to Limited Direct Execution chapter - small bug fix in Semaphores
08/19/13 (Anand Mundada): small typo in threads-sema
08/15/13: Moved all of the homework simulator information OUT of the end of chapters and into README files, which can be downloaded from the homework page. All that is left at the end of chapters with simulators are the questions you might want to answer by using the simulator
v0.60 08/14/13: v0.60 RELEASED: Too much to list here; basically, went through the entire book and replaced text figures with actual drawn figures; made sure each chapter had at least one crux (problem); made sure that there were tips and asides throughout; reduced all previous sidebar material to just tips and asides; added citations in a few spots; added some new data here and there. All of this is now called version 0.6 which is getting close to a finished product (modulo a few homeworks). The rough list of chapters that have been updated includes: intro (new asides), cpu-api (aside, citations), cpu-sched (crux), cpu-sched-lottery (new data, homework changes, new tip, crux), cpu-sched-mlfq (redid pictures entirely), cpu-sched-multi (added chapter itself, graphical pics), vm-api (fixed reference), vm-mechanism (resized figures for readability), vm-freespace (redid pictures), vm-paging (added crux, rewrote here and there, added summary at end of chapter), vm-smalltables (added crux, some rewrites here and there, added a cite), threads-intro (fixed references), threads-sema (added crux), threads-locks-usage (added new chapter, fixed bugs), threads-events (added chapter itself), file-intro (fixed reference), file-raid (added crux, rewrote bits and pieces, added a few citations), file-implementation (redid pictures entireyly), file-ffs (new data, added pictures), file-lfs (redid pictures entirely), file-integrity (added chapter itself), dist-intro (added pics)
08/12/13 (Torin Rudeen @ Princeton): many fixed in threads-locks-usage
08/03/13 (Charlotte Kissinger): typos in file-devices and dialogue-persistence and file-raid
08/02/13: Added final distributed summary dialogue
08/02/13: Added a rough version on concurrent data structures with locks
08/02/13: Added a rough version of a new chapter on event-based concurrency (finally!)
08/02/13: Thinking about doing these long entries in a more verbose format
07/31/13 (Deepika Muthukumar): wrong XOR calculation in file-integrity
07/26/13 (Yue Zhuo): missing shift in vm-smalltables ; also encouragement to update the darn website, leading to a slew of updates
07/26/13: Added new summary dialogue for file systems
07/26/13: Added new hardcover edition
07/26/13: Revised softcover edition
07/26/13: Revised electronic full PDF
07/26/13: New chapter on Multiprocessor Scheduling
07/26/13: New chapter on (replaces and generalizes deadlock chapter)
07/26/13: New chapter on Data Integrity (replaces pending file-modern)
07/26/13: Upcoming chapter on event-based concurrency is next
03/15/13 (Hrishikesh Amur): overclaim about windows device drivers
03/14/13 (Yufui Ren): graph typo in cpu-sched
02/26/13 (Ajaykrishna Raghavan): typo in cites in vm-freespace
02/21/13 (Nathan Dipiazza): typo in vm-beyondphys
02/17/13 (Zuyu Zhang): typo in cpu-mechanism
01/24/13 (Kaushik Kannan): footnote about AS randomization needed
01/21/13 (Lei Tian @ Nebraska-Lincoln): bug in disk.py homework tool
01/21/13 (Varun Vats): typo in threads-intro
01/12/13: Updates to vm-freespace, vm-segmentation
01/09/13: A number of fixes thanks to various bug reports: see errata
12/19/12 (B. Brahmananda Reddy): typo in cpu-mechanism
12/01/12 (Sandeep Ummadi): bugs in vmm-intro , dialogue-concurrency
10/20/12 (Joel Sommers @ Colgate): -pthread not -lpthread on link line in intro, threads-api, threads-intro
10/18/12 (Xu Di): permissions detail in file-implementation , bug in disk simulator
10/14/12 (Joel Sommers @ Colgate): missing destroy calls in threads-api
10/01/12 (Jerod Weinman @ Grinnell): typos in vm-freespace , file-disks , file-journaling
09/01/12 (David Hanle): typo in vm-segmentation
08/20/12 (Bala Subrahmanyam Kambala): typo in dialogue-virtualization
07/19/12: Moved to one less easy piece!
06/20/12 (Benita Bose): typos in file-ffs, dist-intro, file-journaling, file-implementation
06/15/12: Finally caught up on many many student fixes and such
05/19/12 (Suriyhaprakhas Balaram Sankari): typos in file-devices , file-disks
05/17/12 (Sharad Punuganti): typos in dist-nfs , file-intro , threads-intro , dist-intro
05/14/12 (Adam Eggum): disk simulator crash
05/12/12 (Guilherme Baptista): typos in threads-sema
04/24/12 (Finn Kuusisto): Many typos in cpu-api , cpu-mechanism , cpu-sched , vm-segmentation , vm-freespace (actually used the word <“>suck<”> by accident!), vm-smalltables , vm-beyondphys-policy , threads-cv , file-journaling
04/24/12 (Sivaraman Sivaraman): mistake in math term in file-disks
04/12/12 (James Perry @ UM-D): many typos in file-journaling, file-implementation, file-ffs
04/08/12: Updated file-journaling somewhat substantially
04/03/12 (Jake Gillberg): wrong variable in threads-cv
03/22/12 (Emily Jacobson): RAID terminology fix in file-raid
03/20/12: More pictures in file-devices ; a little more text too
03/12/12 (Sivaraman Sivaraman): two typos in threads-api and one small but critical fix in vm-segmentation example calculation.
03/12/12 (Benita Bose): typo in vm-dialogue , and a few problems in threads-intro
03/10/12 (Sivaraman Sivaraman): cache sizes of N, N+1 mixed up in vm-beyondphys-policy
03/05/12 (Sivaraman Sivaraman): typo in vm-mechanism , which I kept claiming wasn't there! (but it was)
03/05/12 (Shreevatsa R.): many fixes in threads-lock , threads-cv
03/05/12 (Tony Adkins): typo in dialogue-concurrency
03/01/12 (Benita Bose): typo in vm-mechanism
03/01/12 (Shreevatsa R.): typos in threads-init and threads-api
02/14/12 (James Perry @ UM-D): typo in cpu-sched-lottery ; typo in cpu-api, vm-tlbs, vm-intro, threads-api, file-implementation
02/14/12 (Ripudaman Singh): small code bug in threads-deadlock
02/11/12 (Charlotte Kissinger): Figures in cpu-sched are incorrectly labeled
02/10/12: Update of NFS chapter
02/10/12: Update of TLB code example
02/09/12 (Tony Adkins): Code example in vm-tlbs is unclear
02/04/12 (Xiang Peng): unrestricted in vm-mechanism should be restricted (or privileged)
01/12/12: Minor fixes to many many chapters thanks to many students
12/06/11: New Distributed Systems intro
12/06/11: New Distributed Systems dialogue
11/03/11: A number of fixes to devices and all early file system chapters
10/11/11: Re-org of concurrency chapters
Fall'12 (Srinivasan Thirunarayanan): Fixes to file-implementation, file-journaling, file-lfs, dist-afs, file-devices, threads-sema, vm-intro, file-implementation homework, file-disks, vm-beyondphys-policy, vm-beyondphys, vm-smalltables, vm-paging, vm-paging homework, vm-relocation, cpu-api
Fall'12 (Abhirami Senthilkumaran): Fixes to file-intro, file-implementation, file-journaling, file-lfs, file-disk, vmm-intro, vm-beyondphys-policy, cpu-sched-lottery, intro, vm-smalltables
Fall'12 (Huanchen Zhang): Fixes to file-raid, file-implementation, file-journaling, vm-mechanism, vm-tlbs, vm-smalltables, threads-locks, cpu-sched
Fall'12 (Henry Abbey): Fixes to threads-deadlock, file-devices, file-implementation, dist-nfs, vm-tlbs
Fall'12 (Sy Jin Cheah): Fixes to intro, file implementation, file-ffs, file-lfs, dist-afs, threads-cv
Fall'12 (Cara Lauritzen): Fixes to threads-deadlock, file-devices
Fall'12 (Brennan Payne): Suggestion for more/better summaries, fixes to vm-segmentation
Fall'12 (Ripudaman Singh): Fixes to vm-paging, vm-beyondphys-policy , homeworks for both
Fall'12 (Nathan Sullivan): Fixes to intro, cpu-sched-lottery, vm-paging, vm-beyondphys, vm-beyondphys-policy, lab-tutorial
Fall'12 (Lihao Wang): Fixes to vm-tlbs, vm-relocation
Fall'12 (Balasubramanian): Fixes to cpu-api, cpu-mechanisms
Fall'12 (Meng Huang): Fixes to file-implementation, threads-cv
Fall'12 (Ross Aiken): Files to file-journaling
Fall'12 (Seth Pollen): Fixes to file-journaling
09/20/11 (Huanchen Zhang): Process intro: extra will
09/20/11 (Srinivasan Thirunarayanan): Process API: typo in code snippet.
09/20/11 (Brennan Payne): Segmentation: typo in we get a physical address of 39016, which is not get the correct physical address.
09/06/11 (Martha Ferris): Intro: to difficult s.b. to be difficult ... Intro: not to have write in assembly s.b. not to have to write in assembly
07/30/11 (Karl Wallinger): Scheduling: ...of course there a number of different... missing an are
07/25/11: Added new chapter on thread API
07/25/11: Small update to thread intro
07/05/11: Added new dialogue
06/29/11: Added new simulator (lottery.py) and homework into this chapter
06/29/11: Update of lottery scheduling
06/26/11: Updated table of contents
06/24/11: Added new simulator (paging-policy.py) and homework here
06/24/11: Added new homework to this chapter
06/24/11: Added new homework to this chapter
06/23/11: Added new simulator (relocation.py) into this chapter
06/23/11: Updated intro to address translation
06/13/11: Slight update to intro chapter.
06/14/11 (Karl Wallinger): Intro: extra would
06/08/11 (Mike Griepentrog): Lab: Expert C Programming is still in print
06/08/11: Added new disk simulator (disk.py) and homework here.
06/03/11: Added new RAID simulator (raid.py) and homework here.
06/03/11: Started this page to track book updates
05/20/11 (Ahmed Fikri): About 30 different comments, too many to list here
05/14/11 (Dustin Metzler): Chapter numbering confusing
05/11/11 (Radford Smith): FFS: to allocate the data blocks of an file ... LFS: and hence to overall name of the log-structured file system ... LFS: (where NxM) .. LFS: On top the mechanism described above
05/10/11 (Dustin Passofaro): AFS: state file should be stale file ... NFS if case should be in case ... RAID: other interesting that should be other interesting ideas that ... Intro: it simple -> it simply ... Deadlock: more more should be more ... Locks: it simple calls s.b. it simply calls ... Devices: for the OS send s.b. for the OS to send
05/10/11 (Alex Wyler): file-journaling now and not not in we are not/now also writing to the journal first
05/06/11 (Kevin Liu): cpu-api complete mispelled as comlplete
04/27/11 (Radford Smith): threads-locks-hw forgot lock_t at end of typedef.
04/25/11 (Murugan Kandaswamy): dist-nfs ... server (not client ) does not reply in a timely manner?
03/11/11 (Ryland Herrick): threads-sema Lookups , not inserts .
03/11/11 (Ryland Herrick): threads-locks-hw Missing ! in LL/SC lock.
03/02/11 (Alex Wyler): paging-smalltables Bits PFN7 and PT7 don't exist.
03/02/11 (Jay Lim): vmm-intro discuss not discus .
03/02/11 (Zef RosnBrick): vm-segmentation fixed is not get the correct physical address by removing get
03/02/11 (Zef RosnBrick): cpu-sched-mlfq replaced of with than
02/23/11 (Dan Soendergaard @ U. Aarhus): dialogue-virtualization illusion misspelled as illision
05/10/10 (Tuo Wang): vm-relocation 32KB is 32768
05/10/10 (Tuo Wang): vm-relocation fetch from correct addresses
05/10/10 (Tuo Wang): vm-paging number of numerical typos
05/10/10 (Tuo Wang): vm-smalltables 55 not 45
05/10/10 (Tuo Wang): file-lfs unclear sentence about buffering
05/08/10 (Matt Reichoff): file-raid design should be designed
03/05/10 (Cody Hanson): vm-relocation you can how should be you can see how
01/24/10 (Natasha Eilbert): lab-tutorial p.1 you said Unlike Java, there is no connection between the file name and the contents of the file; because of that, just use your common sense in naming files. After thinking about this for a little bit I got what you meant, but at first was confused and thought you were saying that in C there actually _shouldn't_ be any relation at all between the filename and its contents! Maybe you could say something like no enforced connection .
01/24/10 (Natasha Eilbert): lab-tutorial p. 4 that that should just be that
01/24/10 (Natasha Eilbert): lab-tutorial p. 8 defintion should be definition
10/24/09 (Kevin Liu): m2 - Sample assembly code on page two shows address 128, 130 and 134. However, the addresses in the diagram on page 3 shows addresses 128, 130, 133.
10/24/09 (Kevin Liu): m3 page 5: next 11 bits should be next 12 bits
10/24/09 (Kevin Liu): m3 page 5: In the C pseucode-code section, && should be replaced by &.
10/24/09 (Kevin Liu): m3 page 8: Perhaps mention that the free list management policy does not get rid of external fragmentation, but simply tries to minimize it.
10/24/09 (Kevin Liu): m4 page 4: The example showing the translation from virtual address 21 seems to have a mistake. We picked PFN 5, however, going by Figure 12.2, we should have picked PFN 7. This would mean that our physical address should be 117 instead of 85.
10/24/09 (Kevin Liu): m5 page 2: CISC is defined as complex-instruction set computing , however, RISC is defined as reduced-instruction set computers . Should change one of the two to make the definitions consistent.
10/24/09 (Kevin Liu): m6 page 3: Specifically, we use a tiny 16KB address space with 1KB pages (Figure 14.2) . Should be Figure 14.1.
10/24/09 (Kevin Liu): m6 page 8: At PhysAddr1 (some physical address, or, if the page directory is page-aligned, just the physical frame number), we have the first chunk of 16 page table entries for the first 16 VPNs in the address space. It would look something like what you see in Figure 14.2. Should be Figure 14.3. Also, the text refers to the diagrams as Figures but they are actually labeled as Tables .
10/24/09 (Kevin Liu): m6 page 10: page 254 of VA space is mapped to PFN 55, not 45.
10/24/09 (Kevin Liu): m8 page 10: However, in many cases the importance of said algorithms has decreased, as the discrepancy between memory-access and disk-access times has increased. Should be decreased, not increased.