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| * | | | | | rcu classic: new algorithm for callbacks-processing(v2)Lai Jiangshan2008-07-182-69/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is v2, it's a little deference from v1 that I had send to lkml. use ACCESS_ONCE use rcu_batch_after/rcu_batch_before for batch # comparison. rcutorture test result: (hotplugs: do cpu-online/offline once per second) No CONFIG_NO_HZ: OK, 12hours No CONFIG_NO_HZ, hotplugs: OK, 12hours CONFIG_NO_HZ=y: OK, 24hours CONFIG_NO_HZ=y, hotplugs: Failed. (Failed also without my patch applied, exactly the same bug occurred, http://lkml.org/lkml/2008/7/3/24) v1's email thread: http://lkml.org/lkml/2008/6/2/539 v1's description: The code/algorithm of the implement of current callbacks-processing is very efficient and technical. But when I studied it and I found a disadvantage: In multi-CPU systems, when a new RCU callback is being queued(call_rcu[_bh]), this callback will be invoked after the grace period for the batch with batch number = rcp->cur+2 has completed very very likely in current implement. Actually, this callback can be invoked after the grace period for the batch with batch number = rcp->cur+1 has completed. The delay of invocation means that latency of synchronize_rcu() is extended. But more important thing is that the callbacks usually free memory, and these works are delayed too! it's necessary for reclaimer to free memory as soon as possible when left memory is few. A very simple way can solve this problem: a field(struct rcu_head::batch) is added to record the batch number for the RCU callback. And when a new RCU callback is being queued, we determine the batch number for this callback(head->batch = rcp->cur+1) and we move this callback to rdp->donelist if we find that head->batch <= rcp->completed when we process callbacks. This simple way reduces the wait time for invocation a lot. (about 2.5Grace Period -> 1.5Grace Period in average in multi-CPU systems) This is my algorithm. But I do not add any field for struct rcu_head in my implement. We just need to memorize the last 2 batches and their batch number, because these 2 batches include all entries that for whom the grace period hasn't completed. So we use a special linked-list rather than add a field. Please see the comment of struct rcu_data. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | rcu classic: simplify the next pending batchLai Jiangshan2008-07-182-15/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | use a batch number(rcp->pending) instead of a flag(rcp->next_pending) rcu_start_batch() need to change this flag, so mb()s is needed for memory-access safe. but(after this patch applied) rcu_start_batch() do not change this batch number(rcp->pending), rcp->pending is managed by __rcu_process_callbacks only, and troublesome mb()s are eliminated. And codes look simpler and clearer. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Gautham Shenoy <ego@in.ibm.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2008-10-1036-141/+995
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: selinux: Fix an uninitialized variable BUG/panic in selinux_secattr_to_sid() selinux: use default proc sid on symlinks file capabilities: uninline cap_safe_nice Update selinux info in MAINTAINERS and Kconfig help text SELinux: add gitignore file for mdp script SELinux: add boundary support and thread context assignment securityfs: do not depend on CONFIG_SECURITY selinux: add support for installing a dummy policy (v2) security: add/fix security kernel-doc selinux: Unify for- and while-loop style selinux: conditional expression type validation was off-by-one smack: limit privilege by label SELinux: Fix a potentially uninitialised variable in SELinux hooks SELinux: trivial, remove unneeded local variable SELinux: Trivial minor fixes that change C null character style make selinux_write_opts() static
| * \ \ \ \ \ \ Merge branch 'next' into for-linusJames Morris2008-10-1036-141/+995
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| | * | | | | | selinux: Fix an uninitialized variable BUG/panic in selinux_secattr_to_sid()Paul Moore2008-10-041-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At some point during the 2.6.27 development cycle two new fields were added to the SELinux context structure, a string pointer and a length field. The code in selinux_secattr_to_sid() was not modified and as a result these two fields were left uninitialized which could result in erratic behavior, including kernel panics, when NetLabel is used. This patch fixes the problem by fully initializing the context in selinux_secattr_to_sid() before use and reducing the level of direct context manipulation done to help prevent future problems. Please apply this to the 2.6.27-rcX release stream. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | selinux: use default proc sid on symlinksStephen Smalley2008-09-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As we are not concerned with fine-grained control over reading of symlinks in proc, always use the default proc SID for all proc symlinks. This should help avoid permission issues upon changes to the proc tree as in the /proc/net -> /proc/self/net example. This does not alter labeling of symlinks within /proc/pid directories. ls -Zd /proc/net output before and after the patch should show the difference. Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | file capabilities: uninline cap_safe_niceSerge E. Hallyn2008-09-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reduces the kernel size by 289 bytes. Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Acked-by: Andrew G. Morgan <morgan@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | Merge branch 'master' into nextJames Morris2008-09-21893-7033/+26762
| | |\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: MAINTAINERS Thanks for breaking my tree :-) Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | Update selinux info in MAINTAINERS and Kconfig help textStephen Smalley2008-09-122-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the SELinux entry in MAINTAINERS and drop the obsolete information from the selinux Kconfig help text. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | SELinux: add gitignore file for mdp scriptJames Morris2008-09-051-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add gitignore file for scripts/selinux/mdp/mdp. Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | SELinux: add boundary support and thread context assignmentKaiGai Kohei2008-08-297-20/+398
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The purpose of this patch is to assign per-thread security context under a constraint. It enables multi-threaded server application to kick a request handler with its fair security context, and helps some of userspace object managers to handle user's request. When we assign a per-thread security context, it must not have wider permissions than the original one. Because a multi-threaded process shares a single local memory, an arbitary per-thread security context also means another thread can easily refer violated information. The constraint on a per-thread security context requires a new domain has to be equal or weaker than its original one, when it tries to assign a per-thread security context. Bounds relationship between two types is a way to ensure a domain can never have wider permission than its bounds. We can define it in two explicit or implicit ways. The first way is using new TYPEBOUNDS statement. It enables to define a boundary of types explicitly. The other one expand the concept of existing named based hierarchy. If we defines a type with "." separated name like "httpd_t.php", toolchain implicitly set its bounds on "httpd_t". This feature requires a new policy version. The 24th version (POLICYDB_VERSION_BOUNDARY) enables to ship them into kernel space, and the following patch enables to handle it. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | securityfs: do not depend on CONFIG_SECURITYEric Paris2008-08-284-25/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new Kconfig option SECURITYFS which will build securityfs support but does not require CONFIG_SECURITY. The only current user of securityfs does not depend on CONFIG_SECURITY and there is no reason the full LSM needs to be built to build this fs. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | Merge branch 'master' into nextJames Morris2008-08-285189-115513/+177973
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| | * | | | | | | | selinux: add support for installing a dummy policy (v2)Serge E. Hallyn2008-08-278-1/+355
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In August 2006 I posted a patch generating a minimal SELinux policy. This week, David P. Quigley posted an updated version of that as a patch against the kernel. It also had nice logic for auto-installing the policy. Following is David's original patch intro (preserved especially bc it has stats on the generated policies): se interested in the changes there were only two significant changes. The first is that the iteration through the list of classes used NULL as a sentinel value. The problem with this is that the class_to_string array actually has NULL entries in its table as place holders for the user space object classes. The second change was that it would seem at some point the initial sids table was NULL terminated. This is no longer the case so that iteration has to be done on array length instead of looking for NULL. Some statistics on the policy that it generates: The policy consists of 523 lines which contain no blank lines. Of those 523 lines 453 of them are class, permission, and initial sid definitions. These lines are usually little to no concern to the policy developer since they will not be adding object classes or permissions. Of the remaining 70 lines there is one type, one role, and one user statement. The remaining lines are broken into three portions. The first group are TE allow rules which make up 29 of the remaining lines, the second is assignment of labels to the initial sids which consist of 27 lines, and file system labeling statements which are the remaining 11. In addition to the policy.conf generated there is a single file_contexts file containing two lines which labels the entire system with base_t. This policy generates a policy.23 binary that is 7920 bytes. (then a few versions later...): The new policy is 587 lines (stripped of blank lines) with 476 of those lines being the boilerplate that I mentioned last time. The remaining 111 lines have the 3 lines for type, user, and role, 70 lines for the allow rules (one for each object class including user space object classes), 27 lines to assign types to the initial sids, and 11 lines for file system labeling. The policy binary is 9194 bytes. Changelog: Aug 26: Added Documentation/SELinux.txt Aug 26: Incorporated a set of comments by Stephen Smalley: 1. auto-setup SELINUXTYPE=dummy 2. don't auto-install if selinux is enabled with non-dummy policy 3. don't re-compute policy version 4. /sbin/setfiles not /usr/sbin/setfiles Aug 22: As per JMorris comments, made sure make distclean cleans up the mdp directory. Removed a check for file_contexts which is now created in the same file as the check, making it superfluous. Signed-off-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: David Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | security: add/fix security kernel-docRandy Dunlap2008-08-203-21/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add security/inode.c functions to the kernel-api docbook. Use '%' on constants in kernel-doc notation. Fix several typos/spellos in security function descriptions. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | selinux: Unify for- and while-loop styleVesa-Matti Kari2008-08-156-24/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace "thing != NULL" comparisons with just "thing" to make the code look more uniform (mixed styles were used even in the same source file). Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | selinux: conditional expression type validation was off-by-oneVesa-Matti Kari2008-08-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | expr_isvalid() in conditional.c was off-by-one and allowed invalid expression type COND_LAST. However, it is this header file that needs to be fixed. That way the if-statement's disjunction's second component reads more naturally, "if expr type is greater than the last allowed value" ( rather than using ">=" in conditional.c): if (expr->expr_type <= 0 || expr->expr_type > COND_LAST) Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | smack: limit privilege by labelCasey Schaufler2008-08-053-1/+102
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been a number of requests to make the Smack LSM enforce MAC even in the face of privilege, either capability based or superuser based. This is not universally desired, however, so it seems desirable to make it optional. Further, at least one legacy OS implemented a scheme whereby only processes running with one particular label could be exempt from MAC. This patch supports these three cases. If /smack/onlycap is empty (unset or null-string) privilege is enforced in the normal way. If /smack/onlycap contains a label only processes running with that label may be MAC exempt. If the label in /smack/onlycap is the star label ("*") the semantics of the star label combine with the privilege restrictions to prevent any violations of MAC, even in the presence of privilege. Again, this will be independent of the privilege scheme. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: James Morris <jmorris@namei.org>
| | * | | | | | | | SELinux: Fix a potentially uninitialised variable in SELinux hooksDavid Howells2008-08-051-18/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a potentially uninitialised variable in SELinux hooks that's given a pointer to the network address by selinux_parse_skb() passing a pointer back through its argument list. By restructuring selinux_parse_skb(), the compiler can see that the error case need not set it as the caller will return immediately. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | SELinux: trivial, remove unneeded local variableVesa-Matti J Kari2008-08-051-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hello, Remove unneeded local variable: struct avtab_node *newnode Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | SELinux: Trivial minor fixes that change C null character styleVesa-Matti J Kari2008-08-053-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trivial minor fixes that change C null character style. Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Signed-off-by: James Morris <jmorris@namei.org>
| | * | | | | | | | make selinux_write_opts() staticAdrian Bunk2008-08-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes the needlessly global selinux_write_opts() static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: James Morris <jmorris@namei.org>
* | | | | | | | | | Merge branch 'sched-v28-for-linus' of ↵Linus Torvalds2008-10-1029-487/+702
|\ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (38 commits) sched debug: add name to sched_domain sysctl entries sched: sync wakeups vs avg_overlap sched: remove redundant code in cpu_cgroup_create() sched_rt.c: resch needed in rt_rq_enqueue() for the root rt_rq cpusets: scan_for_empty_cpusets(), cpuset doesn't seem to be so const sched: minor optimizations in wake_affine and select_task_rq_fair sched: maintain only task entities in cfs_rq->tasks list sched: fixup buddy selection sched: more sanity checks on the bandwidth settings sched: add some comments to the bandwidth code sched: fixlet for group load balance sched: rework wakeup preemption CFS scheduler: documentation about scheduling policies sched: clarify ifdef tangle sched: fix list traversal to use _rcu variant sched: turn off WAKEUP_OVERLAP sched: wakeup preempt when small overlap kernel/cpu.c: create a CPU_STARTING cpu_chain notifier kernel/cpu.c: Move the CPU_DYING notifiers sched: fix __load_balance_iterator() for cfq with only one task ...
| * | | | | | | | | | sched debug: add name to sched_domain sysctl entriesIngo Molnar2008-10-092-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | add /proc/sys/kernel/sched_domain/cpu0/domain0/name, to make it easier to see which specific scheduler domain remained at that entry. Since we process the scheduler domain tree and simplify it, it's not always immediately clear during debugging which domain came from where. depends on CONFIG_SCHED_DEBUG=y. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | | | | | | sched: sync wakeups vs avg_overlapPeter Zijlstra2008-10-081-8/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While looking at the code I wondered why we always do: sync && avg_overlap < migration_cost Which is a bit odd, since the overlap test was meant to detect sync wakeups so using it to specialize sync wakeups doesn't make much sense. Hence change the code to do: sync || avg_overlap < migration_cost Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| *---. \ \ \ \ \ \ \ \ \ Merge branches 'sched/devel', 'sched/cpu-hotplug', 'sched/cpusets' and ↵Ingo Molnar2008-10-0829-480/+680
| |\ \ \ \ \ \ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'sched/urgent' into sched/core
| | | | * | | | | | | | | | cpusets: scan_for_empty_cpusets(), cpuset doesn't seem to be so constFrederic Weisbecker2008-10-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a warning on latest -tip: kernel/cpuset.c: Dans la fonction «scan_for_empty_cpusets» : kernel/cpuset.c:1932: attention : passing argument 1 of «list_add_tail» discards qualifiers from pointer target type Actually the struct cpuset *root passed in parameter to scan_for_empty_cpusets is not supposed to be const since an entry is added on the tail of its list. Just correct the qualifier. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | * | | | | | | | | | | kernel/cpu.c: create a CPU_STARTING cpu_chain notifierManfred Spraul2008-09-0817-1/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | sched: remove redundant code in cpu_cgroup_create()Li Zefan2008-10-061-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | css will be initialized by cgroup core. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | Merge branch 'linus' into sched/develIngo Molnar2008-10-06218-1429/+2430
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| | * | | | | | | | | | | | | sched_rt.c: resch needed in rt_rq_enqueue() for the root rt_rqDario Faggioli2008-10-041-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While working on the new version of the code for SCHED_SPORADIC I noticed something strange in the present throttling mechanism. More specifically in the throttling timer handler in sched_rt.c (do_sched_rt_period_timer()) and in rt_rq_enqueue(). The problem is that, when unthrottling a runqueue, rt_rq_enqueue() only asks for rescheduling if the runqueue has a sched_entity associated to it (i.e., rt_rq->rt_se != NULL). Now, if the runqueue is the root rq (which has a rt_se = NULL) rescheduling does not take place, and it is delayed to some undefined instant in the future. This imply some random bandwidth usage by the RT tasks under throttling. For instance, setting rt_runtime_us/rt_period_us = 950ms/1000ms an RT task will get less than 95%. In our tests we got something varying between 70% to 95%. Using smaller time values, e.g., 95ms/100ms, things are even worse, and I can see values also going down to 20-25%!! The tests we performed are simply running 'yes' as a SCHED_FIFO task, and checking the CPU usage with top, but we can investigate thoroughly if you think it is needed. Things go much better, for us, with the attached patch... Don't know if it is the best approach, but it solved the issue for us. Signed-off-by: Dario Faggioli <raistlin@linux.it> Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: minor optimizations in wake_affine and select_task_rq_fairAmit K. Arora2008-09-301-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch does following: o Removes unused variable and argument "rq". o Optimizes one of the "if" conditions in wake_affine() - i.e. if "balanced" is true, we need not do rest of the calculations in the condition. o If this cpu is same as the previous cpu (on which woken up task was running when it went to sleep), no need to call wake_affine at all. Signed-off-by: Amit K Arora <aarora@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: maintain only task entities in cfs_rq->tasks listBharata B Rao2008-09-251-17/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cfs_rq->tasks list is used by the load balancer to iterate over all the tasks. Currently it holds all the entities (both task and group entities) because of which there is a need to check for group entities explicitly during load balancing. This patch changes the cfs_rq->tasks list to hold only task entities. Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: fixup buddy selectionPeter Zijlstra2008-09-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should set the buddy even though we might already have the TIF_RESCHED flag set. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: more sanity checks on the bandwidth settingsPeter Zijlstra2008-09-231-5/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While playing around with it, I noticed we missed some sanity checks. Also add some comments while we're there. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: add some comments to the bandwidth codePeter Zijlstra2008-09-231-0/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hopefully clarify some of this code a little. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | sched: fixlet for group load balancePeter Zijlstra2008-09-231-13/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should not only correct the increment for the initial group, but should be consistent and do so for all the groups we encounter. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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| | *-. \ \ \ \ \ \ \ \ \ \ \ \ Merge branches 'sched/urgent' and 'sched/rt' into sched/develIngo Molnar2008-09-23178-1301/+1980
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| | | | * | | | | | | | | | | | | sched: compilation fix with gcc 3.4.6Krzysztof Helt2008-09-061-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I found that 2.6.27-rc5-mm1 does not compile with gcc 3.4.6. The error is: CC kernel/sched.o kernel/sched.c: In function `start_rt_bandwidth': kernel/sched.c:208: sorry, unimplemented: inlining failed in call to 'rt_bandwidth_enabled': function body not available kernel/sched.c:214: sorry, unimplemented: called from here make[1]: *** [kernel/sched.o] Error 1 make: *** [kernel] Error 2 It seems that the gcc 3.4.6 requires full inline definition before first usage. The patch below fixes the compilation problem. Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> (if needed> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: extract walk_tg_tree(), fixIngo Molnar2008-08-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fix: kernel/sched.c: In function '__rt_schedulable': kernel/sched.c:8771: error: implicit declaration of function 'walk_tg_tree' kernel/sched.c:8771: error: 'tg_nop' undeclared (first use in this function) kernel/sched.c:8771: error: (Each undeclared identifier is reported only once kernel/sched.c:8771: error: for each function it appears in.) Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: rt-bandwidth fixesPeter Zijlstra2008-08-191-62/+63
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The last patch allows sysctl_sched_rt_runtime to disable bandwidth accounting for the group scheduler - however it doesn't deal with sched_setscheduler(), which will keep tasks out of groups that have no assigned runtime. If we relax this, we get into the situation where RT tasks can get into a group when we disable bandwidth control, and then starve them by enabling it again. Rework the schedulability code to check for this condition and fail to turn on bandwidth control with -EBUSY when this situation is found. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: extract walk_tg_tree()Peter Zijlstra2008-08-191-33/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extract walk_tg_tree() and make it a little more generic so we can use it in the schedulablity test. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: rt-bandwidth group disable fixesPeter Zijlstra2008-08-192-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More extensive disable of bandwidth control. It allows sysctl_sched_rt_runtime to disable full group bandwidth control. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: rt-bandwidth accounting fixPeter Zijlstra2008-08-191-6/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It fixes an accounting bug where we would continue accumulating runtime even though the bandwidth control is disabled. This would lead to very long throttle periods once bandwidth control gets turned on again. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | | | * | | | | | | | | | | | | sched: rt-bandwidth for user grouping interfacePeter Zijlstra2008-08-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | rt_runtime is a signed value Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | sched: rework wakeup preemptionPeter Zijlstra2008-09-231-129/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rework the wakeup preemption to work on real runtime instead of the virtual runtime. This greatly simplifies the code. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | CFS scheduler: documentation about scheduling policiesMartin Steigerwald2008-09-231-2/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The documentation about the CFS scheduler is scarse when it comes to scheduling policies. This patch adds a chapter about the scheduling policies it supports. Peter Zijlstra provided most of the information for it in http://marc.info/?l=linux-kernel&m=122210038326356&w=2 Signed-off-by: Martin Steigerwald <ms@teamix.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | sched: clarify ifdef tangleAndrew Morton2008-09-231-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Add some comments to try to make the ifdef puzzle a bit clearer - Explicitly inline one of the three init_hrtick() implementations. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | sched: fix list traversal to use _rcu variantChris Friesen2008-09-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | load_balance_fair() calls rcu_read_lock() but then traverses the list using the regular list traversal routine. This patch converts the list traversal to use the _rcu version. Signed-off-by: Chris Friesen <cfriesen@nortel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| | * | | | | | | | | | | | | | | sched: turn off WAKEUP_OVERLAPIngo Molnar2008-09-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WAKEUP_OVERLAP is not a winner on a 16way box, running psql+sysbench: .27-rc7-NO_WAKEUP_OVERLAP .27-rc7-WAKEUP_OVERLAP ------------------------------------------------- 1: 694 811 +14.39% 2: 1454 1427 -1.86% 4: 3017 3070 +1.70% 8: 5694 5808 +1.96% 16: 10592 10612 +0.19% 32: 9693 9647 -0.48% 64: 8507 8262 -2.97% 128: 8402 7087 -18.55% 256: 8419 5124 -64.30% 512: 7990 3671 -117.62% ------------------------------------------------- SUM: 64466 55524 -16.11% ... so turn it off by default. Signed-off-by: Ingo Molnar <mingo@elte.hu>