From 3b524d60943a2f9ee1194323ff9d5ee01a4d1ce1 Mon Sep 17 00:00:00 2001 From: Li Bin Date: Mon, 9 Sep 2013 14:05:40 +0800 Subject: sched/Documentation: Update sched-design-CFS.txt documentation 2bd2d6f2dc ("sched: Replace use of entity_key()") had remove the entity_key() which function is to subtract a tasks vruntime by its groups minvruntime as the rbtree key. The phrase "there is a subtraction using rq->cfs.min_vruntime to account for possible wraparounds" in documentation feels strange and meaningless. So remove it. Signed-off-by: Li Bin Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1378706740-7500-1-git-send-email-huawei.libin@huawei.com Signed-off-by: Ingo Molnar --- Documentation/scheduler/sched-design-CFS.txt | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/scheduler/sched-design-CFS.txt b/Documentation/scheduler/sched-design-CFS.txt index d529e02d928d..f14f49304222 100644 --- a/Documentation/scheduler/sched-design-CFS.txt +++ b/Documentation/scheduler/sched-design-CFS.txt @@ -66,9 +66,7 @@ rq->cfs.load value, which is the sum of the weights of the tasks queued on the runqueue. CFS maintains a time-ordered rbtree, where all runnable tasks are sorted by the -p->se.vruntime key (there is a subtraction using rq->cfs.min_vruntime to -account for possible wraparounds). CFS picks the "leftmost" task from this -tree and sticks to it. +p->se.vruntime key. CFS picks the "leftmost" task from this tree and sticks to it. As the system progresses forwards, the executed tasks are put into the tree more and more to the right --- slowly but surely giving a chance for every task to become the "leftmost task" and thus get on the CPU within a deterministic -- cgit v1.2.3 From 7eacd03810960823393521063734fc8188446bca Mon Sep 17 00:00:00 2001 From: Neil Horman Date: Fri, 13 Sep 2013 11:05:33 -0400 Subject: bonding: Make alb learning packet interval configurable running bonding in ALB mode requires that learning packets be sent periodically, so that the switch knows where to send responding traffic. However, depending on switch configuration, there may not be any need to send traffic at the default rate of 3 packets per second, which represents little more than wasted data. Allow the ALB learning packet interval to be made configurable via sysfs Signed-off-by: Neil Horman Acked-by: Acked-by: Veaceslav Falico CC: Jay Vosburgh CC: Andy Gospodarek CC: "David S. Miller" Signed-off-by: Andy Gospodarek Signed-off-by: David S. Miller --- Documentation/networking/bonding.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation') diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 87bbcfee2e06..9b28e714831a 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -1362,6 +1362,12 @@ To add ARP targets: To remove an ARP target: # echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target +To configure the interval between learning packet transmits: +# echo 12 > /sys/class/net/bond0/bonding/lp_interval + NOTE: the lp_inteval is the number of seconds between instances where +the bonding driver sends learning packets to each slaves peer switch. The +default interval is 1 second. + Example Configuration --------------------- We begin with the same example that is shown in section 3.3, -- cgit v1.2.3 From 0854d450e229e37102a76e3ccf065d8e8137846f Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Mon, 16 Sep 2013 14:51:55 +0200 Subject: vfs: improve i_op->atomic_open() documentation Fix documentation of ->atomic_open() and related functions: finish_open() and finish_no_open(). Also add details that seem to be unclear and a source of bugs (some of which are fixed in the following series). Cc-ing maintainers of all filesystems implementing ->atomic_open(). Signed-off-by: Miklos Szeredi Cc: Eric Van Hensbergen Cc: Sage Weil Cc: Steve French Cc: Steven Whitehouse Cc: Trond Myklebust Signed-off-by: Al Viro --- Documentation/filesystems/vfs.txt | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'Documentation') diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index f93a88250a44..deb48b5fd883 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -359,11 +359,9 @@ struct inode_operations { ssize_t (*listxattr) (struct dentry *, char *, size_t); int (*removexattr) (struct dentry *, const char *); void (*update_time)(struct inode *, struct timespec *, int); - int (*atomic_open)(struct inode *, struct dentry *, + int (*atomic_open)(struct inode *, struct dentry *, struct file *, + unsigned open_flag, umode_t create_mode, int *opened); int (*tmpfile) (struct inode *, struct dentry *, umode_t); -} ____cacheline_aligned; - struct file *, unsigned open_flag, - umode_t create_mode, int *opened); }; Again, all methods are called without any locks being held, unless @@ -470,9 +468,11 @@ otherwise noted. method the filesystem can look up, possibly create and open the file in one atomic operation. If it cannot perform this (e.g. the file type turned out to be wrong) it may signal this by returning 1 instead of - usual 0 or -ve . This method is only called if the last - component is negative or needs lookup. Cached positive dentries are - still handled by f_op->open(). + usual 0 or -ve . This method is only called if the last component is + negative or needs lookup. Cached positive dentries are still handled by + f_op->open(). If the file was created, the FILE_CREATED flag should be + set in "opened". In case of O_EXCL the method must only succeed if the + file didn't exist and hence FILE_CREATED shall always be set on success. tmpfile: called in the end of O_TMPFILE open(). Optional, equivalent to atomically creating, opening and unlinking a file in given directory. -- cgit v1.2.3 From 374ed9d18e658704235b84a60589888ca52ab0fe Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 17 Sep 2013 11:46:23 +0100 Subject: arm64: documentation: tighten up tagged pointer documentation Commit d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") added support for tagged pointers in userspace, but the corresponding update to Documentation/ contained some imprecise statements. This patch fixes up some minor ambiguities in the text, hopefully making it more clear about exactly what the kernel expects from user virtual addresses. Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas --- Documentation/arm64/tagged-pointers.txt | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'Documentation') diff --git a/Documentation/arm64/tagged-pointers.txt b/Documentation/arm64/tagged-pointers.txt index 264e9841563a..d9995f1f51b3 100644 --- a/Documentation/arm64/tagged-pointers.txt +++ b/Documentation/arm64/tagged-pointers.txt @@ -18,17 +18,17 @@ this byte for application use, with the following caveats: parameters containing user virtual addresses *must* have their top byte cleared before trapping to the kernel. - (2) Tags are not guaranteed to be preserved when delivering - signals. This means that signal handlers in applications - making use of tags cannot rely on the tag information for - user virtual addresses being maintained for fields inside - siginfo_t. One exception to this rule is for signals raised - in response to debug exceptions, where the tag information + (2) Non-zero tags are not preserved when delivering signals. + This means that signal handlers in applications making use + of tags cannot rely on the tag information for user virtual + addresses being maintained for fields inside siginfo_t. + One exception to this rule is for signals raised in response + to watchpoint debug exceptions, where the tag information will be preserved. (3) Special care should be taken when using tagged pointers, since it is likely that C compilers will not hazard two - addresses differing only in the upper bits. + virtual addresses differing only in the upper byte. The architecture prevents the use of a tagged PC, so the upper byte will be set to a sign-extension of bit 55 on exception return. -- cgit v1.2.3 From 519192aaae38e24d6b32d3d55d791fe294981185 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Mon, 9 Sep 2013 17:32:56 +0200 Subject: KVM: Add documentation for kvm->srcu lock This patch documents the kvm->srcu lock (using the information from a mail which has been posted by Marcelo Tosatti to the kvm mailing list some months ago, see the following URL for details: http://www.mail-archive.com/kvm@vger.kernel.org/msg90040.html ) Signed-off-by: Thomas Huth Reviewed-by: Xiao Guangrong Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/locking.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index 41b7ac9884b5..a9f366e73c8e 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -151,3 +151,14 @@ Type: spinlock_t Arch: any Protects: -shadow page/shadow tlb entry Comment: it is a spinlock since it is used in mmu notifier. + +Name: kvm->srcu +Type: srcu lock +Arch: any +Protects: - kvm->memslots + - kvm->buses +Comment: The srcu read lock must be held while accessing memslots (e.g. + when using gfn_to_* functions) and while accessing in-kernel + MMIO/PIO address->device structure mapping (kvm->buses). + The srcu index can be stored in kvm_vcpu->srcu_idx per vcpu + if it is needed by multiple functions. -- cgit v1.2.3 From 56aba608257b451f663d25313d5ecae134d5557f Mon Sep 17 00:00:00 2001 From: Raghavendra K T Date: Thu, 12 Sep 2013 13:00:11 +0530 Subject: Documentation/kvm: Update cpuid documentation for steal time and pv eoi Thanks Michael S Tsirkin for rewriting the description and suggestions. Signed-off-by: Raghavendra K T Acked-by: Michael S. Tsirkin Signed-off-by: Gleb Natapov --- Documentation/virtual/kvm/cpuid.txt | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt index 22ff659bc0fb..3c65feb83010 100644 --- a/Documentation/virtual/kvm/cpuid.txt +++ b/Documentation/virtual/kvm/cpuid.txt @@ -43,6 +43,13 @@ KVM_FEATURE_CLOCKSOURCE2 || 3 || kvmclock available at msrs KVM_FEATURE_ASYNC_PF || 4 || async pf can be enabled by || || writing to msr 0x4b564d02 ------------------------------------------------------------------------------ +KVM_FEATURE_STEAL_TIME || 5 || steal time can be enabled by + || || writing to msr 0x4b564d03. +------------------------------------------------------------------------------ +KVM_FEATURE_PV_EOI || 6 || paravirtualized end of interrupt + || || handler can be enabled by writing + || || to msr 0x4b564d04. +------------------------------------------------------------------------------ KVM_FEATURE_PV_UNHALT || 7 || guest checks this feature bit || || before enabling paravirtualized || || spinlock support. -- cgit v1.2.3 From 4a937f96f3a29c58b7edd349d2e4dfac371efdf2 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Tue, 10 Sep 2013 12:58:35 +0200 Subject: KVM: protect kvm_usage_count with its own spinlock The VM list need not be protected by a raw spinlock. Separate the two so that kvm_lock can be made non-raw. Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/locking.txt | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index a9f366e73c8e..ba9e1c2150c2 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -135,7 +135,11 @@ Name: kvm_lock Type: raw_spinlock Arch: any Protects: - vm_list - - hardware virtualization enable/disable + +Name: kvm_count_lock +Type: raw_spinlock_t +Arch: any +Protects: - hardware virtualization enable/disable Comment: 'raw' because hardware enabling/disabling must be atomic /wrt migration. -- cgit v1.2.3 From 2f303b74a62fb74983c0a66e2df353be963c527c Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 25 Sep 2013 13:53:07 +0200 Subject: KVM: Convert kvm_lock back to non-raw spinlock In commit e935b8372cf8 ("KVM: Convert kvm_lock to raw_spinlock"), the kvm_lock was made a raw lock. However, the kvm mmu_shrink() function tries to grab the (non-raw) mmu_lock within the scope of the raw locked kvm_lock being held. This leads to the following: BUG: sleeping function called from invalid context at kernel/rtmutex.c:659 in_atomic(): 1, irqs_disabled(): 0, pid: 55, name: kswapd0 Preemption disabled at:[] mmu_shrink+0x5c/0x1b0 [kvm] Pid: 55, comm: kswapd0 Not tainted 3.4.34_preempt-rt Call Trace: [] __might_sleep+0xfd/0x160 [] rt_spin_lock+0x24/0x50 [] mmu_shrink+0xec/0x1b0 [kvm] [] shrink_slab+0x17d/0x3a0 [] ? mem_cgroup_iter+0x130/0x260 [] balance_pgdat+0x54a/0x730 [] ? set_pgdat_percpu_threshold+0xa7/0xd0 [] kswapd+0x18f/0x490 [] ? get_parent_ip+0x11/0x50 [] ? __init_waitqueue_head+0x50/0x50 [] ? balance_pgdat+0x730/0x730 [] kthread+0xdb/0xe0 [] ? finish_task_switch+0x52/0x100 [] kernel_thread_helper+0x4/0x10 [] ? __init_kthread_worker+0x After the previous patch, kvm_lock need not be a raw spinlock anymore, so change it back. Reported-by: Paul Gortmaker Cc: kvm@vger.kernel.org Cc: gleb@redhat.com Cc: jan.kiszka@siemens.com Reviewed-by: Gleb Natapov Signed-off-by: Paolo Bonzini --- Documentation/virtual/kvm/locking.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/virtual/kvm/locking.txt b/Documentation/virtual/kvm/locking.txt index ba9e1c2150c2..f8869410d40c 100644 --- a/Documentation/virtual/kvm/locking.txt +++ b/Documentation/virtual/kvm/locking.txt @@ -132,7 +132,7 @@ See the comments in spte_has_volatile_bits() and mmu_spte_update(). ------------ Name: kvm_lock -Type: raw_spinlock +Type: spinlock_t Arch: any Protects: - vm_list -- cgit v1.2.3