search for: holder

...in for a specified number of times (QSPIN_THRESHOLD >>> = 2^14) and then halted itself. The queue head waiter will spins >>> 2*QSPIN_THRESHOLD times before halting itself. When it has spinned >>> QSPIN_THRESHOLD times, the queue head will assume that the lock >>> holder may be scheduled out and attempt to kick the lock holder CPU >>> if it has the CPU number on hand. >> >> I don't really understand the reasoning for kicking the lock holder. > > I agree. If the lock holder isn't running, there's probably a good > reason f...

...in for a specified number of times (QSPIN_THRESHOLD >>> = 2^14) and then halted itself. The queue head waiter will spins >>> 2*QSPIN_THRESHOLD times before halting itself. When it has spinned >>> QSPIN_THRESHOLD times, the queue head will assume that the lock >>> holder may be scheduled out and attempt to kick the lock holder CPU >>> if it has the CPU number on hand. >> >> I don't really understand the reasoning for kicking the lock holder. > > I agree. If the lock holder isn't running, there's probably a good > reason f...

Dear R helpers Reproducible example: #warning - this causes a hard freeze on the machines I've tried it on matrix.holder<- matrix(rnorm(150), nrow=30, ncol=5) Out= expand.grid(matrix.holder[,1],matrix.holder[,2],matrix.holder[,3],matrix.holder[,4], matrix.holder[,5]) Problem: I'm running an analysis that I would like to do using a matrix containing all the possible combinations of the elements in a [30,5] m...

...e, the > lock waiters will spin for a specified number of times (QSPIN_THRESHOLD > = 2^14) and then halted itself. The queue head waiter will spins > 2*QSPIN_THRESHOLD times before halting itself. When it has spinned > QSPIN_THRESHOLD times, the queue head will assume that the lock > holder may be scheduled out and attempt to kick the lock holder CPU > if it has the CPU number on hand. I don't really understand the reasoning for kicking the lock holder. It will either be: running, runnable, or halted because it's in a slow path wait for another lock. In any of these stat...

...e, the > lock waiters will spin for a specified number of times (QSPIN_THRESHOLD > = 2^14) and then halted itself. The queue head waiter will spins > 2*QSPIN_THRESHOLD times before halting itself. When it has spinned > QSPIN_THRESHOLD times, the queue head will assume that the lock > holder may be scheduled out and attempt to kick the lock holder CPU > if it has the CPU number on hand. I don't really understand the reasoning for kicking the lock holder. It will either be: running, runnable, or halted because it's in a slow path wait for another lock. In any of these stat...

Within R I need to reformat my data so that the output looks like the following: " 7 WORDS 5550 3.14159 -6. 6." Previous folks were doing this by hand, but I would like to have a formula do it. That is, (a) 7 (place holder) on second column, then a space, (b) WORDS (placeholder) is a string descriptor that is left justified to column 4, (c) 5550 (place hoder) is right justified to column 26, (d) 3.14159 (place holder) is right justified to column 41, (e) -6. (place holder) is right justified to column 53, and (f)...

...'t know, it seems like this would fail for files in tmpdir...). Anyway... --- rsync-2.5.6-orig/receiver.c Mon Jan 20 23:32:17 2003 +++ rsync-2.5.6/receiver.c Mon Aug 25 10:13:37 2003 @@ -163,33 +163,51 @@ } } - static int get_tmpname(char *fnametmp, char *fname) { - char *f; + char *f, holder; + size_t len; + + if(strlen(fname) > MAXPATHLEN) { + rprintf(FERROR,"%s: filename too long\n", fname); + return 0; + } + + holder = 0; /* open tmp file */ if (tmpdir) { + int tlen; f = strrchr(fname,'/'); if (f == NULL) f = fname; else f++; - if (s...

...waiters will spin for a specified number of times (QSPIN_THRESHOLD >> = 2^14) and then halted itself. The queue head waiter will spins >> 2*QSPIN_THRESHOLD times before halting itself. When it has spinned >> QSPIN_THRESHOLD times, the queue head will assume that the lock >> holder may be scheduled out and attempt to kick the lock holder CPU >> if it has the CPU number on hand. > > I don't really understand the reasoning for kicking the lock holder. I agree. If the lock holder isn't running, there's probably a good reason for that and going to sleep...

The district a is the baseline and we observe the difference between District a & b is not significant, we can choose to combine these 2 values. How to write code to combine these 2 value ? > m1=glm(Claims~District+Group+Age+log(Holders),fami ly=poisson,data=mydata) > summary(m1) Call: glm(formula = Claims ~ District + Group + Age + log(Holders), family = poisson, data = mydata) Deviance Residuals: Min 1Q Median 3Q Max -2.553115 -0.471819 0.002411 0.455274 1.800739 Coefficients: Estimate Std. Error z value Pr(>|z|) (Inte...

I''m working on a new hypercall, do_confer, which allows the directed yielding of a vcpu to another vcpu. It is mainly used when a vcpu fails to acquire a spinlock, yielding to the lock holder instead of spinning. I ported the ppc64 spinlock implementation for the i386 linux portion. In implementing the hypercall, I''ve been trying to figure out how to get the scheduler (I''ve only played with bvt) to run the vcpu passed in the hypercall (after some validation) but I'...

...2:58 GMT+08:00 xinhui <xinhui.pan at linux.vnet.ibm.com>: > Hi, wanpeng > > On 2016?07?05? 17:57, Wanpeng Li wrote: >> >> Hi Xinhui, >> 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: >>> >>> This is to fix some lock holder preemption issues. Some other locks >>> implementation do a spin loop before acquiring the lock itself. Currently >>> kernel has an interface of bool vcpu_is_preempted(int cpu). It take the >>> cpu >>> as parameter and return true if the cpu is preempted. Then ke...

...2:58 GMT+08:00 xinhui <xinhui.pan at linux.vnet.ibm.com>: > Hi, wanpeng > > On 2016?07?05? 17:57, Wanpeng Li wrote: >> >> Hi Xinhui, >> 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: >>> >>> This is to fix some lock holder preemption issues. Some other locks >>> implementation do a spin loop before acquiring the lock itself. Currently >>> kernel has an interface of bool vcpu_is_preempted(int cpu). It take the >>> cpu >>> as parameter and return true if the cpu is preempted. Then ke...

...touch a second cacheline; add a pending > bit and allow a single in-word spinner before we punt to the second > cacheline. I think there is an unwanted scenario on virtual machines: 1) VCPU sets the pending bit and start spinning. 2) Pending VCPU gets descheduled. - we have PLE and lock holder isn't running [1] - the hypervisor randomly preempts us 3) Lock holder unlocks while pending VCPU is waiting in queue. 4) Subsequent lockers will see free lock with set pending bit and will loop in trylock's 'for (;;)' - the worst-case is lock starving [2] - PLE can s...

...touch a second cacheline; add a pending > bit and allow a single in-word spinner before we punt to the second > cacheline. I think there is an unwanted scenario on virtual machines: 1) VCPU sets the pending bit and start spinning. 2) Pending VCPU gets descheduled. - we have PLE and lock holder isn't running [1] - the hypervisor randomly preempts us 3) Lock holder unlocks while pending VCPU is waiting in queue. 4) Subsequent lockers will see free lock with set pending bit and will loop in trylock's 'for (;;)' - the worst-case is lock starving [2] - PLE can s...

Hi Xinhui, 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). It take the cpu > as parameter and return true if the cpu is preempted. Then kernel can break > the spin loops up...

Hi Xinhui, 2016-06-28 22:43 GMT+08:00 Pan Xinhui <xinhui.pan at linux.vnet.ibm.com>: > This is to fix some lock holder preemption issues. Some other locks > implementation do a spin loop before acquiring the lock itself. Currently > kernel has an interface of bool vcpu_is_preempted(int cpu). It take the cpu > as parameter and return true if the cpu is preempted. Then kernel can break > the spin loops up...

This patch adds para-virtualization support to the queue spinlock code by enabling the queue head to kick the lock holder CPU, if known, in when the lock isn't released for a certain amount of time. It also enables the mutual monitoring of the queue head CPU and the following node CPU in the queue to make sure that their CPUs will stay scheduled in. Signed-off-by: Waiman Long <Waiman.Long at hp.com> --- ar...

...a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g 400 -p && perf report 18.09% sched-messaging [kernel.vmlinux] [k] osq_lock 12.28% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 5.27% sched-messaging [kernel.vmlinux] [k] mutex_unlock 3.89% s...

...a simplier definition of default vcpu_is_preempted skip mahcine type check on ppc, and add config. remove dedicated macro. add one patch to drop overload of rwsem_spin_on_owner and mutex_spin_on_owner. add more comments thanks boqun and Peter's suggestion. This patch set aims to fix lock holder preemption issues. test-case: perf record -a perf bench sched messaging -g 400 -p && perf report 18.09% sched-messaging [kernel.vmlinux] [k] osq_lock 12.28% sched-messaging [kernel.vmlinux] [k] rwsem_spin_on_owner 5.27% sched-messaging [kernel.vmlinux] [k] mutex_unlock 3.89% s...

...c("mir", "gene", "score") data$mir = as.character(data$mir) data$gene = as.character(data$gene) #input miR of Interest mirs = c("hsa-miR-146a-5p", "hsa-miR-215") #create table of miR targets table = data.frame(data[0,]) for(i in 1:length(mirs)) { holder = subset(data, data$mir==mirs[i]) table = holder } The problem is that each time the loop runs, table is being overwritten by holder, and I can't create something like table[i,] = holder because length of i is equal to 2. Probably an easy solution but I am overthinking it at this point. Thank...