Re: [algogeeks] OS problems
if there are 32 such frames of 8 X 1024 then the logical address will be (10+5)15 as pointed out by Harit. On Thu, Jul 1, 2010 at 8:57 AM, sharad kumar sharad20073...@gmail.comwrote: i think harit's answer is correct regarding ques 2 plzz someone comment on this -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
1. the virtual memory size depends on the page size that the system is using... 2. logical address=5+10=15 bits + (some modifying bits if they are present like modified,copied etc..) -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
@ above I think it is because of the heap size . The Heap corresponding to dynamic memory allocation grows and merges with the stack section of the process. Correct me if I am wrong. And if was only because of calloc() , then will malloc work? Can we allocate 1gb dynamically using malloc()?? On Sat, Jun 19, 2010 at 10:14 AM, harit agarwal agarwalha...@gmail.comwrote: @amit 1. calloc gives contiguos allocated space and it is not necessary that it can find 1gb in a row that's why it failed after allocating some memory... it is not necessary that it will always allocate 800mb of space as in this case... 2. whenever a process is executed in critical sectionit is means that it raises it execution level so that it can't be interrupted while the other processors are still on the same execution level they can be interrupted -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
for 1 other reasons apart 4m d 1 told by harit are 1)in every os,a user has maximum space allocated to him according to his previlege so ... may be it is exceeding that maximum capacity 2)it may be possible that it has exceeded total space available to whole os i.e it may be smaller system having much less physical memeory -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
yes you can allocate 1gb using malloc but it also depends on how much heap size is available to you.. if you try 2gb then more chances are it won't allocate because of heap is exhausted.. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
In SMP operating sytem provides spinlock to execute critical section of code that is shared among various processors. Spinlocks keeps every other processors just to spin around and there by prevents them from generating interrupts which could interrupt the processor which is executing the critical section. On Thu, Jun 17, 2010 at 12:39 PM, amit amitjaspal...@gmail.com wrote: 1. a mad user tries to allocate 1 gb memory using calloc. but the program fails after allocationg about 800mg(appx. i dont remember). Tell me what could have gone wrong? 2. We know disabling interrupts works only if it is single processor(i.e local disabling of interrupts). Consider this case where we have a SMP(symmetric multi proc) the processor. Processor-1 wants to perform some critical operation so it disables all the interrupts. What will happen when processor-2 throws an interrupt. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
@amit i think your query is answered by varun..as each process do system call to allocate memory so it is exhausting the memory for all the processesas all processes are having the same interface... @sharad 1.i don't think priviliges affect the user address spaceit tells that in which way the user can use that space 2.as you said may be whole memory available to OS 1 gb-this is the extreme case and also i don't think such kind of systems exist now... -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
can you explain what you meant when you said the program fails after allocationg about 800mg(appx. i dont remember). This is the excerpt from calloc man page, Calloc will either fail or succeed but there is no way you can tell so much was alloted and then it failed. *Return Value***For calloc() and malloc(), the value returned is a pointer to the allocated memory, which is suitably aligned for any kind of variable, or NULL if the request fails. On Fri, Jun 18, 2010 at 1:09 AM, amit amitjaspal...@gmail.com wrote: 1. a mad user tries to allocate 1 gb memory using calloc. but the program fails after allocationg about 800mg(appx. i dont remember). Tell me what could have gone wrong? 2. We know disabling interrupts works only if it is single processor(i.e local disabling of interrupts). Consider this case where we have a SMP(symmetric multi proc) the processor. Processor-1 wants to perform some critical operation so it disables all the interrupts. What will happen when processor-2 throws an interrupt. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
It means the program crashed while it was trying to allocate more memory . Now can u guess why that happened? On Fri, Jun 18, 2010 at 1:29 PM, jaladhi dave jaladhi.k.d...@gmail.comwrote: can you explain what you meant when you said the program fails after allocationg about 800mg(appx. i dont remember). This is the excerpt from calloc man page, Calloc will either fail or succeed but there is no way you can tell so much was alloted and then it failed. *Return Value***For calloc() and malloc(), the value returned is a pointer to the allocated memory, which is suitably aligned for any kind of variable, or NULL if the request fails. On Fri, Jun 18, 2010 at 1:09 AM, amit amitjaspal...@gmail.com wrote: 1. a mad user tries to allocate 1 gb memory using calloc. but the program fails after allocationg about 800mg(appx. i dont remember). Tell me what could have gone wrong? 2. We know disabling interrupts works only if it is single processor(i.e local disabling of interrupts). Consider this case where we have a SMP(symmetric multi proc) the processor. Processor-1 wants to perform some critical operation so it disables all the interrupts. What will happen when processor-2 throws an interrupt. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.comalgogeeks%2bunsubscr...@googlegroups.com . For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en. -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
Re: [algogeeks] OS problems
@amit 1. calloc gives contiguos allocated space and it is not necessary that it can find 1gb in a row that's why it failed after allocating some memory... it is not necessary that it will always allocate 800mb of space as in this case... 2. whenever a process is executed in critical sectionit is means that it raises it execution level so that it can't be interrupted while the other processors are still on the same execution level they can be interrupted -- You received this message because you are subscribed to the Google Groups Algorithm Geeks group. To post to this group, send email to algoge...@googlegroups.com. To unsubscribe from this group, send email to algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
