21 | | * A vseg is '''public''' when it can be accessed by any thread of the process, whatever the cluster where the thread is running. It is '''private''' when it can only be accessed by the threads running in the cluster containing the physical memory bank where this vseg is mapped. A '''private''' vseg is entirely mapped in one single cluster K. It is registered in the VMM(P,K) segment list, but not in the other VMM(P,X) segment lists. |
22 | | |
23 | | * A vseg can be '''localised''' (all vseg pages are mapped in the same cluster), or '''distributed''' (different pages are mapped on different clusters, using the virtual page number (VPN) least significant bits as distribution key). A '''private''' vseg is always '''localised'''. |
| 21 | * A vseg is '''public''' when it can be accessed by any thread of the process, whatever the cluster where the thread is running. It is '''private''' when it can only be accessed by the threads running in the cluster containing the physical memory bank where this vseg is mapped. A '''private''' vseg is entirely mapped in one single cluster K. For a '''public''' vseg ALMOS-MK implement a global mapping : a virtual address is mapped to the same physical address in all clusters. For a '''private''' vessel, ALMOS-MK implement a local mapping : the same virtual address can be mapped to different physical addresses, in different clusters. |
| 22 | * A vseg can be '''localized''' (all vseg pages are mapped in the same cluster), or '''distributed''' (different pages are mapped on different clusters, using the virtual page number (VPN) least significant bits as distribution key). A '''private''' vseg is always '''localized'''. |
26 | | || type || || || || |
27 | | || CODE || private || localised || one per active cluster / same virtual addresses / same content || |
28 | | || DATA || public || distributed || one per process / replicated in all active clusters || |
29 | | || STACK || private || localised || one per thread / in same cluster as the thread || |
30 | | || MMAP || public || distributed || one per mmap(anon) || |
31 | | || FILE || public || localised || one per mmap(file) / in same cluster as the file || |
32 | | || MALLOC || public || distributed || used by the malloc() library / dynamically extensible || |
33 | | || REMOTE || public || localised || one per remote_malloc() / in cluster specified by user || |
| 25 | || type || || || || |
| 26 | || CODE || private || localized || Read Only one per cluster / replicated in all active clusters || |
| 27 | || DATA || public || distributed || Read/Write one per process / non replicated || |
| 28 | || HEAP || public || distributed || Read/Write one per process / non replicated || |
| 29 | || STACK || private || localized || Read/Write one per thread / in same cluster as the thread || |
| 30 | || MMAP || public || distributed || one per mmap(anon) || |
| 31 | || FILE || public || localized || one per mmap(file) / in same cluster as the file || |
| 32 | || REMOTE || public || localized || one per remote_mmap() / user defined placement || |
| 33 | |
| 34 | 1.'''CODE''' : This vseg contains the user application code. ALMOS-MK creates one CODE vseg per cluster. For a process P, the CODE vseg is registered in the VSL(P,Z) when the process is created in reference cluster Z. In the other clusters X, the CODE vseg is registered in VSL(P,X) when a page fault is signaled by a thread of P running in cluster X. |
| 35 | |
| 36 | 1. '''DATA''' : This vseg contains the user application global data. ALMOX-MK creates one single DATA vseg per process, that is registered in the reference VSL(P,Z) when the process P is created in reference cluster Z. In the other clusters X, the DATA vseg is registered in VSL(P,X) when a page fault is signaled by a thread of P running in cluster X. To avoid contention, this vseg is physically distributed on all clusters. For each page, the physical mapping is decided by the reference cluster Z, but the page can be mapped on any cluster Y. |
| 37 | |
| 38 | 1. '''STACK''' : For each thread T of process P running in cluster X, ALMOS_MK creates one STACK vseg. This vseg is registered in the VSL(P,X) when the thread descriptor is created in cluster X. To enforce locality, this vseg is physically mapped in cluster X. |
| 39 | |
| 40 | 1. '''HEAP''' This vseg is actually used by the malloc() library. ALMOX-MK creates one single HEAP vseg per process, that is registered in the reference VSL(P,Z) when the process P is created in reference cluster Z. In the other clusters X, the HEAP vseg is registered in VSL(P,X) when a page fault is signaled by a thread of P running in cluster X. To avoid contention, this vseg is physically distributed on all clusters. For each page, the physical mapping is decided by the reference cluster Z, but the page can be mapped on any cluster Y. |
| 41 | |
| 42 | 1. '''MMAP''' : This type of vseg is dynamically created by ALMOS-MK to serve an anonymous mmap() system call. |
| 43 | 1. '''FILE''' : This type of vseg is dynamically created by ALMOS-MK to serve an file based mmap() system call. This vseg being localized |
| 44 | 1. '''REMOTE''' : This type of vseg is dynamically created by ALMOS-MK to serve a remote_mmap() system call. |
| 45 | |
| 46 | |
| 47 | |