Thanks !! On 8/8/05, Thomas Petazzoni <thomas.petazzoni@xxxxxxxx> wrote: > Hi, > > Mulyadi Santosa wrote: > > > So why it is separated? IMHO the reason is to identify which process is > > kernel thread (doesn't own a process address space) and which one is > > normal process (owns a process address space). As you can see on > > functions related with context switching, by checking task_struct->mm, > > the scheduler can decide whether it is going to switch onto kernel > > thread or not. if > > There's one other reason for having both task->mm and task->active_mm: > in some cases, you might be executing a process without being in the > address space of that process. This is possible because during the > execution of a syscall, you're in kernel mode, so you don't necessarily > need to be in the correct address space. This avoids some costly TLB > switches. > > For more information, read section 4.3 of Mel Gorman's book at > http://www.phptr.com/content/images/0131453483/downloads/gorman_book.pdf. > > Sincerly, > > Thomas > -- > Thomas Petazzoni > thomas.petazzoni@xxxxxxxx > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
