Re: [Haifux] SSD and linux

2008-09-18 Thread Muli Ben-Yehuda
On Thu, Sep 18, 2008 at 06:49:58PM +0300, Doron Zuckerman wrote: > Do you have any idea where we can find this? I haven't looked at those bits recently, but it sounds like Gabi is pointing you to the right path. In any case, to be honest, I think what you propose doesn't make sense, even as "res

Re: [Haifux] SSD and linux

2008-09-18 Thread Muli Ben-Yehuda
On Thu, Sep 18, 2008 at 06:56:09PM +0300, gabik wrote: > Doron > > You can work on 2.6.24 if you prefer. I just picked some version and checked > on it. (for some reason there is no arch/i386 in 2.6.24. Maybe they have > renamed it into x86?) Yes. arch/x86 is now for both 32 and 64 bits. Cheers

Re: [Haifux] SSD and linux

2008-09-18 Thread gabik
q->make_request_fn seems to call a function __make_request() [blk_init_queue_node initializes a pointer to this function] __make_request calls get_request_wait() which in turn calls prepare_to_wait_exclusive() and later io_schedule(). So the logic is exactly like in 2.6.11, but a bit more comple

Re: [Haifux] SSD and linux

2008-09-18 Thread gabik
Doron You can work on 2.6.24 if you prefer. I just picked some version and checked on it. (for some reason there is no arch/i386 in 2.6.24. Maybe they have renamed it into x86?) As for which function to use: What you want to change is not the place where the io request is done, but the place wh

Re: [Haifux] SSD and linux

2008-09-18 Thread Doron Zuckerman
Hi Muli, It seems like a good idea to check the time of a single block read against a single context switch, we'll try looking more into it. > Try to find the place where the faulting process is put to sleep and convert that code to busy wait instead, terminating the busy-wait when the page has b

Re: [Haifux] SSD and linux

2008-09-18 Thread Doron Zuckerman
Hi Gabi, First of all thanks for you're help. We are currently using kernel 2.6.24, and couldn't find any call to the function "block_wait_queue_running(q)" there. It seems to handle things a bit differently. Moreover I looked at the code of kernel 2.6.11 and from what I can understand, it seems

Re: [Haifux] SSD and linux

2008-09-18 Thread Muli Ben-Yehuda
On Thu, Sep 18, 2008 at 12:27:36PM +0300, Doron Zuckerman wrote: > I'm not sure it will speed up the OS, however I'm doing an academic > research on the matter as part of a project I'm taking, and I plan > to check this point. I'm pretty sure it won't. > The leading thought was that since the SS

Re: [Haifux] SSD and linux

2008-09-18 Thread gabik
Hi Doron The place where the current process goes to sleep and waits until the page is swapped in is indeed in generic_make_request() (called from submit_bio()) There is a call to block_wait_queue_running(q); which moves this process to wait and calls for schedule() [prepare_to_wait_exclusive() a

Re: [Haifux] SSD and linux

2008-09-18 Thread Doron Zuckerman
Hi Gabi and Muli, I'm sorry about the mistake- you understood me correctly. I'm not sure it will speed up the OS, however I'm doing an academic research on the matter as part of a project I'm taking, and I plan to check this point. The leading thought was that since the SSD is not a mechanical dri

Re: [Haifux] W2L + Installation party?

2008-09-18 Thread Shahar Dag
Hi Since SSDL is moving to Linux, and since we want our students to feel comfort with Linux We are willing to help with promotion of Linux I think (but I will have to check this) that: 1.. We can have an open day in SSDL. Students will be able to come and try Linux on our computers. Peo