Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Benjamin LaHaise writes: > Today's high end systems are tomorrow's desktops... It probably makes Well, to some degree I agree with you. >100 processor high end systems have been around for a long time, but we still don't have those on the desktop. ;-) > sense to implement

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Benjamin LaHaise writes: > Today's high end systems are tomorrow's desktops... It probably makes Well, to some degree I agree with you. >100 processor high end systems have been around for a long time, but we still don't have those on the desktop. ;-) > sense to implement per-user limits

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Ben, On 10/05/2016 03:17 PM, Benjamin LaHaise wrote: Anything's possible when a local user can run code. [snip] That said, local users tend not to DoS themselves. Agree. I thought of something that could be particularly related to the aio implementation; but I guess there's nothing so

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Ben, On 10/05/2016 03:17 PM, Benjamin LaHaise wrote: Anything's possible when a local user can run code. [snip] That said, local users tend not to DoS themselves. Agree. I thought of something that could be particularly related to the aio implementation; but I guess there's nothing so

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Wed, Oct 05, 2016 at 02:58:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, > > On 10/05/2016 02:41 PM, Benjamin LaHaise wrote: > >I'd suggest increasing the default limit by changing how it is calculated. > >The current number came about 13 years ago when machines had orders of >

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Wed, Oct 05, 2016 at 02:58:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, > > On 10/05/2016 02:41 PM, Benjamin LaHaise wrote: > >I'd suggest increasing the default limit by changing how it is calculated. > >The current number came about 13 years ago when machines had orders of >

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Tue, Oct 04, 2016 at 07:55:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, Kent, and others, > > Would you please comment / answer about this possible problem? > Any feedback is appreciated. I'd suggest increasing the default limit by changing how it is calculated. The current

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Tue, Oct 04, 2016 at 07:55:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, Kent, and others, > > Would you please comment / answer about this possible problem? > Any feedback is appreciated. I'd suggest increasing the default limit by changing how it is calculated. The current

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Benjamin, On 10/05/2016 02:41 PM, Benjamin LaHaise wrote: I'd suggest increasing the default limit by changing how it is calculated. The current number came about 13 years ago when machines had orders of magnitude less RAM than they do today. Thanks for the suggestion. Does the default

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Benjamin, On 10/05/2016 02:41 PM, Benjamin LaHaise wrote: I'd suggest increasing the default limit by changing how it is calculated. The current number came about 13 years ago when machines had orders of magnitude less RAM than they do today. Thanks for the suggestion. Does the default

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Kent, Thanks for commenting. I understood more of the code in trying to make sense of your point, but there are some things still unclear about it; if you could help a bit more, please. Can you describe how a single thread might not be able to use all the slots because 'up to about half of

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Kent, Thanks for commenting. I understood more of the code in trying to make sense of your point, but there are some things still unclear about it; if you could help a bit more, please. Can you describe how a single thread might not be able to use all the slots because 'up to about half of

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Tue, Oct 04, 2016 at 07:55:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, Kent, and others, > > Would you please comment / answer about this possible problem? > Any feedback is appreciated. > > Since commit e1bdd5f27a5b ("aio: percpu reqs_available") the maximum > number of aio

Re: aio: questions with ioctx_alloc() and large num_possible_cpus()

On Tue, Oct 04, 2016 at 07:55:12PM -0300, Mauricio Faria de Oliveira wrote: > Hi Benjamin, Kent, and others, > > Would you please comment / answer about this possible problem? > Any feedback is appreciated. > > Since commit e1bdd5f27a5b ("aio: percpu reqs_available") the maximum > number of aio

aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Benjamin, Kent, and others, Would you please comment / answer about this possible problem? Any feedback is appreciated. Since commit e1bdd5f27a5b ("aio: percpu reqs_available") the maximum number of aio nr_events may be a function of num_possible_cpus() and actually be /inversely

aio: questions with ioctx_alloc() and large num_possible_cpus()

Hi Benjamin, Kent, and others, Would you please comment / answer about this possible problem? Any feedback is appreciated. Since commit e1bdd5f27a5b ("aio: percpu reqs_available") the maximum number of aio nr_events may be a function of num_possible_cpus() and actually be /inversely