Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-11-29 Thread Mike Hommey
On Fri, Nov 02, 2012 at 09:59:07PM +0100, Michael Kerrisk wrote: > John, > > A question at on one point: > > On Wed, Oct 3, 2012 at 12:38 AM, John Stultz wrote: > > On 10/02/2012 12:39 AM, NeilBrown wrote: > [...] > >> The SIGBUS interface could have some merit if it really reduces > >>

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-11-29 Thread Mike Hommey
On Fri, Nov 02, 2012 at 09:59:07PM +0100, Michael Kerrisk wrote: John, A question at on one point: On Wed, Oct 3, 2012 at 12:38 AM, John Stultz john.stu...@linaro.org wrote: On 10/02/2012 12:39 AM, NeilBrown wrote: [...] The SIGBUS interface could have some merit if it really reduces

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-11-03 Thread Michael Kerrisk
[CC += linux-api, since this is an API change.] Hi John, A couple of other questions that occurred to me... What are the expected/planned semantics of volatile ranges for mlocked pages? I noticed that Minchan's patch series (https://lwn.net/Articles/522154/) gives an error on attempt to mark

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-11-03 Thread Michael Kerrisk
[CC += linux-api, since this is an API change.] Hi John, A couple of other questions that occurred to me... What are the expected/planned semantics of volatile ranges for mlocked pages? I noticed that Minchan's patch series (https://lwn.net/Articles/522154/) gives an error on attempt to mark

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-11-02 Thread Michael Kerrisk
John, A question at on one point: On Wed, Oct 3, 2012 at 12:38 AM, John Stultz wrote: > On 10/02/2012 12:39 AM, NeilBrown wrote: [...] >> The SIGBUS interface could have some merit if it really reduces >> overhead. I >> worry about app bugs that could result from the non-deterministic >>

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-11-02 Thread Michael Kerrisk
John, A question at on one point: On Wed, Oct 3, 2012 at 12:38 AM, John Stultz john.stu...@linaro.org wrote: On 10/02/2012 12:39 AM, NeilBrown wrote: [...] The SIGBUS interface could have some merit if it really reduces overhead. I worry about app bugs that could result from the

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-09 Thread Minchan Kim
On Tue, Oct 09, 2012 at 02:30:03PM -0700, John Stultz wrote: > On 10/09/2012 01:07 AM, Mike Hommey wrote: > >Note it doesn't have to be a vs. situation. madvise could be an > >additional way to interface with volatile ranges on a given fd. > > > >That is, madvise doesn't have to mean anonymous

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-09 Thread John Stultz
On 10/09/2012 01:07 AM, Mike Hommey wrote: Note it doesn't have to be a vs. situation. madvise could be an additional way to interface with volatile ranges on a given fd. That is, madvise doesn't have to mean anonymous memory. As a matter of fact, MADV_WILLNEED/MADV_DONTNEED are usually used on

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-09 Thread Mike Hommey
On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: > fd based interfaces vs madvise: > In talking with Taras Glek, he pointed out that for his > needs, the fd based interface is a little annoying, as it > requires having to get access to tmpfs file and mmap it in, >

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-09 Thread Mike Hommey
On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: fd based interfaces vs madvise: In talking with Taras Glek, he pointed out that for his needs, the fd based interface is a little annoying, as it requires having to get access to tmpfs file and mmap it in,

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-09 Thread John Stultz
On 10/09/2012 01:07 AM, Mike Hommey wrote: Note it doesn't have to be a vs. situation. madvise could be an additional way to interface with volatile ranges on a given fd. That is, madvise doesn't have to mean anonymous memory. As a matter of fact, MADV_WILLNEED/MADV_DONTNEED are usually used on

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-09 Thread Minchan Kim
On Tue, Oct 09, 2012 at 02:30:03PM -0700, John Stultz wrote: On 10/09/2012 01:07 AM, Mike Hommey wrote: Note it doesn't have to be a vs. situation. madvise could be an additional way to interface with volatile ranges on a given fd. That is, madvise doesn't have to mean anonymous memory. As a

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-08 Thread Minchan Kim
On Mon, Oct 08, 2012 at 06:25:07PM -0700, John Stultz wrote: > On 10/07/2012 11:25 PM, Minchan Kim wrote: > >Hi John, > > > >On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: > >>After Kernel Summit and Plumbers, I wanted to consider all the various > >>side-discussions and try to

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-08 Thread John Stultz
On 10/07/2012 11:25 PM, Minchan Kim wrote: Hi John, On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-08 Thread Minchan Kim
Hi John, On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: > > After Kernel Summit and Plumbers, I wanted to consider all the various > side-discussions and try to summarize my current thoughts here along > with sending out my current implementation for review. > > Also: I'm going on

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-08 Thread Minchan Kim
Hi John, On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current implementation for review. Also: I'm going on four

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-08 Thread John Stultz
On 10/07/2012 11:25 PM, Minchan Kim wrote: Hi John, On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-08 Thread Minchan Kim
On Mon, Oct 08, 2012 at 06:25:07PM -0700, John Stultz wrote: On 10/07/2012 11:25 PM, Minchan Kim wrote: Hi John, On Fri, Sep 28, 2012 at 11:16:30PM -0400, John Stultz wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-02 Thread John Stultz
On 10/02/2012 12:39 AM, NeilBrown wrote: On Fri, 28 Sep 2012 23:16:30 -0400 John Stultz wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current implementation for review.

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-02 Thread Taras Glek
On 9/28/2012 8:16 PM, John Stultz wrote: There is two rough approaches that I have tried so far 1) Managing volatile range objects, in a tree or list, which are then purged using a shrinker 2) Page based management, where pages marked volatile are moved to a new LRU list and are purged from

Re: [PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-10-02 Thread NeilBrown
On Fri, 28 Sep 2012 23:16:30 -0400 John Stultz wrote: > > After Kernel Summit and Plumbers, I wanted to consider all the various > side-discussions and try to summarize my current thoughts here along > with sending out my current implementation for review. > > Also: I'm going on four weeks of

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-02 Thread NeilBrown
On Fri, 28 Sep 2012 23:16:30 -0400 John Stultz john.stu...@linaro.org wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current implementation for review. Also: I'm going

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-02 Thread Taras Glek
On 9/28/2012 8:16 PM, John Stultz wrote: snip There is two rough approaches that I have tried so far 1) Managing volatile range objects, in a tree or list, which are then purged using a shrinker 2) Page based management, where pages marked volatile are moved to a new LRU list and are purged

Re: [PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-10-02 Thread John Stultz
On 10/02/2012 12:39 AM, NeilBrown wrote: On Fri, 28 Sep 2012 23:16:30 -0400 John Stultz john.stu...@linaro.org wrote: After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current

[PATCH 0/3] Volatile Ranges (v7) & Lots of words

2012-09-28 Thread John Stultz
After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current implementation for review. Also: I'm going on four weeks of paternity leave in the very near (but non-deterministic) future. So

[PATCH 0/3] Volatile Ranges (v7) Lots of words

2012-09-28 Thread John Stultz
After Kernel Summit and Plumbers, I wanted to consider all the various side-discussions and try to summarize my current thoughts here along with sending out my current implementation for review. Also: I'm going on four weeks of paternity leave in the very near (but non-deterministic) future. So