On Wed, 15 Jan 2020 18:23:05 +0530, Anupam Kapoor said:
>> On Wed, 15 Jan 2020 at 6:02 PM Sumit Kumar <sumit686215@xxxxxxxxx> wrote:
>>> Does C/C++ provide any API / system call that enables user to force the
>>> application to transfer some its physical pages to swap disk ? If so, is it
>>> also possible to obtain the least used page using some API ?
>> On Wed, 15 Jan 2020 at 6:02 PM Sumit Kumar <sumit686215@xxxxxxxxx> wrote:
>>> Does C/C++ provide any API / system call that enables user to force the
>>> application to transfer some its physical pages to swap disk ? If so, is it
>>> also possible to obtain the least used page using some API ?
>> would madvise not serve your needs ?
> There's this word "force" in the question.
> The problem is that madvise() is *advice* to the kernel, not a strict
> guarantee. There's a difference between "If you need to move pages
> to disk, consider these pages first" and "Move them to disk now, whether
> you really wanted to or not".
> There's this word "force" in the question.
> The problem is that madvise() is *advice* to the kernel, not a strict
> guarantee. There's a difference between "If you need to move pages
> to disk, consider these pages first" and "Move them to disk now, whether
> you really wanted to or not".
ofcourse (afaik) there is no way for the application to force the
*kernel* to do something like this.
*kernel* to do something like this.
but if _all_ that is required is randomly unmapping some marked
application pages, _that_ can be naively 'done' by the application
itself :)
for example, have a list of unmappable pages and an unmapper thread
which does the unmapping for you (picking any element in the list
at random)
--
kind regards
anupam
In the beginning was the lambda, and the lambda was with Emacs, and Emacs was the lambda.
On Sat, Jan 18, 2020 at 3:10 PM Valdis Klētnieks <valdis.kletnieks@xxxxxx> wrote:
On Wed, 15 Jan 2020 18:23:05 +0530, Anupam Kapoor said:
> On Wed, 15 Jan 2020 at 6:02 PM Sumit Kumar <sumit686215@xxxxxxxxx> wrote:
> > Does C/C++ provide any API / system call that enables user to force the
> > application to transfer some its physical pages to swap disk ? If so, is it
> > also possible to obtain the least used page using some API ?
> would madvise not serve your needs ?
There's this word "force" in the question.
The problem is that madvise() is *advice* to the kernel, not a strict
guarantee. There's a difference between "If you need to move pages
to disk, consider these pages first" and "Move them to disk now, whether
you really wanted to or not".
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