-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 12/01/2020 10.15, Andrei Borzenkov wrote: | 12.01.2020 11:57, jdd@dodin.org пишет: |> Le 11/01/2020 à 22:38, Carlos E. R. a écrit : |>> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 |>> |>> On 11/01/2020 22.15, jdd@dodin.org wrote: | Le 11/01/2020 à |>> 22:08, Carlos E. R. a écrit : | |> I said "not again". I |>> already did and it was a disaster. I *know* |> that it is |>> disastrous. |> | | just a question. | | What is the difference |>> between being short of real memory and being | short of memory |>> + swap? |>> |>> If you are short of memory but there is swap available, swap |>> will be used instead. |> | | That is wrong. In manner of speaking, no, because you say the same as I do. | |> sure, but do the kernel care that it's swap, not physical |> memory? |> |> in an other way, is 5 Gb of physical memory and 5 Gb of swap |> identical of 10Gb of physical memory? |> | | No. If there is no free memory to satisfy allocation request, | kernel will look for cold data in memory and will try to reclaim | it. Swap is used to preserve content of anonymous memory that is | reclaimed. Of course. | To actually *use* swapped out data kernel must read it back into | memory, which requires free memory so we are back to square one. Of course. | If no memory is available or can be reclaimed at this moment, data | cannot be read back and so cannot be used. | | And of course not all memory content can actually be swapped out in | the first place. Of course. | | So no, swap is not memory extension. | | Oh, and not every reclaimed memory needs swap (which is why I said | "anonymous" above). So even without swap it is possible to have | more virtual memory in use than is physically available. | |> if there is no difference, crash will happen whatever swap is |> created in a time where ram is nearly as big as disk space... |> |> jdd |> |> | | - -- Cheers / Saludos, Carlos E. R. (from 15.1 x86_64 at Telcontar) -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQQZEb51mJKK1KpcU/W1MxgcbY1H1QUCXhr01AAKCRC1MxgcbY1H 1e2KAJwNQ+kT515JeJvn/YmbK0JhlCxHWQCeN24VtQTHttqRTJsZ2FrtiO1qGVc= =g2jy -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org