By: Travis Downs (travis.downs.delete@this.gmail.com), June 6, 2019 7:11 am
Room: Moderated Discussions
Jeff S. (fakity.delete@this.fake.com) on June 5, 2019 8:03 pm wrote:
> Just MAP_FIXED|MAP_POPULATE over page rages not mincore()? You're at least safe from mlock() ulimits then.
Yeah, this crossed my mind, but it seems a bit risky?
This will replace the existing mapping. If the new mmap has the same characteristics as the old one, I guess that is harmless, but I can't really be sure of how the pages were mapped in the first place and I feel like it could break when the allocator changes. Maybe the pages weren't even allocated with mmap in the first place, but rather [s]brk(2) or something like that (IIRC most allocators still try to use brk for at least some allocations).
> Just MAP_FIXED|MAP_POPULATE over page rages not mincore()? You're at least safe from mlock() ulimits then.
Yeah, this crossed my mind, but it seems a bit risky?
This will replace the existing mapping. If the new mmap has the same characteristics as the old one, I guess that is harmless, but I can't really be sure of how the pages were mapped in the first place and I feel like it could break when the allocator changes. Maybe the pages weren't even allocated with mmap in the first place, but rather [s]brk(2) or something like that (IIRC most allocators still try to use brk for at least some allocations).
| Topic | Posted By | Date |
|---|---|---|
| Pre-populating anonymous pages | Travis Downs | 2019/06/05 04:48 PM |
| Pre-populating anonymous pages | Jeff S. | 2019/06/05 08:03 PM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/06 07:11 AM |
| Pre-populating anonymous pages | Jeff S. | 2019/06/06 08:40 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/06 08:59 AM |
| Pre-populating anonymous pages | Jeff S. | 2019/06/06 09:19 AM |
| Pre-populating anonymous pages | Foo_ | 2019/06/06 12:30 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/06 06:59 AM |
| Pre-populating anonymous pages | Foo_ | 2019/06/06 07:56 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/06 09:02 AM |
| Pre-populating anonymous pages | Linus Torvalds | 2019/06/06 11:01 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/07 02:16 PM |
| Pre-populating anonymous pages | Brendan | 2019/06/08 02:55 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/08 08:18 AM |
| Pre-populating anonymous pages | Linus Torvalds | 2019/06/08 11:43 AM |
| Pre-populating anonymous pages | Brendan | 2019/06/09 03:29 AM |
| Pre-populating anonymous pages | Linus Torvalds | 2019/06/10 11:20 AM |
| Pre-populating anonymous pages | Travis Downs | 2019/06/17 09:18 AM |
| Pre-populating anonymous pages | Linus Torvalds | 2019/06/18 04:28 PM |