By: sr (nobody.delete@this.nowhere.com), September 25, 2021 11:52 am
Room: Moderated Discussions
Linus Torvalds (torvalds.delete@this.linux-foundation.org) on September 25, 2021 11:31 am wrote:
> x86 segmentation is "free" only if you don't actually use them at all, and use only a small fixed set of segments
> that you can keep in the very limited segment cache (ie the four segment registers, plus CS/SS).
But isn't that just what you need for limited-access function?
Or how is it done in software? Enter into critical section where programmer(or compiler) wants code to operate in limited address range only? Can it set and properly maintained with less overhead? And after those side-channel band aids?
> x86 segmentation is "free" only if you don't actually use them at all, and use only a small fixed set of segments
> that you can keep in the very limited segment cache (ie the four segment registers, plus CS/SS).
But isn't that just what you need for limited-access function?
Or how is it done in software? Enter into critical section where programmer(or compiler) wants code to operate in limited address range only? Can it set and properly maintained with less overhead? And after those side-channel band aids?
| Topic | Posted By | Date |
|---|---|---|
| POWER10 SAP SD benchmark | anon2 | 2021/09/06 03:36 PM |
| POWER10 SAP SD benchmark | Daniel B | 2021/09/07 02:31 AM |
| "Cores" (and SPEC) | Rayla | 2021/09/07 07:51 AM |
| "Cores" (and SPEC) | anon | 2021/09/07 03:56 PM |
| POWER10 SAP SD benchmark | Anon | 2021/09/07 03:24 PM |
| POWER10 SAP SD benchmark | Anon | 2021/09/07 03:27 PM |
| Virtually tagged L1-caches | sr | 2021/09/08 05:49 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/08 08:22 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 08:56 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 08:58 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 10:09 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 10:46 AM |
| Virtually tagged L1-caches | sr | 2021/09/08 11:35 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/08 12:23 PM |
| Virtually tagged L1-caches | sr | 2021/09/08 12:40 PM |
| Virtually tagged L1-caches | anon | 2021/09/09 03:16 AM |
| Virtually tagged L1-caches | Konrad Schwarz | 2021/09/10 05:19 AM |
| Virtually tagged L1-caches | Hugo Décharnes | 2021/09/10 06:59 AM |
| Virtually tagged L1-caches | anon | 2021/09/14 03:17 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/14 09:34 AM |
| Or use a PLB (NT) | Paul A. Clayton | 2021/09/14 09:45 AM |
| Or use a PLB | Linus Torvalds | 2021/09/14 03:27 PM |
| Or use a PLB | anon | 2021/09/15 12:15 AM |
| Or use a PLB | Michael S | 2021/09/15 03:21 AM |
| Or use a PLB | dmcq | 2021/09/15 03:42 PM |
| Or use a PLB | Konrad Schwarz | 2021/09/16 04:24 AM |
| Or use a PLB | Michael S | 2021/09/16 10:13 AM |
| Or use a PLB | --- | 2021/09/16 01:02 PM |
| PLB reference | Paul A. Clayton | 2021/09/18 02:35 PM |
| PLB reference | Michael S | 2021/09/18 04:14 PM |
| Demand paging/translation orthogonal | Paul A. Clayton | 2021/09/19 07:33 AM |
| Demand paging/translation orthogonal | Michael S | 2021/09/19 09:10 AM |
| PLB reference | Carson | 2021/09/20 10:19 PM |
| PLB reference | sr | 2021/09/20 06:02 AM |
| PLB reference | Michael S | 2021/09/20 07:03 AM |
| PLB reference | Linus Torvalds | 2021/09/20 12:10 PM |
| Or use a PLB | sr | 2021/09/20 04:32 AM |
| Or use a PLB | sr | 2021/09/21 09:36 AM |
| Or use a PLB | Linus Torvalds | 2021/09/21 10:04 AM |
| Or use a PLB | sr | 2021/09/21 10:48 AM |
| Or use a PLB | Linus Torvalds | 2021/09/21 01:55 PM |
| Or use a PLB | sr | 2021/09/22 06:55 AM |
| Or use a PLB | rwessel | 2021/09/22 07:09 AM |
| Or use a PLB | Linus Torvalds | 2021/09/22 11:50 AM |
| Or use a PLB | sr | 2021/09/22 01:00 PM |
| Or use a PLB | dmcq | 2021/09/22 04:07 PM |
| Or use a PLB | Etienne Lorrain | 2021/09/23 08:50 AM |
| Or use a PLB | anon2 | 2021/09/22 04:09 PM |
| Or use a PLB | dmcq | 2021/09/23 02:35 AM |
| Or use a PLB | ⚛ | 2021/09/23 09:37 AM |
| Or use a PLB | Linus Torvalds | 2021/09/23 12:01 PM |
| Or use a PLB | gpd | 2021/09/24 03:59 AM |
| Or use a PLB | Linus Torvalds | 2021/09/24 10:45 AM |
| Or use a PLB | dmcq | 2021/09/24 12:43 PM |
| Or use a PLB | sr | 2021/09/25 10:19 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 10:44 AM |
| Or use a PLB | sr | 2021/09/25 11:11 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 11:31 AM |
| Or use a PLB | sr | 2021/09/25 11:52 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 12:05 PM |
| Or use a PLB | sr | 2021/09/25 12:23 PM |
| Or use a PLB | rwessel | 2021/09/25 03:29 PM |
| Or use a PLB | sr | 2021/10/01 12:22 AM |
| Or use a PLB | rwessel | 2021/10/01 06:19 AM |
| Or use a PLB | David Hess | 2021/10/01 10:35 AM |
| Or use a PLB | rwessel | 2021/10/02 04:47 AM |
| Or use a PLB | sr | 2021/10/02 11:16 AM |
| Or use a PLB | rwessel | 2021/10/02 11:53 AM |
| Or use a PLB | Linus Torvalds | 2021/09/25 11:57 AM |
| Or use a PLB | sr | 2021/09/25 12:07 PM |
| Or use a PLB | Linus Torvalds | 2021/09/25 12:21 PM |
| Or use a PLB | sr | 2021/09/25 12:40 PM |
| Or use a PLB | nksingh | 2021/09/27 09:07 AM |
| Or use a PLB | ⚛ | 2021/09/27 09:02 AM |
| Or use a PLB | Linus Torvalds | 2021/09/27 10:20 AM |
| Or use a PLB | Linus Torvalds | 2021/09/27 12:58 PM |
| Or use a PLB | dmcq | 2021/09/28 10:59 AM |
| Or use a PLB | sr | 2021/09/25 10:34 AM |
| Or use a PLB | rwessel | 2021/09/25 03:44 PM |
| Or use a PLB | sr | 2021/10/01 01:04 AM |
| Or use a PLB | rwessel | 2021/10/01 06:33 AM |
| I386 segmentation highlights | sr | 2021/10/04 07:53 AM |
| I386 segmentation highlights | Adrian | 2021/10/04 09:53 AM |
| I386 segmentation highlights | sr | 2021/10/04 10:19 AM |
| I386 segmentation highlights | rwessel | 2021/10/04 04:57 PM |
| I386 segmentation highlights | sr | 2021/10/05 11:16 AM |
| I386 segmentation highlights | Michael S | 2021/10/05 12:27 PM |
| I386 segmentation highlights | rwessel | 2021/10/05 04:20 PM |
| Or use a PLB | JohnG | 2021/09/25 10:18 PM |
| Or use a PLB | ⚛ | 2021/09/27 07:37 AM |
| Or use a PLB | Heikki Kultala | 2021/09/28 03:53 AM |
| Or use a PLB | rwessel | 2021/09/28 07:29 AM |
| Or use a PLB | David Hess | 2021/09/23 06:00 PM |
| Or use a PLB | Adrian | 2021/09/24 01:21 AM |
| Or use a PLB | dmcq | 2021/09/25 12:41 PM |
| Or use a PLB | blaine | 2021/09/26 11:19 PM |
| Or use a PLB | David Hess | 2021/09/27 11:35 AM |
| Or use a PLB | blaine | 2021/09/27 05:19 PM |
| Or use a PLB | Adrian | 2021/09/27 10:40 PM |
| Or use a PLB | Adrian | 2021/09/27 10:59 PM |
| Or use a PLB | dmcq | 2021/09/28 07:45 AM |
| Or use a PLB | rwessel | 2021/09/28 07:45 AM |
| Or use a PLB | David Hess | 2021/09/28 12:50 PM |
| Or use a PLB | Etienne Lorrain | 2021/09/30 01:25 AM |
| Or use a PLB | David Hess | 2021/10/01 10:40 AM |
| MMU privileges | sr | 2021/09/21 11:07 AM |
| MMU privileges | Linus Torvalds | 2021/09/21 01:49 PM |
| Virtually tagged L1-caches | Konrad Schwarz | 2021/09/16 04:18 AM |
| Virtually tagged L1-caches | Carson | 2021/09/16 01:12 PM |
| Virtually tagged L1-caches | anon2 | 2021/09/16 05:16 PM |
| Virtually tagged L1-caches | rwessel | 2021/09/16 06:29 PM |
| Virtually tagged L1-caches | sr | 2021/09/20 04:20 AM |
| Virtually tagged L1-caches | --- | 2021/09/08 02:28 PM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/08 08:28 PM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/08 08:34 PM |
| Virtually tagged L1-caches | --- | 2021/09/09 10:14 AM |
| Virtually tagged L1-caches | anonymou5 | 2021/09/09 10:44 PM |
| Multi-threading? | David Kanter | 2021/09/09 09:32 PM |
| Multi-threading? | --- | 2021/09/10 09:19 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 01:19 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 01:36 AM |
| Virtually tagged L1-caches | --- | 2021/09/11 09:53 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 12:43 AM |
| Virtually tagged L1-caches | Linus Torvalds | 2021/09/12 11:10 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 11:57 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/13 08:31 AM |
| Virtually tagged L1-caches | sr | 2021/09/20 04:11 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 02:49 AM |
| Virtually tagged L1-caches | Linus Torvalds | 2021/09/08 12:34 PM |
| Virtually tagged L1-caches | dmcq | 2021/09/09 02:46 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/09 02:58 AM |
| Virtually tagged L1-caches | sr | 2021/09/11 01:29 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/11 08:59 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 12:57 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/12 08:44 AM |
| Virtually tagged L1-caches | sr | 2021/09/12 09:48 AM |
| Virtually tagged L1-caches | dmcq | 2021/09/12 01:22 PM |
| Virtually tagged L1-caches | sr | 2021/09/20 04:40 AM |
| Where do you see this information? (NT) | anon2 | 2021/09/09 02:45 AM |
| Where do you see this information? | sr | 2021/09/11 01:40 AM |
| Where do you see this information? | anon2 | 2021/09/11 01:53 AM |
| Where do you see this information? | sr | 2021/09/11 02:08 AM |
| Thank you (NT) | anon2 | 2021/09/11 04:31 PM |