Re: arm ldxr/stxr vs cas

Liste des GroupesRevenir à c arch 
Sujet : Re: arm ldxr/stxr vs cas
De : chris.m.thomasson.1 (at) *nospam* gmail.com (Chris M. Thomasson)
Groupes : comp.arch
Date : 12. Sep 2024, 19:53:15
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vbvdar$c99f$1@dont-email.me>
References : 1 2 3 4 5 6 7 8 9
User-Agent : Mozilla Thunderbird
On 9/11/2024 7:33 AM, Stefan Monnier wrote:
I suspect at least theoretically conditions could exist where
having more than one lock within a cache line would be beneficial.
If lock B is always acquired after lock A, then sharing a cache
line might (I think) improve performance. One would lose
 I suspect in practice this almost never happens because if it did, it
would mean that the program would benefit from merging those two locks
into a single one.
Side note... Address based hash locking schemes can be used to emulate atomics in standard C++ when is_lock_free would be false. Here is one I did for fun:
https://en.cppreference.com/w/cpp/atomic/atomic/is_lock_free
It can merge locks into one wrt hash collisions, think of the hash algorithm. Sorting the locks and removing duplicates, taking the locks in order makes it deadlock free. Here is an example of such a locking scheme. I called it the multex:
https://groups.google.com/g/comp.lang.c++/c/sV4WC_cBb9Q/m/SkSqpSxGCAAJ
(read all when you get some time...)

Date Sujet#  Auteur
2 Sep 24 * arm ldxr/stxr vs cas58jseigh
2 Sep 24 +* Re: arm ldxr/stxr vs cas4Chris M. Thomasson
2 Sep 24 i`* Re: arm ldxr/stxr vs cas3Chris M. Thomasson
2 Sep 24 i `* Re: arm ldxr/stxr vs cas2jseigh
2 Sep 24 i  `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
4 Sep 24 +* Re: arm ldxr/stxr vs cas50MitchAlsup1
5 Sep 24 i+* Re: arm ldxr/stxr vs cas3Chris M. Thomasson
5 Sep 24 ii`* Re: arm ldxr/stxr vs cas2MitchAlsup1
5 Sep 24 ii `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
5 Sep 24 i`* Re: arm ldxr/stxr vs cas46jseigh
5 Sep 24 i +- Re: arm ldxr/stxr vs cas1Anton Ertl
5 Sep 24 i `* Re: arm ldxr/stxr vs cas44MitchAlsup1
5 Sep 24 i  `* Re: arm ldxr/stxr vs cas43Chris M. Thomasson
5 Sep 24 i   `* Re: arm ldxr/stxr vs cas42jseigh
6 Sep 24 i    +- Re: arm ldxr/stxr vs cas1MitchAlsup1
6 Sep 24 i    +* Re: arm ldxr/stxr vs cas20Chris M. Thomasson
6 Sep 24 i    i`* Re: arm ldxr/stxr vs cas19MitchAlsup1
7 Sep 24 i    i `* Re: arm ldxr/stxr vs cas18jseigh
8 Sep 24 i    i  `* Re: arm ldxr/stxr vs cas17Chris M. Thomasson
8 Sep 24 i    i   `* Re: arm ldxr/stxr vs cas16Chris M. Thomasson
8 Sep 24 i    i    `* Re: arm ldxr/stxr vs cas15Chris M. Thomasson
8 Sep 24 i    i     `* Re: arm ldxr/stxr vs cas14MitchAlsup1
8 Sep 24 i    i      +* Re: arm ldxr/stxr vs cas4Chris M. Thomasson
8 Sep 24 i    i      i+- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
8 Sep 24 i    i      i`* Re: arm ldxr/stxr vs cas2jseigh
8 Sep 24 i    i      i `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
8 Sep 24 i    i      `* Re: arm ldxr/stxr vs cas9Chris M. Thomasson
8 Sep 24 i    i       +* Re: arm ldxr/stxr vs cas6Michael S
8 Sep 24 i    i       i+- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
8 Sep 24 i    i       i+- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
9 Sep 24 i    i       i`* Re: arm ldxr/stxr vs cas3Michael S
9 Sep 24 i    i       i `* Re: arm ldxr/stxr vs cas2Michael S
9 Sep 24 i    i       i  `- Re: arm ldxr/stxr vs cas1Michael S
8 Sep 24 i    i       +- Re: arm ldxr/stxr vs cas1MitchAlsup1
8 Sep 24 i    i       `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
9 Sep 24 i    `* Re: arm ldxr/stxr vs cas20Terje Mathisen
9 Sep 24 i     +* Re: arm ldxr/stxr vs cas11jseigh
9 Sep 24 i     i+* Re: arm ldxr/stxr vs cas6Chris M. Thomasson
10 Sep 24 i     ii`* Re: arm ldxr/stxr vs cas5jseigh
10 Sep 24 i     ii `* Re: arm ldxr/stxr vs cas4Chris M. Thomasson
10 Sep 24 i     ii  `* Re: arm ldxr/stxr vs cas3jseigh
11 Sep 24 i     ii   `* Re: arm ldxr/stxr vs cas2Chris M. Thomasson
11 Sep 24 i     ii    `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
10 Sep 24 i     i`* Re: arm ldxr/stxr vs cas4Terje Mathisen
10 Sep 24 i     i `* Re: arm ldxr/stxr vs cas3jseigh
10 Sep 24 i     i  +- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
10 Sep 24 i     i  `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
9 Sep 24 i     +- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
11 Sep 24 i     `* Re: arm ldxr/stxr vs cas7Paul A. Clayton
11 Sep 24 i      +* Re: arm ldxr/stxr vs cas2Chris M. Thomasson
11 Sep 24 i      i`- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
11 Sep 24 i      +* Re: arm ldxr/stxr vs cas2jseigh
11 Sep 24 i      i`- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
11 Sep 24 i      `* Re: arm ldxr/stxr vs cas2Stefan Monnier
12 Sep 24 i       `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson
9 Sep 24 `* Re: arm ldxr/stxr vs cas3jseigh
11 Sep 24  `* Re: arm ldxr/stxr vs cas2jseigh
11 Sep 24   `- Re: arm ldxr/stxr vs cas1Chris M. Thomasson

Haut de la page

Les messages affichés proviennent d'usenet.

NewsPortal