Re: [gentoo-user] Is my system (really) using nptl

[Michael Mol]

On Sun, Oct 14, 2012 at 5:31 AM, Florian Philipp <lists@×××××××××××.net> wrote:
> Am 14.10.2012 01:20, schrieb Michael Mol:
>> On Sat, Oct 13, 2012 at 4:18 PM, Canek Peláez Valdés <caneko@×××××.com> wrote:
>>> On Sat, Oct 13, 2012 at 2:50 PM, Michael Mol <mikemol@×××××.com> wrote:
>>> [snip]
>>>> (Well, I'm not certain that POSIX thinks of threads as parents to each other.
>>>
>>> Hence the reason I put "parent" in quotes, and I specified "actually,
>>> the thread that created it".
>>>
>>>> There are *numerous* IPC mechanisms available on Linux. For starters,
>>>> there are sockets (domain, IPv4, IPv6, et al), named pipes, signals,
>>>> mmap()'d files, messaging, etc.
>>>
>>> Yeah, none of them "easy and quickly" to use, or at least not if you
>>> compare it with shared memory.
>>
>> I assume you mean 'shared memory' in the 'many threads to an address
>> space', not the /dev/shm sense.
>>
>
> If we really want to be nit-picking, we have to assume 'shared memory'
> as in malloc'ed [1] or stack memory. Anonymous mmap'ed memory mappings
> are preserved across forks and changes in them can be shared since
> kernel 2.4.

Absolutely.

> [1] Yes, I know that malloc uses mmap but its mappings are MAP_PRIVATE.

For the GNU libc, yeah. I noticed that in strace, and was amused.

-- 
:wq