From: Cyril Hrubis <chrubis@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH] syscalls/getcpu: Add libc sched_getcpu() detection && fix compiler errors
Date: Fri, 12 Apr 2019 13:46:32 +0200 [thread overview]
Message-ID: <20190412114632.GD28648@haruka.lan> (raw)
In-Reply-To: <5CB06C84.8030900@cn.fujitsu.com>
Hi!
> >> -#if defined(__i386__)
> >> - return syscall(__NR_getcpu, cpu_id, node_id, cache_struct);
> >> +#ifndef HAVE_SCHED_GETCPU
> >> + return tst_syscall(__NR_getcpu, cpu_id, node_id, cache_struct);
> >> #else
> >> *cpu_id = sched_getcpu();
> >> #endif
> > So when __NR_getcpu is not implemented we end up with tst_brk(TCONF,
> > ...) called from the tst_syscall, right? Since AFAIK the getcpu syscall
> > is not implemented on all architectures...
> Yes. It will report TCONF if __NR_getcpu is not implemented.
>
> From getcpu manpage, it is not implemented on all architectures as you
> said, I think we can remove sched_getcpu and use __NR_getcpu directly.
Reading the manual pages I think it's correct to fall back to
sched_getcpu() since as far as I can tell platforms that don't support
getcpu syscall have implemented the functionality as vDSO. So unless we
implement vDSO variant of getcpu we have to rely on sched_getcpu().
--
Cyril Hrubis
chrubis@suse.cz
next prev parent reply other threads:[~2019-04-12 11:46 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-12 7:03 [LTP] [PATCH] syscalls/getcpu: Add libc sched_getcpu() detection && fix compiler errors Yang Xu
2019-04-12 9:43 ` Cyril Hrubis
2019-04-12 10:46 ` xuyang
2019-04-12 11:46 ` Cyril Hrubis [this message]
2019-04-15 5:39 ` xuyang
2019-04-17 6:05 ` [LTP] [PATCH v2 1/2] syscalls/sched_getaffinity: Cleanup && Convert to new API Yang Xu
2019-04-17 6:05 ` [LTP] [PATCH v2 2/2] syscalls/getcpu:Add libc sched_getcpu() detection &&fix compiler errors Yang Xu
2019-05-13 7:54 ` xuyang
2019-05-13 8:27 ` Petr Vorel
2019-05-13 8:55 ` Cyril Hrubis
2019-05-13 9:40 ` Petr Vorel
2019-04-18 15:27 ` [LTP] [PATCH v2 1/2] syscalls/sched_getaffinity: Cleanup && Convert to new API Cyril Hrubis
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