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author | netchild <netchild@FreeBSD.org> | 2006-10-15 14:22:14 +0000 |
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committer | netchild <netchild@FreeBSD.org> | 2006-10-15 14:22:14 +0000 |
commit | 183bd5a34bb7e6bdd1231cfafcc185bc5eb27d7f (patch) | |
tree | 37b5d24e960676debab482dc664dda0e3c7ec546 /sys/i386/linux/syscalls.master | |
parent | 7b28cc9b2faecf0b23e4e115f9cd784767065ea8 (diff) | |
download | FreeBSD-src-183bd5a34bb7e6bdd1231cfafcc185bc5eb27d7f.zip FreeBSD-src-183bd5a34bb7e6bdd1231cfafcc185bc5eb27d7f.tar.gz |
MFP4 (with some minor changes):
Implement the linux_io_* syscalls (AIO). They are only enabled if the native
AIO code is available (either compiled in to the kernel or as a module) at
the time the functions are used. If the AIO stuff is not available there
will be a ENOSYS.
From the submitter:
---snip---
DESIGN NOTES:
1. Linux permits a process to own multiple AIO queues (distinguished by
"context"), but FreeBSD creates only one single AIO queue per process.
My code maintains a request queue (STAILQ of queue(3)) per "context",
and throws all AIO requests of all contexts owned by a process into
the single FreeBSD per-process AIO queue.
When the process calls io_destroy(2), io_getevents(2), io_submit(2) and
io_cancel(2), my code can pick out requests owned by the specified context
from the single FreeBSD per-process AIO queue according to the per-context
request queues maintained by my code.
2. The request queue maintained by my code stores contrast information between
Linux IO control blocks (struct linux_iocb) and FreeBSD IO control blocks
(struct aiocb). FreeBSD IO control block actually exists in userland memory
space, required by FreeBSD native aio_XXXXXX(2).
3. It is quite troubling that the function io_getevents() of libaio-0.3.105
needs to use Linux-specific "struct aio_ring", which is a partial mirror
of context in user space. I would rather take the address of context in
kernel as the context ID, but the io_getevents() of libaio forces me to
take the address of the "ring" in user space as the context ID.
To my surprise, one comment line in the file "io_getevents.c" of
libaio-0.3.105 reads:
Ben will hate me for this
REFERENCE:
1. Linux kernel source code: http://www.kernel.org/pub/linux/kernel/v2.6/
(include/linux/aio_abi.h, fs/aio.c)
2. Linux manual pages: http://www.kernel.org/pub/linux/docs/manpages/
(io_setup(2), io_destroy(2), io_getevents(2), io_submit(2), io_cancel(2))
3. Linux Scalability Effort: http://lse.sourceforge.net/io/aio.html
The design notes: http://lse.sourceforge.net/io/aionotes.txt
4. The package libaio, both source and binary:
http://rpmfind.net/linux/rpm2html/search.php?query=libaio
Simple transparent interface to Linux AIO system calls.
5. Libaio-oracle: http://oss.oracle.com/projects/libaio-oracle/
POSIX AIO implementation based on Linux AIO system calls (depending on
libaio).
---snip---
Submitted by: Li, Xiao <intron@intron.ac>
Diffstat (limited to 'sys/i386/linux/syscalls.master')
-rw-r--r-- | sys/i386/linux/syscalls.master | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/sys/i386/linux/syscalls.master b/sys/i386/linux/syscalls.master index 61ba1d2..6b00584 100644 --- a/sys/i386/linux/syscalls.master +++ b/sys/i386/linux/syscalls.master @@ -409,11 +409,11 @@ 242 AUE_NULL UNIMPL linux_sched_getaffinity 243 AUE_NULL STD { int linux_set_thread_area(struct l_user_desc *desc); } 244 AUE_NULL STD { int linux_get_thread_area(struct l_user_desc *desc); } -245 AUE_NULL UNIMPL linux_io_setup -246 AUE_NULL UNIMPL linux_io_destroy -247 AUE_NULL UNIMPL linux_io_getevents -248 AUE_NULL UNIMPL linux_io_submit -249 AUE_NULL UNIMPL linux_io_cancel +245 AUE_NULL STD { int linux_io_setup(l_uint nr_reqs, linux_aio_context_t *ctxp); } +246 AUE_NULL STD { int linux_io_destroy(linux_aio_context_t ctx); } +247 AUE_NULL STD { int linux_io_getevents(linux_aio_context_t ctx_id, l_long min_nr, l_long nr, struct linux_io_event *events, struct l_timespec *timeout); } +248 AUE_NULL STD { int linux_io_submit(linux_aio_context_t ctx_id, l_long nr, struct linux_iocb **iocbpp); } +249 AUE_NULL STD { int linux_io_cancel(linux_aio_context_t ctx_id, struct linux_iocb *iocb, struct linux_io_event *result); } 250 AUE_NULL STD { int linux_fadvise64(void); } 251 AUE_NULL UNIMPL 252 AUE_EXIT STD { int linux_exit_group(int error_code); } |