From 183bd5a34bb7e6bdd1231cfafcc185bc5eb27d7f Mon Sep 17 00:00:00 2001 From: netchild Date: Sun, 15 Oct 2006 14:22:14 +0000 Subject: 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 --- sys/i386/linux/linux.h | 2 ++ sys/i386/linux/syscalls.master | 10 +++++----- 2 files changed, 7 insertions(+), 5 deletions(-) (limited to 'sys/i386') diff --git a/sys/i386/linux/linux.h b/sys/i386/linux/linux.h index 9ad9353..1ca7381 100644 --- a/sys/i386/linux/linux.h +++ b/sys/i386/linux/linux.h @@ -803,4 +803,6 @@ typedef int l_mqd_t; #define THREADING_FLAGS (CLONE_VM | CLONE_FS | CLONE_FILES | CLONE_SIGHAND) +#include + #endif /* !_I386_LINUX_LINUX_H_ */ 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); } -- cgit v1.1