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| author | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2015-04-08 15:37:49 +0200 |
|---|---|---|
| committer | Sebastian Huber <sebastian.huber@embedded-brains.de> | 2015-05-20 09:58:21 +0200 |
| commit | 165dd8ea1256d71d6a4f52c0a66dcc2799ef8f99 (patch) | |
| tree | c42072a99573d4d7cc03b2263e2c0c6d53f9c691 /freebsd/sys/kern/sys_generic.c | |
| parent | rtems-bsd-chunk: Include missing header file (diff) | |
| download | rtems-libbsd-165dd8ea1256d71d6a4f52c0a66dcc2799ef8f99.tar.bz2 | |
Update to FreeBSD Stable/9 2015-04-08
Diffstat (limited to 'freebsd/sys/kern/sys_generic.c')
| -rw-r--r-- | freebsd/sys/kern/sys_generic.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/freebsd/sys/kern/sys_generic.c b/freebsd/sys/kern/sys_generic.c index eb1ed37d..0ed027d5 100644 --- a/freebsd/sys/kern/sys_generic.c +++ b/freebsd/sys/kern/sys_generic.c @@ -79,6 +79,20 @@ __FBSDID("$FreeBSD$"); #include <machine/rtems-bsd-syscall-api.h> #endif /* __rtems__ */ +/* + * The following macro defines how many bytes will be allocated from + * the stack instead of memory allocated when passing the IOCTL data + * structures from userspace and to the kernel. Some IOCTLs having + * small data structures are used very frequently and this small + * buffer on the stack gives a significant speedup improvement for + * those requests. The value of this define should be greater or equal + * to 64 bytes and should also be power of two. The data structure is + * currently hard-aligned to a 8-byte boundary on the stack. This + * should currently be sufficient for all supported platforms. + */ +#define SYS_IOCTL_SMALL_SIZE 128 /* bytes */ +#define SYS_IOCTL_SMALL_ALIGN 8 /* bytes */ + #ifndef __rtems__ int iosize_max_clamp = 1; SYSCTL_INT(_debug, OID_AUTO, iosize_max_clamp, CTLFLAG_RW, @@ -652,6 +666,7 @@ struct ioctl_args { int sys_ioctl(struct thread *td, struct ioctl_args *uap) { + u_char smalldata[SYS_IOCTL_SMALL_SIZE] __aligned(SYS_IOCTL_SMALL_ALIGN); u_long com; int arg, error; u_int size; @@ -686,17 +701,18 @@ sys_ioctl(struct thread *td, struct ioctl_args *uap) arg = (intptr_t)uap->data; data = (void *)&arg; size = 0; - } else - data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); + } else { + if (size > SYS_IOCTL_SMALL_SIZE) + data = malloc((u_long)size, M_IOCTLOPS, M_WAITOK); + else + data = smalldata; + } } else data = (void *)&uap->data; if (com & IOC_IN) { error = copyin(uap->data, data, (u_int)size); - if (error) { - if (size > 0) - free(data, M_IOCTLOPS); - return (error); - } + if (error != 0) + goto out; } else if (com & IOC_OUT) { /* * Zero the buffer so the user always @@ -710,7 +726,8 @@ sys_ioctl(struct thread *td, struct ioctl_args *uap) if (error == 0 && (com & IOC_OUT)) error = copyout(data, uap->data, (u_int)size); - if (size > 0) +out: + if (size > SYS_IOCTL_SMALL_SIZE) free(data, M_IOCTLOPS); return (error); } |