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Use pmap_extract_and_hold() in pipe_build_write_buffer(). Consequently,

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pipe_build_write_buffer() no longer requires Giant on entry.

Reviewed by:	tegge
This commit is contained in:
Alan Cox 2003-09-08 04:58:32 +00:00
parent 20512f29f2
commit 03be99d20c
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=119872
1 changed files with 11 additions and 35 deletions
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46
sys/kern/sys_pipe.c
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@ -142,21 +142,6 @@ static struct filterops pipe_rfiltops =
static struct filterops pipe_wfiltops =
{ 1, NULL, filt_pipedetach, filt_pipewrite };
#define PIPE_GET_GIANT(pipe) \
do { \
KASSERT(((pipe)->pipe_state & PIPE_LOCKFL) != 0, \
("%s:%d PIPE_GET_GIANT: line pipe not locked", \
__FILE__, __LINE__)); \
PIPE_UNLOCK(pipe); \
mtx_lock(&Giant); \
} while (0)
#define PIPE_DROP_GIANT(pipe) \
do { \
mtx_unlock(&Giant); \
PIPE_LOCK(pipe); \
} while (0)
/*
* Default pipe buffer size(s), this can be kind-of large now because pipe
* space is pageable. The pipe code will try to maintain locality of
@ -655,46 +640,37 @@ pipe_build_write_buffer(wpipe, uio)
struct pipe *wpipe;
struct uio *uio;
{
pmap_t pmap;
u_int size;
int i;
int i, j;
vm_offset_t addr, endaddr;
vm_paddr_t paddr;
GIANT_REQUIRED;
PIPE_LOCK_ASSERT(wpipe, MA_NOTOWNED);
size = (u_int) uio->uio_iov->iov_len;
if (size > wpipe->pipe_buffer.size)
size = wpipe->pipe_buffer.size;
pmap = vmspace_pmap(curproc->p_vmspace);
endaddr = round_page((vm_offset_t)uio->uio_iov->iov_base + size);
addr = trunc_page((vm_offset_t)uio->uio_iov->iov_base);
for (i = 0; addr < endaddr; addr += PAGE_SIZE, i++) {
vm_page_t m;
/*
* vm_fault_quick() can sleep. Consequently,
* vm_page_lock_queue() and vm_page_unlock_queue()
* should not be performed outside of this loop.
*/
if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0 ||
(paddr = pmap_extract(vmspace_pmap(curproc->p_vmspace),
addr)) == 0) {
int j;
race:
if (vm_fault_quick((caddr_t)addr, VM_PROT_READ) < 0) {
vm_page_lock_queues();
for (j = 0; j < i; j++) {
for (j = 0; j < i; j++)
vm_page_unhold(wpipe->pipe_map.ms[j]);
}
vm_page_unlock_queues();
return (EFAULT);
}
m = PHYS_TO_VM_PAGE(paddr);
vm_page_lock_queues();
vm_page_hold(m);
vm_page_unlock_queues();
wpipe->pipe_map.ms[i] = m;
wpipe->pipe_map.ms[i] = pmap_extract_and_hold(pmap, addr);
if (wpipe->pipe_map.ms[i] == NULL)
goto race;
}
/*
@ -846,9 +822,9 @@ pipe_direct_write(wpipe, uio)
wpipe->pipe_state |= PIPE_DIRECTW;
pipelock(wpipe, 0);
PIPE_GET_GIANT(wpipe);
PIPE_UNLOCK(wpipe);
error = pipe_build_write_buffer(wpipe, uio);
PIPE_DROP_GIANT(wpipe);
PIPE_LOCK(wpipe);
pipeunlock(wpipe);
if (error) {
wpipe->pipe_state &= ~PIPE_DIRECTW;