allocation and deallocation. This flag's principal use is shortly after
allocation. For such cases, clearing the flag is pointless. The only
unusual use of PG_ZERO is in vfs_bio_clrbuf(). However, allocbuf() never
requests a prezeroed page. So, vfs_bio_clrbuf() never sees a prezeroed
page.
Reviewed by: tegge@
side effect of that change caused headers to not be sent if a 0 byte
file was passed to sendfile. This change fixes that behavior, allowing
sendfile to send out the headers even with a 0 byte file again.
Noticed by: Dirk Engling
dependent function by the same name and a machine-independent function,
sf_buf_mext(). Aside from the virtue of making more of the code machine-
independent, this change also makes the interface more logical. Before,
sf_buf_free() did more than simply undo an sf_buf_alloc(); it also
unwired and if necessary freed the page. That is now the purpose of
sf_buf_mext(). Thus, sf_buf_alloc() and sf_buf_free() can now be used
as a general-purpose emphemeral map cache.
mindful of blocking on disk I/O and instead return EBUSY when such
blocking would occur.
Results from the DeBox project indicate that blocking on disk I/O
can slow the performance of a kqueue/poll based webserver. Using
a flag such as SF_NODISKIO and throwing connections that would block
to helper processes/threads helped increase performance.
Currently, only the Flash webserver uses this flag, although it could
probably be applied to thttpd with relative ease.
Idea by: Yaoping Ruan & Vivek Pai
packet along with data, instead of in their own packet. When serving files
of size (packetsize - headersize) or smaller, this will result in one less
packet crossing the network. Quick testing with thttpd and http_load has
shown a noticeable performance improvement in this case (350 vs 330 fetches
per second.)
Included in this commit are two support routines, iov_to_uio, and m_uiotombuf;
these routines are used by sendfile to construct the header mbuf chain that
will be linked to the rest of the data in the socket buffer.
in OpenBSD by Niels Provos. The patch introduces a bitmap of allocated
file descriptors which is used to locate available descriptors when a new
one is needed. It also moves the task of growing the file descriptor table
out of fdalloc(), reducing complexity in both fdalloc() and do_dup().
Debts of gratitude are owed to tjr@ (who provided the original patch on
which this work is based), grog@ (for the gdb(4) man page) and rwatson@
(for assistance with pxeboot(8)).
avoid relying on the minimum memory allocation size to avoid problems.
The check is somewhat redundant because the consumers of the returned
structure will check that sa_len is a protocol-specific larger size.
Submitted by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: nectar
MFC after: 30 days
to sendfile(2) being erroneously automatically restarted after a signal
is delivered. Fixed by converting ERESTART to EINTR prior to exiting.
Updated manual page to indicate the potential EINTR error, its cause
and consequences.
Approved by: re@freebsd.org
physical mapping.
- Move the sf_buf API to its own header file; make struct sf_buf's
definition machine dependent. In this commit, we remove an
unnecessary field from struct sf_buf on the alpha, amd64, and ia64.
Ultimately, we may eliminate struct sf_buf on those architecures
except as an opaque pointer that references a vm page.
table, acquiring the necessary locks as it works. It usually returns
two references to the new descriptor: one in the descriptor table
and one via a pointer argument.
As falloc releases the FILEDESC lock before returning, there is a
potential for a process to close the reference in the file descriptor
table before falloc's caller gets to use the file. I don't think this
can happen in practice at the moment, because Giant indirectly protects
closes.
To stop the file being completly closed in this situation, this change
makes falloc set the refcount to two when both references are returned.
This makes life easier for several of falloc's callers, because the
first thing they previously did was grab an extra reference on the
file.
Reviewed by: iedowse
Idea run past: jhb
sockets into machine-dependent files. The rationale for this
migration is illustrated by the modified amd64 allocator. It uses the
amd64's direct map to avoid emphemeral mappings in the kernel's
address space. On an SMP, the emphemeral mappings result in an IPI
for TLB shootdown for each transmitted page. Yuck.
Maintainers of other 64-bit platforms with direct maps should be able
to use the amd64 allocator as a reference implementation.
connection is to be established asynchronously, behave as in the
case of non-blocking mode:
- keep the SS_ISCONNECTING bit set thus indicating that
the connection establishment is in progress, which is the case
(clearing the bit in this case was just a bug);
- return EALREADY, instead of the confusing and unreasonable
EADDRINUSE, upon further connect(2) attempts on this socket
until the connection is established (this also brings our
connect(2) into accord with IEEE Std 1003.1.)
malloc and mbuf allocation all not requiring Giant.
1) ostat, fstat and nfstat don't need Giant until they call fo_stat.
2) accept can copyin the address length without grabbing Giant.
3) sendit doesn't need Giant, so don't bother grabbing it until kern_sendit.
4) move Giant grabbing from each indivitual recv* syscall to recvit.
does the copyin stuff and then calls the second part kern_sendit to do
the hard work. Don't bother holding Giant during the copyin phase.
The intent of this is to allow the Linux emulator to impliment send*
syscalls without using the stackgap.
of sf_buf_alloc() instead of expecting sf_buf_alloc()'s caller to map it.
The ultimate reason for this change is to enable two optimizations:
(1) that there never be more than one sf_buf mapping a vm_page at a time
and (2) 64-bit architectures can transparently use their 1-1 virtual
to physical mapping (e.g., "K0SEG") avoiding the overhead of pmap_qenter()
and pmap_qremove().
pointer types, and remove a huge number of casts from code using it.
Change struct xfile xf_data to xun_data (ABI is still compatible).
If we need to add a #define for f_data and xf_data we can, but I don't
think it will be necessary. There are no operational changes in this
commit.
