rounding and overflow. Carefully document what the various overflow
tests actually detect.
The bugs mostly canceled out, such that the worst possible failure
cases resulted in non-fatal over-allocations.
than binary buddies, the alignment guarantees are weaker, which requires
a more complex aligned allocation algorithm, similar to that used for
alignment greater than the chunk size.
Reported by: matteo
chunks. This allows runs to be any multiple of the page size. The
primary advantage is that large objects are no longer constrained to be
2^n pages, which can dramatically decrease internal fragmentation for
large objects. This also allows the sizes for runs that back small
objects to be more finely tuned.
Free runs are searched for linearly using the chunk page map (with the
help of some heuristic optimizations). This changes the allocation
policy from "first best fit" to "first fit". A prototype red-black tree
implementation for tracking free runs that implemented "first best fit"
did not cause a measurable speed or memory usage difference for
realistic chunk sizes (though of course it is possible to construct
benchmarks that favor one allocation policy over another).
Refine the handling of fullness constraints for small runs to be more
tunable.
Restructure the per chunk page map to contain only two fields per entry,
rather than four. Also, increase each entry from 4 to 8 bytes, since it
allows for 32-bit integers, without increasing the number of chunk
header pages.
Relax the maximum chunk size constraint. This is of no practical
interest; it is merely fallout from the chunk page map restructuring.
Revamp statistics gathering and reporting to be faster, clearer and more
informative. Statistics gathering is fast enough now to have little
to no impact on application speed, but it still requires approximately
two extra pages of memory per arena (per process). This memory overhead
may be acceptable for most systems, but we still need to leave
statistics gathering disabled by default in RELENG branches.
Rename NO_MALLOC_EXTRAS to MALLOC_PRODUCTION in order to make its intent
clearer (i.e. it should be defined in RELENG branches).
avoid substantial potential bloat for static binaries that do not
otherwise use any printf(3)-family functions. [1]
Rearrange arena_run_t so that the region bitmask can be minimally sized
according to constraints related to each bin's size class. Previously,
the region bitmask was the same size for all run headers, which wasted
a measurable amount of memory.
Rather than making runs for small objects as large as possible, make
runs as small as possible such that header overhead stays below a
certain bound. There are two exceptions that override the header
overhead bound:
1) If the bound is impossible to honor, it is relaxed on a
per-size-class basis. Since there is one bit of header
overhead per object (plus a constant), it is impossible to
achieve a header overhead less than or equal to 1/(# of bits
per object). For the current setting of maximum 0.5% header
overhead, this relaxation comes into play for {2, 4, 8,
16}-byte objects, for which header overhead is (on 64-bit
systems) {7.1, 4.3, 2.2, 1.2}%, respectively.
2) There is still a cap on small run size, still set to 64kB.
This comes into play for {1024, 2048}-byte objects, for which
header overhead is {1.6, 3.1}%, respectively.
In practice, this reduces the run sizes, which makes worst case
low-water memory usage due to fragmentation less bad. It also reduces
worst case high-water run fragmentation due to non-full runs, but this
is only a constant improvement (most important to small short-lived
processes).
Reduce the default chunk size from 2MB to 1MB. Benchmarks indicate that
the external fragmentation reduction makes 1MB the new sweet spot (as
small as possible without adversely affecting performance).
Reported by: [1] kientzle
- moved away from ifn/ifa access to sctp_ifa/sctp_ifn
built and managed by the add-ip code.
- cleaned up add-ip code to use the iterator
- made iterator be a thread, which enables auto-asconf now.
- rewrote and cleaned up source address selection (also
made it use new structures).
- Fixed a couple of memory leaks.
- DACK now settable as to how many packets to delay as
well as time.
- connectx() to latest socket API, new associd arg.
- Fixed issue with revoking and loosing potential to
send when we inflate the flight size. We now inflate
the cwnd too and deflate it later when the revoked
chunk is sent or acked.
- Got rid of some temp debug code
- src addr selection moved to a common file (sctp_output.c)
- Support for simple VRF's (we have support for multi-vfr
via compile switch that is scrubbed from BSD but we won't
need multi-vrf until we first get VRF :-D)
- Rest of mib work for address information now done
- Limit number of addresses in INIT/INIT-ACK to
a #def (30).
Reviewed by: gnn
poll(2) or kqueue(2). Previously we rejected fd's higher than FD_SETSIZE
for kevent(2), and larger than sysconf(_SC_OPEN_MAX) for poll(2). However,
the check for poll(2) wasn't really needed. open(2) and socket(2) won't
return an fd you can't pass to either poll(2) or kevent(2). This fixes
a but where gethostbyname() would fail if you had more than 1023 files
open in a process.
MFC after: 1 week
Reviewed by: ume
Found by: ps
Add IMPLEMENTATION NOTES section explaining in detail the effect this
system call has in common use cases involving PF_INET and PF_INET6 sockets.
PR: kern/84761
MFC after: 2 days
behind _FREEFALL_CONFIG). This is done mainly to make NIS even more
resistant to packet loss.
This is not enabled by default for "normal" FreeBSD since it might cause
the server providing the RPC service to be hit heavily with RPC traffic
in case of problems. freefall.FreeBSD.org and hub.FreeBSD.org have been
running with a patch similar to this for a couple of weeks.
MFC after: 1 week
Discussed with: peter
packet loss when talking to a NIS server.
- Set 1 second retry timeout to further realistically handle UDP
packet loss for yp_next packet bursts. If the packet hasn't come
back within 1 second its rather unlikely to come back at all. There
is still back-off mechanism in RPC so if there is another reason
than packet loss for the lack of response within 1 second, the NIS
server will not be totally bombarded with requests.
This reduces the risk of NIS failing with:
yp_next: clnt_call: RPC: Timed out
considerably. This is mainly a problem if you have larger NIS maps
(like at FreeBSD.org) since enumerations of the lists will cause a UDP
packet bursts where a few packets being lost once in a while do
happen.
MFC after: 1 week
Discussed with: peter
Problem mainly diagnosed by: peter
in FreeBSD, and originated from INRIA IPv6.
Stub out netstat reference to addr2ascii() I mistakenly introduced.
Update misleading man page sections.
Merge NetBSD's getnameinfo() AF_LINK extensions for a portable way to
print link-layer addresses given a sockaddr_dl(), minus the IEEE 1394
bits which don't map directly to our code.
Obtained from: NetBSD (getnameinfo.c)
Discussed on: current (March 2006)
acl_from_text.c. Since acl_from_text.c is the only place it
is used, we can now make this internal utility function "static."
As a bonus, acl_set_fd() no longer pulls in getpwuid() for no reason.
MFC after: 7 days
This has no impact unless USE_BRK is defined (32-bit platforms), in
which case user allocations are allocated via mmap() if at all possible,
in order to avoid the possibility of unreclaimable chunks in the data
segment.
Fix an obscure bug in base_alloc() that could have allowed undefined
behavior if an application were to use sbrk() in conjunction with a
USE_BRK-enabled malloc.
called with only one address, we then can call the
generic system call. Also fixes some socket api
type issues and cleans up the "magic" numbers that
were being used in the code.
Reviewed by: gnn
Point out that FreeBSD libc has compat stubs for GNU glibc NSS
modules which access NSDB_PASSWD/NSDB_GROUP, but not NSDB_HOSTS;
based on painful experience porting nss_mdns.
Reviewed by: ru
number being returned for mktime and timegm calls. Choose 48 because
that works well. This does reduce the dynamic range of tm_year from
about 2 billion years down to "only" about 9 million years. Please
contact me if this restriction poses a problem.
Due to the complexity of the code, I admit that I didn't trace down
what, exactly, was overflowing with longer bits. This fixes software
that we run on the embedded systems we have.
effective group ID (and any of our group) doesn't match the group ID of the
file, we get EPERM. This doesn't conform POSIX. POSIX requires that we should
return 0, but silently clear the set-gid bit.
- O_NONBLOCK flag has to be set, if it is not set, open(2) will wait for
another process opening the fifo for reading,
- Use O_WRONLY which implies that the file has to be opened _only_ for write.
This is quite tricky situation, because we allow to open a file with
O_RDONLY|O_TRUNC. O_TRUNC modifies a file, but we actually don't open
it for writing. EISDIR is also returned when we try to open a directory
O_RDONLY|O_TRUNC, which is correct.
POSIX says that "The result of using O_TRUNC with O_RDONLY is undefined.",
we choose to accept it (Solaris did the same), that's why "to be modified"
seems more accurate to me.
conversion of negative numbers to always result in -1.
While at it, rearrange the nearby comment so it fits in 80 chars per line,
like the rest of this file does.
PR: 107130
MFC after: 1 day
chunk per arena, rather than immediately deallocating all unused chunks.
This fixes a potential performance issue when allocating/deallocating
an object of size (4kB..1MB] in a loop.
Reported by: davidxu
flag set, rmdir(2) returns EPERM.
- If the parent directory of the directory to be removed has its immutable or
append-only flag set, rmdir(2) returns EPERM.
immutable or append-only flag set, rename(2) returns EPERM.
- If the parent directory of the file pointed at by the to argument has its
immutable flag set, rename(2) returns EPERM.
