blkif interface in Xen requires all I/O to be 512 byte aligned with each
segment bounded by a 4k page.
Note: This submission only documents the proper contraints for blkif I/O.
The alignment code in busdma does not yet handle alignment constraints
correctly in all cases.
the namecache records. The reclamation is not enabled by default because
for typical workload it would make namecache unusable, but large nested
directory tree easily puts any process that accesses filesystem into 1
second wait for vlru.
Reported by: yar (long time ago)
MFC after: 3 days
within ip_output, achieving (in random order of importance):
- a reduction of the number of 'r's in the source code;
- improved legibility;
- a reduction of 64 bytes in the .text
+ remove two unnecessary initializations in ip_output;
+ localize 'len';
+ introduce a temporary variable n to count the number of fragments,
the compiler seems unable to identify a common subexpression
(written 3 times, used twice);
+ document some assumptions on ip_len and ip_hl
r201011
- move most of ng_ipfw.h into ip_fw_private.h, as this code is
ipfw-specific. This removes a dependency on ng_ipfw.h from some files.
- move many equivalent definitions of direction (IN, OUT) for
reinjected packets into ip_fw_private.h
- document the structure of the packet tags used for dummynet
and netgraph;
r201049
- merge some common code to attach/detach hooks into
a single function.
r201055
- remove some duplicated code in ip_fw_pfil. The input
and output processing uses almost exactly the same code so
there is no need to use two separate hooks.
ip_fw_pfil.o goes from 2096 to 1382 bytes of .text
r201057 (see the svn log for full details)
- macros to make the conversion of ip_len and ip_off
between host and network format more explicit
r201113 (the remaining parts)
- readability fixes -- put braces around some large for() blocks,
localize variables so the compiler does not think they are uninitialized,
do not insist on precise allocation size if we have more than we need.
r201119
- when doing a lookup, keys must be in big endian format because
this is what the radix code expects (this fixes a bug in the
recently-introduced 'lookup' option)
No ABI changes in this commit.
MFC after: 1 week
