The previous code did not limit the I/O request size based on
the maximum number of segments supported by the back-end. In
current practice, since the only back-end supporting chained
requests is the FreeBSD implementation, this limit was never
exceeded.
sys/dev/xen/blkfront/block.h:
Add two macros, XBF_SEGS_TO_SIZE() and XBF_SIZE_TO_SEGS(),
to centralize the logic of reserving a segment to deal with
non-page-aligned I/Os.
sys/dev/xen/blkfront/blkfront.c:
o When negotiating transfer parameters, limit the
max_request_size we use and publish, if it is greater
than the maximum, unaligned, I/O we can support with
the number of segments advertised by the backend.
o Don't unilaterally reduce the I/O size published to
the disk layer by a single page. max_request_size
is already properly limited in the transfer parameter
negotiation code.
o Fix typos in printf strings:
"max_requests_segments" -> "max_request_segments"
"specificed" -> "specified"
MFC after: 1 day
- Make hash sizes growable, to satisfy users running large mpd
installations, having thousands of nodes.
- NG_NAMEHASH() proved to give a very bad distribution in real life
name sets, while generic hash32_str(name, HASHINIT) proved to give
an even one, so you the latter for name hash.
- Do not store unnamed nodes in slot 0 of name hash, no reason for that.
- Use the ID hash in cases when we need to run through all nodes: the
NGM_LISTNODES command and in the vnet_netgraph_uninit().
- Implement NGM_LISTNODES and NGM_LISTNAMES as separate code, the former
iterates through the ID hash, and the latter through the name hash.
- Keep count of all nodes and of named nodes, so that we don't need
to count nodes in NGM_LISTNODES and NGM_LISTNAMES. The counters are
also used to estimate whether we need to grow hashes.
- Close a race between two threads running ng_name_node() assigning same
name to different nodes.
messages were printed.
This can be enabled with the kern.msgbuf_show_timestamp sysctl
PR: kern/161553
Reviewed by: avg
Submitted by: Arnaud Lacombe <lacombar@gmail.com>
Approved by: cperciva
MFC after: 1 month
spinlock_enter()/spinlock_exit() to save/restore RFLAGS. We know interrupt
is disabled when returning from S3. For AP, we do not have to save/restore
it because IRET will do it for us any way. Do not save CR3 locally because
savectx() does it and BSP does not have to switch to kernel map for amd64.
Change contigmalloc(9) flag while I am in the neighborhood.
Introduce some functions to map NIC ring indexes into netmap ring
indexes and vice versa. This way we can implement the bound
checks only in one place (and hopefully in a correct way).
On passing, make the code and comments more uniform across the
various drivers.
Mask off the first 16 pages unless we appear to be running in a VM. This
address may be overridden by 'hw.physmem.start' tunable from loader.
Note Linux used to have a BIOS quirk table for this issue but it seems they
made it default recently.
hz >> 1000 and thus getting outside the timestamp clock frequenceny of
1ms < x < 1s per tick as mandated by RFC1323, leading to connection
resets on idle connections.
Always use a granularity of 1ms using getmicrouptime() making all but
relevant callouts independent of hz.
Use getmicrouptime(), not getmicrotime() as the latter may make a jump
possibly breaking TCP nfsroot mounts having our timestamps move forward
for more than 24.8 days in a second without having been idle for that
long.
PR: kern/61404
Reviewed by: jhb, mav, rrs
Discussed with: silby, lstewart
Sponsored by: Sandvine Incorporated (originally in 2011)
MFC after: 6 weeks
don't try probe and create EBR scheme when parent partition type
is not "ebr". This fixes error messages about corrupted EBR for
some partitions where is actually another partition scheme.
NOTE: if you have EBR on the partition with different than "ebr"
(0x05) type, then you will lost access to partitions until it will be
changed.
MFC after: 2 weeks
FreeBSD's front and back Xen blkif interface drivers.
sys/dev/xen/blkfront/block.h:
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
Replace FreeBSD specific multi-page ring impelementation with
support for both the Citrix and Amazon/RedHat versions of this
extension.
sys/dev/xen/blkfront/blkfront.c:
o Add a per-instance sysctl tree that exposes all negotiated
transport parameters (ring pages, max number of requests,
max request size, max number of segments).
o In blkfront_vdevice_to_unit() add a missing return statement
so that we properly identify the unit number for high numbered
xvd devices.
sys/dev/xen/blkback/blkback.c:
o Add static dtrace probes for several events in this driver.
o Defer connection shutdown processing until the front-end
enters the closed state. This avoids prematurely tearing
down the connection when buggy front-ends transition to the
closing state, even though the device is open and they
veto the close request from the tool stack.
o Add nodes for maximum request size and the number of active
ring pages to the exising, per-instance, sysctl tree.
o Miscelaneous style cleanup.
sys/xen/interface/io/blkif.h:
o Add extensive documentation of the XenStore nodes used to
implement the blkif interface.
o Document the startup sequence between a front and back driver.
o Add structures and documenatation for the "discard" feature
(AKA Trim).
o Cleanup some definitions related to FreeBSD's request
number/size/segment-limit extension.
sys/dev/xen/blkfront/blkfront.c:
sys/dev/xen/blkback/blkback.c:
sys/xen/xenbus/xenbusvar.h:
Add the convenience function xenbus_get_otherend_state() and
use it to simplify some logic in both block-front and block-back.
MFC after: 1 day
This allows LUNs greater than 0 to be probed. It can be increased later if
need be.
This brings back SVN rev 224973, which was inadvertently removed with the
import of the LSI driver.
Reported by: dwhite
MFC after: 3 days
