Commit Graph

32 Commits

Author SHA1 Message Date
alc
e6c77ecaea Remove page queues locking from all sf_buf_mext()-like functions. The page
lock now suffices.

Fix a couple nearby style violations.
2010-05-06 17:43:41 +00:00
alc
c9aaa1e2a2 Add page locking to the vm_page_cow* functions.
Push down the acquisition and release of the page queues lock into
vm_page_wire().

Reviewed by:	kib
2010-05-04 15:55:41 +00:00
alc
387e15c45a This is the first step in transitioning responsibility for synchronizing
access to the page's wire_count from the page queues lock to the page lock.

Submitted by:	kmacy
2010-05-03 05:41:50 +00:00
kmacy
1dc1263413 On Alan's advice, rather than do a wholesale conversion on a single
architecture from page queue lock to a hashed array of page locks
(based on a patch by Jeff Roberson), I've implemented page lock
support in the MI code and have only moved vm_page's hold_count
out from under page queue mutex to page lock. This changes
pmap_extract_and_hold on all pmaps.

Supported by: Bitgravity Inc.

Discussed with: alc, jeffr, and kib
2010-04-30 00:46:43 +00:00
kib
ac1b596fda Extend the struct vm_page wire_count to u_int to avoid the overflow
of the counter, that may happen when too many sendfile(2) calls are
being executed with this vnode [1].

To keep the size of the struct vm_page and offsets of the fields
accessed by out-of-tree modules, swap the types and locations
of the wire_count and cow fields. Add safety checks to detect cow
overflow and force fallback to the normal copy code for zero-copy
sockets. [2]

Reported by:	Anton Yuzhaninov <citrin citrin ru> [1]
Suggested by:	alc [2]
Reviewed by:	alc
MFC after:	2 weeks
2009-01-03 13:24:08 +00:00
phk
df9c99b9c2 Give MEXTADD() another argument to make both void pointers to the
free function controlable, instead of passing the KVA of the buffer
storage as the first argument.

Fix all conventional users of the API to pass the KVA of the buffer
as the first argument, to make this a no-op commit.

Likely break the only non-convetional user of the API, after informing
the relevant committer.

Update the mbuf(9) manual page, which was already out of sync on
this point.

Bump __FreeBSD_version to 800016 as there is no way to tell how
many arguments a CPP macro needs any other way.

This paves the way for giving sendfile(9) a way to wait for the
passed storage to have been accessed before returning.

This does not affect the memory layout or size of mbufs.

Parental oversight by:	sam and rwatson.

No MFC is anticipated.
2008-02-01 19:36:27 +00:00
alc
7e0abcbfdf Previously, nothing prevented the page that was returned by pmap_extract()
from being reclaimed before it was wired.  Use pmap_extract_and_hold()
instead of pmap_extract() and retain the hold on the page until it has been
wired.
2005-10-23 07:41:56 +00:00
alc
9a35a868f7 Verify that access to the given address is allowed from user-space.
Discussed with: rwatson@
2005-10-22 20:02:59 +00:00
alc
2c640d0fff Eliminate spl* calls. 2005-10-21 05:48:38 +00:00
gallatin
c6980c2b7a Allow sends sent from non page-aligned userspace addresses to be
considered for zero-copy sends.

Reviewed by: alc
Submitted by: Romer Gil at Rice University
2005-06-05 17:13:23 +00:00
imp
20280f1431 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
alc
279c442e7b Introduce two new options, "CPU private" and "no wait", to sf_buf_alloc().
Change the spelling of the "catch" option to be consistent with the new
options.  Implement the "no wait" option.  An implementation of the "CPU
private" for i386 will be committed at a later date.
2004-11-08 00:43:46 +00:00
alc
1ec4d75266 In some cases, sf_buf_alloc() should sleep with pri PCATCH; in others, it
should not.  Add a new parameter so that the caller can specify which is
the case.

Reported by:	dillon
2004-04-03 09:16:27 +00:00
alc
d48f3c1617 Revise socow_iodone() in light of recent sf_buf changes. Specifically,
use sf_buf_free() instead of sf_buf_mext() to consolidate all actions
that require the page queues lock in one critical section.  While I'm
here remove unnecessary splvm() and splx() calls.
2004-03-17 23:25:04 +00:00
alc
a2e820d27b Refactor the existing machine-dependent sf_buf_free() into a machine-
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.
2004-03-16 19:04:28 +00:00
gallatin
13a64c8523 Handle sf_buf_alloc() returning null. This can happen if the
process takes a signal while waiting for an sf_buf to become available.

Reviewed by: alc
2004-01-17 21:16:51 +00:00
alc
74614e7f63 - Modify alpha's sf_buf implementation to use the direct virtual-to-
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.
2003-11-16 06:11:26 +00:00
obrien
3b8fff9e4c Use __FBSDID(). 2003-06-11 00:56:59 +00:00
alc
ae179e006f The data in an sf_buf should not be modified by the mbuf system. Mark
the mbuf as read only.

Reviewed by:	gallatin
2003-04-11 07:02:36 +00:00
alc
e1dab143cd Remove some dead code. 2003-04-08 18:24:28 +00:00
alc
6f59be774d Pass the vm_page's address to sf_buf_alloc(); map the vm_page as part
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().
2003-03-29 06:14:14 +00:00
jake
783ae539c3 - Add vm_paddr_t, a physical address type. This is required for systems
where physical addresses larger than virtual addresses, such as i386s
  with PAE.
- Use this to represent physical addresses in the MI vm system and in the
  i386 pmap code.  This also changes the paddr parameter to d_mmap_t.
- Fix printf formats to handle physical addresses >4G in the i386 memory
  detection code, and due to kvtop returning vm_paddr_t instead of u_long.

Note that this is a name change only; vm_paddr_t is still the same as
vm_offset_t on all currently supported platforms.

Sponsored by:	DARPA, Network Associates Laboratories
Discussed with:	re, phk (cdevsw change)
2003-03-25 00:07:06 +00:00
gallatin
d18eb82da5 Fix a race condition in socow_setup(): The page must be wired before
sf_buf_alloc() is called, as sf_buf_alloc() may sleep.  If it does sleep,
the page might be reclaimed before wiring occurs.

Reported by: alc
2003-03-18 18:27:33 +00:00
alc
4641d3d127 Pass the sf buf to MEXTADD() as the optional argument. This permits
the simplification of socow_iodone() and sf_buf_free(); they don't
have to reverse engineer the sf buf from the data's address.
2003-03-16 07:19:12 +00:00
alc
3a50d97c5c Remove some unnecessary actions by the zero-copy setup and teardown code.
Remove an incorrect comment.  (Incrementing an object's reference count
does not prevent a process from exiting.  The real concern here is that the
physical page must not be deleted until transmission is complete.  That is
already handled by the VM system and sf_buf_free().)

Tested by:	ken
2003-03-09 20:38:56 +00:00
mike
8630abe45f Change iov_base's type from char *' to the standard void *'. All
uses of iov_base which assume its type is `char *' (in order to do
pointer arithmetic) have been updated to cast iov_base to `char *'.
2002-10-11 14:58:34 +00:00
alc
0f13b0caca o Synchronize updates to struct vm_page::cow with the page queues lock. 2002-09-02 04:04:12 +00:00
dg
6dce2e7eff Moved sf_buf_alloc and sf_buf_free function declarations to sys/socketvar.h
so that they can be seen by external callers.
2002-08-13 19:03:19 +00:00
alc
93d5e16501 Lock accesses to the page queues. 2002-07-13 04:37:22 +00:00
gallatin
d7244e2c6d Remove the advertising clause from the Duke BSD copyright on the
zero-copy files

Requested by: rwatson
Approved by: Jeff Chase (my old boss at Duke)
2002-07-06 02:44:15 +00:00
alfred
d92411ce7a catch up with mextadd callback taking a void argument instead of a caddr_t. 2002-06-29 01:49:22 +00:00
ken
0d3a835f3f At long last, commit the zero copy sockets code.
MAKEDEV:	Add MAKEDEV glue for the ti(4) device nodes.

ti.4:		Update the ti(4) man page to include information on the
		TI_JUMBO_HDRSPLIT and TI_PRIVATE_JUMBOS kernel options,
		and also include information about the new character
		device interface and the associated ioctls.

man9/Makefile:	Add jumbo.9 and zero_copy.9 man pages and associated
		links.

jumbo.9:	New man page describing the jumbo buffer allocator
		interface and operation.

zero_copy.9:	New man page describing the general characteristics of
		the zero copy send and receive code, and what an
		application author should do to take advantage of the
		zero copy functionality.

NOTES:		Add entries for ZERO_COPY_SOCKETS, TI_PRIVATE_JUMBOS,
		TI_JUMBO_HDRSPLIT, MSIZE, and MCLSHIFT.

conf/files:	Add uipc_jumbo.c and uipc_cow.c.

conf/options:	Add the 5 options mentioned above.

kern_subr.c:	Receive side zero copy implementation.  This takes
		"disposable" pages attached to an mbuf, gives them to
		a user process, and then recycles the user's page.
		This is only active when ZERO_COPY_SOCKETS is turned on
		and the kern.ipc.zero_copy.receive sysctl variable is
		set to 1.

uipc_cow.c:	Send side zero copy functions.  Takes a page written
		by the user and maps it copy on write and assigns it
		kernel virtual address space.  Removes copy on write
		mapping once the buffer has been freed by the network
		stack.

uipc_jumbo.c:	Jumbo disposable page allocator code.  This allocates
		(optionally) disposable pages for network drivers that
		want to give the user the option of doing zero copy
		receive.

uipc_socket.c:	Add kern.ipc.zero_copy.{send,receive} sysctls that are
		enabled if ZERO_COPY_SOCKETS is turned on.

		Add zero copy send support to sosend() -- pages get
		mapped into the kernel instead of getting copied if
		they meet size and alignment restrictions.

uipc_syscalls.c:Un-staticize some of the sf* functions so that they
		can be used elsewhere.  (uipc_cow.c)

if_media.c:	In the SIOCGIFMEDIA ioctl in ifmedia_ioctl(), avoid
		calling malloc() with M_WAITOK.  Return an error if
		the M_NOWAIT malloc fails.

		The ti(4) driver and the wi(4) driver, at least, call
		this with a mutex held.  This causes witness warnings
		for 'ifconfig -a' with a wi(4) or ti(4) board in the
		system.  (I've only verified for ti(4)).

ip_output.c:	Fragment large datagrams so that each segment contains
		a multiple of PAGE_SIZE amount of data plus headers.
		This allows the receiver to potentially do page
		flipping on receives.

if_ti.c:	Add zero copy receive support to the ti(4) driver.  If
		TI_PRIVATE_JUMBOS is not defined, it now uses the
		jumbo(9) buffer allocator for jumbo receive buffers.

		Add a new character device interface for the ti(4)
		driver for the new debugging interface.  This allows
		(a patched version of) gdb to talk to the Tigon board
		and debug the firmware.  There are also a few additional
		debugging ioctls available through this interface.

		Add header splitting support to the ti(4) driver.

		Tweak some of the default interrupt coalescing
		parameters to more useful defaults.

		Add hooks for supporting transmit flow control, but
		leave it turned off with a comment describing why it
		is turned off.

if_tireg.h:	Change the firmware rev to 12.4.11, since we're really
		at 12.4.11 plus fixes from 12.4.13.

		Add defines needed for debugging.

		Remove the ti_stats structure, it is now defined in
		sys/tiio.h.

ti_fw.h:	12.4.11 firmware.

ti_fw2.h:	12.4.11 firmware, plus selected fixes from 12.4.13,
		and my header splitting patches.  Revision 12.4.13
		doesn't handle 10/100 negotiation properly.  (This
		firmware is the same as what was in the tree previously,
		with the addition of header splitting support.)

sys/jumbo.h:	Jumbo buffer allocator interface.

sys/mbuf.h:	Add a new external mbuf type, EXT_DISPOSABLE, to
		indicate that the payload buffer can be thrown away /
		flipped to a userland process.

socketvar.h:	Add prototype for socow_setup.

tiio.h:		ioctl interface to the character portion of the ti(4)
		driver, plus associated structure/type definitions.

uio.h:		Change prototype for uiomoveco() so that we'll know
		whether the source page is disposable.

ufs_readwrite.c:Update for new prototype of uiomoveco().

vm_fault.c:	In vm_fault(), check to see whether we need to do a page
		based copy on write fault.

vm_object.c:	Add a new function, vm_object_allocate_wait().  This
		does the same thing that vm_object allocate does, except
		that it gives the caller the opportunity to specify whether
		it should wait on the uma_zalloc() of the object structre.

		This allows vm objects to be allocated while holding a
		mutex.  (Without generating WITNESS warnings.)

		vm_object_allocate() is implemented as a call to
		vm_object_allocate_wait() with the malloc flag set to
		M_WAITOK.

vm_object.h:	Add prototype for vm_object_allocate_wait().

vm_page.c:	Add page-based copy on write setup, clear and fault
		routines.

vm_page.h:	Add page based COW function prototypes and variable in
		the vm_page structure.

Many thanks to Drew Gallatin, who wrote the zero copy send and receive
code, and to all the other folks who have tested and reviewed this code
over the years.
2002-06-26 03:37:47 +00:00