This corrects an error in r296947 in that it is not possible to assert
which thread holds a shared (or read) lock, but it is possible to assert
that one is held. Just not very useful.
MFC after: 1 week
Submitted by: wblock, jhb
Reviewed by: kib (earlier version), jhb, wblock
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D5659
SYSCTL_COUNTER_U64_ARRAY() macro.
- Add proper asserts to the SYSCTL_COUNTER_U64_ARRAY() macro that checks
the size of the first element of the array.
- Add an example to the counter(9) manual page how to use the
SYSCTL_COUNTER_U64_ARRAY() macro.
- Add some missing symbolic links for counter(9) while at it.
This is several year's worth of fail point upgrades done at EMC Isilon. They
are interdependent enough that it makes sense to put a single diff up for them.
Primarily, we added:
- Changing all mainline execution paths to be lockless, which lets us use fail
points in more sleep-sensitive areas, and allows more parallel execution
- A number of additional commands, including 'pause' that lets us do some
interesting deterministic repros of race conditions
- The ability to dump the stacks of all threads sleeping on a fail point
- A number of other API changes to allow marking up the fail point's context in
the code, and firing callbacks before and after execution
- A man page update
Submitted by: Matthew Bryan <matthew.bryan@isilon.com>
Reviewed by: cem (earlier version), jhb, kib, pho
With feedback from: bdrewery
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D5427
Since m_cat() may copy data from the second mbuf chain into the last mbuf
of the first chain, it may free the first mbuf of the second chain. Thus,
the second chain is not guaranteed to be valid after m_cat() returns.
Reviewed by: glebius
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D5497
taskqueue_enqueue() was changed to support both fast and non-fast
taskqueues 10 years ago in r154167. It has been a compat shim ever
since. It's time for the compat shim to go.
Submitted by: Howard Su <howard0su@gmail.com>
Reviewed by: sephe
Differential Revision: https://reviews.freebsd.org/D5131
Summary:
Many instances of bus_alloc_resource() simply use 0 and ~0 for start and end to
denote 'anywhere' with a given count. To clean this up, introduce a
bus_alloc_resource_anywhere() convenience function.
Bump __FreeBSD_version for the new API.
Reviewed By: jhb
Differential Revision: https://reviews.freebsd.org/D5370
Summary:
Migrate to using the semi-opaque type rman_res_t to specify rman resources. For
now, this is still compatible with u_long.
This is step one in migrating rman to use uintmax_t for resources instead of
u_long.
Going forward, this could feasibly be used to specify architecture-specific
definitions of resource ranges, rather than baking a specific integer type into
the API.
This change has been broken out to facilitate MFC'ing drivers back to 10 without
breaking ABI.
Reviewed By: jhb
Sponsored by: Alex Perez/Inertial Computing
Differential Revision: https://reviews.freebsd.org/D5075
control algorithm options. The argument is variable length and is opaque
to TCP, forwarded directly to the algorithm's ctl_output method.
Provide new includes directory netinet/cc, where algorithm specific
headers can be installed.
The new API doesn't yet have any in tree consumers.
The original code written by lstewart.
Reviewed by: rrs, emax
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D711
This API has no in-tree consumers at the moment but is useful to at least
one out-of-tree consumer, and naturally complements existing vnode refcount
functions (vholdl(9), vdropl(9)).
Obtained from: kib (sys/ portion)
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D4947
Differential Revision: https://reviews.freebsd.org/D4953
Immediate problem fixed by the new KPI is the long-standing race
between device creation and assignments to cdev->si_drv1 and
cdev->si_drv2, which allows the window where cdevsw methods might be
called with si_drv1,2 fields not yet set. Devices typically checked
for NULL and returned spurious errors to usermode, and often left some
methods unchecked.
The new function interface is designed to be extensible, which should
allow to add more features to make_dev_s(9) without inventing yet
another name for function to create devices, while maintaining KPI and
even KBI backward-compatibility.
Reviewed by: hps, jhb
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D4746
While here, explicitly note the requirement that the BAR(s) must be
allocated prior to calling pci_alloc_msix().
Reviewed by: andrew, emaste
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D4688
exhausted.
It is possible for a bug in the code (or, theoretically, even unusual
network conditions) to exhaust all possible mbufs or mbuf clusters.
When this occurs, things can grind to a halt fairly quickly. However,
we currently do not call mb_reclaim() unless the entire system is
experiencing a low-memory condition.
While it is best to try to prevent exhaustion of one of the mbuf zones,
it would also be useful to have a mechanism to attempt to recover from
these situations by freeing "expendable" mbufs.
This patch makes two changes:
a) The patch adds a generic API to the UMA zone allocator to set a
function that should be called when an allocation fails because the
zone limit has been reached. Because of the way this function can be
called, it really should do minimal work.
b) The patch uses this API to try to free mbufs when an allocation
fails from one of the mbuf zones because the zone limit has been
reached. The function schedules a callout to run mb_reclaim().
Differential Revision: https://reviews.freebsd.org/D3864
Reviewed by: gnn
Comments by: rrs, glebius
MFC after: 2 weeks
Sponsored by: Juniper Networks
o With new KPI consumers can request contiguous ranges of pages, and
unlike before, all pages will be kept busied on return, like it was
done before with the 'reqpage' only. Now the reqpage goes away. With
new interface it is easier to implement code protected from race
conditions.
Such arrayed requests for now should be preceeded by a call to
vm_pager_haspage() to make sure that request is possible. This
could be improved later, making vm_pager_haspage() obsolete.
Strenghtening the promises on the business of the array of pages
allows us to remove such hacks as swp_pager_free_nrpage() and
vm_pager_free_nonreq().
o New KPI accepts two integer pointers that may optionally point at
values for read ahead and read behind, that a pager may do, if it
can. These pages are completely owned by pager, and not controlled
by the caller.
This shifts the UFS-specific readahead logic from vm_fault.c, which
should be file system agnostic, into vnode_pager.c. It also removes
one VOP_BMAP() request per hard fault.
Discussed with: kib, alc, jeff, scottl
Sponsored by: Nginx, Inc.
Sponsored by: Netflix
These helper functions can be used to read in or write a buffer from or to
an arbitrary process' address space. Without them, this can only be done
using proc_rwmem(), which requires the caller to fill out a uio. This is
onerous and results in code duplication; the new functions provide a simpler
interface which is sufficient for most existing callers of proc_rwmem().
This change also adds a manual page for proc_rwmem() and the new functions.
Reviewed by: jhb, kib
Differential Revision: https://reviews.freebsd.org/D4245
It was allowed before, but make it very explicit it is allowed now. And
prefer 'bool' to older types that were used for the same purpose -- int and
boolean_t.
Like with the C99 fixed-width types, use common sense when changing old
code.
No igor regressions.
Suggested by: bde <20151205031713.T3286@besplex.bde.org>
Reviewed by: glebius, davide, bapt (earlier versions)
Reviewed by: imp
Feedback from: julian
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D4384
like the various d_*_t typedefs since it declared a function pointer rather
than a function. Add a new d_priv_dtor_t typedef that declares the function
and can be used as a function prototype. The previous typedef wasn't
useful outside of the cdevpriv implementation, so retire it.
The name d_priv_dtor_t was chosen to be more consistent with cdev methods
since it is commonly used in place of d_close_t even though it is not a
direct pointer in struct cdevsw.
Reviewed by: kib, imp
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D4340
critical section.
uma_zalloc_arg()/uma_zalloc_free() may acquire a sleepable lock on the
zone. The malloc() family of functions may call uma_zalloc_arg() or
uma_zalloc_free().
The malloc(9) man page currently claims that free() will never sleep.
It also implies that the malloc() family of functions will not sleep
when called with M_NOWAIT. However, it is more correct to say that
these functions will not sleep indefinitely. Indeed, they may acquire
a sleepable lock. However, a developer may overlook this restriction
because the WITNESS check that catches attempts to call the malloc()
family of functions within a critical section is inconsistenly
applied.
This change clarifies the language of the malloc(9) man page to clarify
the restriction against calling the malloc() family of functions
while in a critical section or holding a spin lock. It also adds
KASSERTs at appropriate points to make the enforcement of this
restriction more consistent.
PR: 204633
Differential Revision: https://reviews.freebsd.org/D4197
Reviewed by: markj
Approved by: gnn (mentor)
Sponsored by: Juniper Networks
new return codes of -1 were mistakenly being considered "true". Callout_stop
now returns -1 to indicate the callout had either already completed or
was not running and 0 to indicate it could not be stopped. Also update
the manual page to make it more consistent no non-zero in the callout_stop
or callout_reset descriptions.
MFC after: 1 Month with associated callout change.
Igor has many less complaints now. I think the two remaining are bogus, but I
am also not sure why Igor is producing them.
The page still needs more work.
Sponsored by: EMC / Isilon Storage Division
should be used by TCP for sure in its cleanup of the IN-PCB (will be coming shortly).
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D4076
