These changes prevent sysctl(8) from returning proper output,
such as:
1) no output from sysctl(8)
2) erroneously returning ENOMEM with tools like truss(1)
or uname(1)
truss: can not get etype: Cannot allocate memory
there is an environment variable which shall initialize the SYSCTL
during early boot. This works for all SYSCTL types both statically and
dynamically created ones, except for the SYSCTL NODE type and SYSCTLs
which belong to VNETs. A new flag, CTLFLAG_NOFETCH, has been added to
be used in the case a tunable sysctl has a custom initialisation
function allowing the sysctl to still be marked as a tunable. The
kernel SYSCTL API is mostly the same, with a few exceptions for some
special operations like iterating childrens of a static/extern SYSCTL
node. This operation should probably be made into a factored out
common macro, hence some device drivers use this. The reason for
changing the SYSCTL API was the need for a SYSCTL parent OID pointer
and not only the SYSCTL parent OID list pointer in order to quickly
generate the sysctl path. The motivation behind this patch is to avoid
parameter loading cludges inside the OFED driver subsystem. Instead of
adding special code to the OFED driver subsystem to post-load tunables
into dynamically created sysctls, we generalize this in the kernel.
Other changes:
- Corrected a possibly incorrect sysctl name from "hw.cbb.intr_mask"
to "hw.pcic.intr_mask".
- Removed redundant TUNABLE statements throughout the kernel.
- Some minor code rewrites in connection to removing not needed
TUNABLE statements.
- Added a missing SYSCTL_DECL().
- Wrapped two very long lines.
- Avoid malloc()/free() inside sysctl string handling, in case it is
called to initialize a sysctl from a tunable, hence malloc()/free() is
not ready when sysctls from the sysctl dataset are registered.
- Bumped FreeBSD version to indicate SYSCTL API change.
MFC after: 2 weeks
Sponsored by: Mellanox Technologies
have to undo it by calling crfree(). This reduces the total number of calls
by vm_map_insert() to crhold() and crfree() by 45% in my tests.
Eliminate an unnecessary variable from vm_map_insert().
Reviewed by: kib
Tested by: pho
that it creates (r267645), we can place the check that blocks map entry
coalescing on stack entries in vm_map_simplify_entry() where it properly
belongs.
Reviewed by: kib
numerical values as MAP_STACK_GROWS_*, but the former is for entries'
eflags, while the later for the cow argument of vm_map_insert().
Submitted by: alc
map entries list, and that it does not overlap with the previous and
next entries.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
corresponding flag(s) in the new map entry. Previously, the caller was
responsible for setting them after vm_map_insert() returned.
Pass MAP_STACK_GROWS_DOWN to vm_map_insert() from vm_map_growstack() when
extending the stack in the downward direction.
Together these changes slightly simplify the caller's task when creating a
downward growing stack. In particular, the caller no longer needs to clip
the previous entry, because the new stack entry can't possibly coalesce
with the previous entry.
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
and prevents the request from deleting existing mappings in the
region, failing instead.
Reviewed by: alc
Discussed with: jhb
Tested by: markj, pho (previous version, as part of the bigger patch)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
the queue where to enqueue pages that are going to be unwired.
- Add stronger checks to the enqueue/dequeue for the pagequeues when
adding and removing pages to them.
Of course, for unmanaged pages the queue parameter of vm_page_unwire() will
be ignored, just as the active parameter today.
This makes adding new pagequeues quicker.
This change effectively modifies the KPI. __FreeBSD_version will be,
however, bumped just when the full cache of free pages will be
evicted.
Sponsored by: EMC / Isilon storage division
Reviewed by: alc
Tested by: pho
would be read once and cached in a local variable so that the resource limit
check and map entry insertion would be guaranteed to use the same value.
However, the value being passed to vm_map_insert() is still from "sgrowsiz"
and not the local variable. Correct this oversight.
Reviewed by: kib
since it will almost certanly fail. Take next bigger zone instead.
This situation should not happen with original bucket zones configuration:
"32 Bucket" zone uses "64 Bucket" and vice versa. But if "64 Bucket" zone
lock is congested, zone may grow its bucket size and start biting itself.
MFC after: 2 weeks
Sponsored by: iXsystems, Inc.
machines. Specifically, there was a mismatch between how the routine
allocation and deallocation operations accessed the population map
and how the aggressively optimized reservation-breaking operation
accessed it. So, problems only occurred when reservations were broken.
This change makes the routine operations access the population map in
the same way as the reservation breaking operation.
This bug was introduced in r259999.
PR: 187080
Tested by: jmg (on an "armeb" machine)
Sponsored by: EMC / Isilon Storage Division
to !MAP_STACK mapping requests. For MAP_STACK | MAP_FIXED, clear any
mappings which could previously exist in the used range.
For this, teach vm_map_find() and vm_map_fixed() to handle
MAP_STACK_GROWS_DOWN or _UP cow flags, by calling a new
vm_map_stack_locked() helper, which is factored out from
vm_map_stack().
The side effect of the change is that MAP_STACK started obeying
MAP_ALIGNMENT and MAP_32BIT flags.
Reported by: rwatson
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
a partially populated reservation becomes fully populated, and decrease this
field when a fully populated reservation becomes partially populated.
Use this field to simplify the implementation of pmap_enter_object() on
amd64, arm, and i386.
On all architectures where we support superpages, the cost of creating a
superpage mapping is roughly the same as creating a base page mapping. For
example, both kinds of mappings entail the creation of a single PTE and PV
entry. With this in mind, use the page size field to make the
implementation of vm_map_pmap_enter(..., MAP_PREFAULT_PARTIAL) a little
smarter. Previously, if MAP_PREFAULT_PARTIAL was specified to
vm_map_pmap_enter(), that function would only map base pages. Now, it will
create up to 96 base page or superpage mappings.
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
situation checked by assert is verified to not take place in
vm_map_wire(), and protection permissions on the wired entry can be
revoked afterward.
Reported by: markj
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
the kmem object lock is held. Do the pmap_remove() before acquiring the
kmem object lock.
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division
on execve(2), it calls vmspace_exec(), which frees the current
vmspace. The thread executing an exec syscall gets new vmspace
assigned, and old vmspace is freed if only referenced by the current
process. The free operation includes pmap_release(), which
de-constructs the paging structures used by hardware.
If the calling process is multithreaded, other threads are suspended
in the thread_suspend_check(), and need to be unsuspended and run to
be able to exit on successfull exec. Now, since the old vmspace is
destroyed, paging structures are invalid, threads are resumed on the
non-existent pmaps (page tables), which leads to triple fault on x86.
To fix, postpone the free of old vmspace until the threads are resumed
and exited. To avoid modifications to all image activators all of
which use exec_new_vmspace(), memoize the current (old) vmspace in
kern_execve(), and notify it about the need to call vmspace_free()
with a thread-private flag TDP_EXECVMSPC.
http://bugs.debian.org/743141
Reported by: Ivo De Decker <ivo.dedecker@ugent.be> through secteam
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
parent and child processes. Previously, we copied these pages even though
they are read only. However, the reason for copying them is historical and
no longer exists. In recent times, vm_map_protect() has developed the
ability to copy pages when write access is added to wired copy-on-write
pages. So, in this case, copy-on-write sharing of wired pages is not to be
feared. It is not going to lead to copy-on-write faults on wired memory.
Reviewed by: kib
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division
avoid soft page faults when adding write access to user wired entries in
vm_map_protect(). Previously, we only avoided the soft page fault when
the underlying pages were copy-on-write. In other words, we avoided the
pages faults that might sleep on page allocation, but not the trivial
page faults to update the physical map.
Reviewed by: kib
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division
need COW and is writeable (i.e. becoming writeable due to the
mprotect(2) operation), do not create a new backing object for the
entry. The caller of the function is vm_map_protect(), the call is
made to ensure that wired entry has all pages resident and wired in
the top level object and to enable the write. We might need to copy
read-only page from some backing objects into the top object or remap
the page with the write allowed.
This fixes the issue with mishandling of the swap accounting when
read-only wired mapping is upgraded to write-enabled after fork. The
previous code path did not accounted the new object, but it creation
is redundand anyway and the change provides an optimization for the
non-common situation.
Reported by: markj
Suggested and reviewed by: alc (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
page queues for the backing objects. The queues are huge and clutter
the display, when mostly the map entries and its backing storage is
interesting.
The page queues can be seen with ddb 'show object' command.
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
allowed range or when one or more pages are not mapped. This according to
The Open Group Base Specifications Issue 7.
Discussed with: attilio, Bruce Evans
Reviewed by: alc, Garrett Cooper
Reported by: ATF
MFC after: 2 weeks
Sponsored by: EMC / Isilon storage division
periodically update the reference status of the active pages. This function
was called, instead of vm_pageout_scan(), when memory was not scarce. The
objective was to provide up to date reference status for active pages in
case memory did become scarce and active pages needed to be deactivated.
The active page queue scan performed by vm_pageout_page_stats() was
virtually identical to that performed by vm_pageout_scan(), and so r254304
eliminated vm_pageout_page_stats(). Instead, vm_pageout_scan() is
called with the parameter "pass" set to zero. The intention was that when
pass is zero, vm_pageout_scan() would only scan the active queue. However,
the variable page_shortage can still be greater than zero when memory is not
scarce and vm_pageout_scan() is called with pass equal to zero.
Consequently, the inactive queue may be scanned and dirty pages laundered
even though that was not intended by r254304. This revision fixes that.
Reported by: avg
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division
into the area backed by vm_page_array wrongly compared end with
vm_page_array_size. It should be adjusted by first_page index to be
correct.
Also, the corner and incorrect case of the requested range extending
after the end of the vm_page_array was incorrectly handled by
allocating the segment.
Fix the comparision for the end of range and return EINVAL if the end
extends beyond vm_page_array.
Discussed with: royger
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
entry and performs the upgrade of the entry permissions from read-only
to read-write, we must allow to search for the source pages in the
backing object, like we do in the case of forking the read-only wired
entry. For the fork case, the behaviour is allowed by src_readonly
boolean, which in fact is only used to assert that read-write case
provides all source pages in the top-level object.
Eliminate the src_readonly variable. Allow for the copy loop to look
into the backing objects, add explicit asserts to ensure that only
read-only and upgrade case actually does.
Expand comments. Change the panic call into assert.
Reported by: markj
Tested by: markj, pho (previous version)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
To reduce the diff struct pcu.cnt field was not renamed, so
PCPU_OP(cnt.field) is still used. pc_cnt and pcpu are also used in
kvm(3) and vmstat(8). The goal was to not affect externally used KPI.
Bump __FreeBSD_version_ in case some out-of-tree module/code relies on the
the global cnt variable.
Exp-run revealed no ports using it directly.
No objection from: arch@
Sponsored by: EMC / Isilon Storage Division
faults.
First, for accesses to direct map region should check for the limit by
which direct map is instantiated.
Second, for accesses to the kernel map, success returned from the
kernacc(9) does not guarantee that consequent attempt to read or write
to the checked address succeed, since other thread might invalidate
the address meantime. Add a new thread private flag TDP_DEVMEMIO,
which instructs vm_fault() to return error when fault happens on the
MAP_ENTRY_NOFAULT entry, instead of panicing. The trap handler would
then see a page fault from access, and recover in normal way, making
/dev/mem access safer.
Remove GIANT_REQUIRED from the amd64 memrw(), since it is not needed
and having Giant locked does not solve issues for amd64.
Note that at least the second issue exists on other architectures, and
requires similar patching for md code.
Reported and tested by: clusteradm (gjb, sbruno)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
then threads can sleep on the pip condition.
Avoid to deadlock such threads by correctly awakening the sleeping ones
after the pip is finished.
swapoff side of the bug can likely result in shutdown deadlocks.
Sponsored by: EMC / Isilon Storage Division
Reported by: pho, pluknet
Tested by: pho
further refinement is required as some device drivers intended to be
portable over FreeBSD versions rely on __FreeBSD_version to decide whether
to include capability.h.
MFC after: 3 weeks
a call of pager_swap_freespace() was moved around, now leading to freeing
the incorrect page because of the pindex changes after vm_page_rename().
Get back to use the correct pindex when destroying the swap space.
Sponsored by: EMC / Isilon storage division
Reported by: avg
Tested by: pho
MFC after: 7 days
map a fraction of the pages that were fetched by vm_pager_get_pages() from
secondary storage. Now, we map them all in order to avoid future soft
faults. This effect is most evident when a memory-mapped file is accessed
sequentially. Previously, there were 6 soft faults for every hard fault.
Now, these soft faults are eliminated.
Sponsored by: EMC / Isilon Storage Division
1. Be consistent in the style of "act_delta" manipulations between the
inactive and active queue scans.
2. Explicitly compare to zero.
3. The deactivation of a page is based is based on its recent history
and not just the current call to vm_pageout_scan(). The variable
"act_delta" represents the current state of the page, and not its
history. Avoid possible confusion by not (ab)using "act_delta" for
the making the deactivation decision.
Submitted by: kib [1]
Reviewed by: kib [2,3]
vm_pageout_scan(). There were missing increments in two less common cases.
Don't conflate the count of stuck pages and the pageout deficit provided by
vm_page_alloc{,_contig}(). (A proposed fix to the OOM code depends on this.)
Handle held pages consistently in the inactive queue scan. In the more
common case, we did not move the page to the tail of the queue. Whereas, in
the less common case, we did. There's no particular reason to move the page
in the less common case, so remove it.
Perform the calculation of the page shortage for the active queue scan a
little earlier, before the active queue lock is acquired. The correctness
of this calculation doesn't depend on the active queue lock being held.
Eliminate a redundant variable, "pcount". Use the more descriptive
variable, "maxscan", in its place.
Apply a few nearby style fixes, e.g., eliminate stray whitespace and excess
parentheses.
Reviewed by: kib
Sponsored by: EMC / Isilon Storage Division
no longer any need for the page's PG_CACHED and PG_FREE flags to be set and
cleared while the free page queues lock is held. Thus, vm_page_alloc(),
vm_page_alloc_contig(), and vm_page_alloc_freelist() can wait until after
the free page queues lock is released to clear the page's flags. Moreover,
the PG_FREE flag can be retired. Now that the reservation system no longer
uses it, its only uses are in a few assertions. Eliminating these
assertions is no real loss. Other assertions catch the same types of
misbehavior, like doubly freeing a page (see r260032) or dirtying a free
page (free pages are invalid and only valid pages can be dirtied).
Eliminate an unneeded variable from vm_page_alloc_contig().
Sponsored by: EMC / Isilon Storage Division
Change the way that reservations keep track of which pages are in use.
Instead of using the page's PG_CACHED and PG_FREE flags, maintain a bit
vector within the reservation. This approach has a couple benefits.
First, it makes breaking reservations much cheaper because there are
fewer cache misses to identify the unused pages. Second, it is a pre-
requisite for supporting two or more reservation sizes.
region is claimed by a new entry.
Pass MAP_STACK_GROWS_DOWN and MAP_STACK_GROWS_UP flags to
vm_map_insert() from vm_map_stack(), to really turn off coalescing
code and call to vm_map_simplify_entry() [1].
Reported by: avg, peter, many
Tested by: avg, peter
Noted by: avg [1]
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
that we don't have a good way (yet) to iterate over the mapped pages by
virtual address and simply try each page within the range. Given that we
call pmap_remove() over the entire 2^63 bytes of address space, it takes
a while for pmap_remove to have tried all 2^50 pages.
By using pmap_remove_pages() we use the PV list to find all mappings.
Change derived from a patch by: alc
argument, cast the incoming 0 argument to void *, to silence a warning
from clang 3.4 ("expression which evaluates to zero treated as a null
pointer constant of type 'void *' [-Wnon-literal-null-conversion]").
MFC after: 3 days
(> PAGE_SIZE) zones. If zone is not multiple to PAGE_SIZE, there may
be enough space for the header at the last page, so we may avoid extra
header memory allocation and hash table update/lookup.
ZFS creates bunch of odd-sized UMA zones (5120, 6144, 7168, 10240, 14336).
This change gives good use to at least some of otherwise lost memory there.
Reviewed by: avg
There are good reasons for this to happen, such as recursion prevention, etc.
and they are not fatal since buckets are just an optimization mechanism.
Real bucket allocation failures are any way counted by the bucket zones
themselves, and we don't need double accounting there.
was used without making sure first that it was really passed for us.
On some of my systems this bug made user argument passed by ZFS code to
uma_zalloc_arg() unexpectedly block UMA per-CPU caches for those zones.
larger than the operational region. If the op region size is zero,
clipping would create a zero-sized map entry. The result is that vm
map splay starts behaving inconsistently, sometimes returning
zero-sized entry, sometimes the next (or previous) entry.
One step further, it could result in e.g. vm_map_wire() setting
MAP_ENTRY_IN_TRANSITION on the zero-sized entry, but failing to clear
it in the done part. The vm_map_delete() than hangs forever waiting
for the flag removal.
Verify for zero-length requests and act as if it is always successfull
without performing any action on the address space.
Diagnosed by: pho
Tested by: pho (previous version)
Reviewed by: alc (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
is chunked to pieces limited by integer io_hold_cnt tunable, while
vm_fault_quick_hold_pages() takes integer max_count as the upper bound.
Rearrange the checks to correctly handle overflowing address arithmetic.
Submitted by: bde
Tested by: pho
Discussed with: alc
MFC after: 1 week
This is a last resort for very low memory condition in case other measures
to free memory were ineffective. Sequentially cycle through all CPUs and
extract per-CPU cache buckets into zone cache from where they can be freed.
Lock congestion is the same, whether it happens on alloc or free, so
handle it equally. Now that we have back pressure, there is no problem
to grow buckets a bit faster. Any way growth is much slower then in 9.x.
These new buckets make bucket size self-tuning more soft and precise.
Without them there are buckets for 1, 5, 13, 29, ... items. While at
bigger sizes difference about 2x is fine, at smallest ones it is 5x and
2.6x respectively. New buckets make that line look like 1, 3, 5, 9, 13,
29, reducing jumps between steps, making algorithm work softer, allocating
and freeing memory in better fitting chunks. Otherwise there is quite a
big gap between allocating 128K and 5x128K of RAM at once.
Every time system detects low memory condition decrease bucket sizes for
each zone by one item. As result, higher memory pressure will push to
smaller bucket sizes and so smaller per-CPU caches and so more efficient
memory use.
Before this change there was no force to oppose buckets growth as result
of practically inevitable zone lock conflicts, and after some run time
per-CPU caches could consume enough RAM to kill the system.
shared vnode lock for VOP_PUTPAGES() as well. The only such
filesystem in the tree is ZFS, and it uses
vnode_pager_generic_putpages(), which performs the pageout with
VOP_WRITE().
Reviewed by: alc
Discussed with: avg
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
coalesce would extend the object to keep pages for the anonymous
mapping created by the process. The pages has no relations to the
tmpfs file content which could be written into the corresponding
range, causing anonymous mapping and file content aliasing and
subsequent corruption.
Another lesser problem created by coalescing is over-accounting on the
tmpfs node destruction, since the object size is substracted from the
total count of the pages owned by the tmpfs mount.
Reported and tested by: bdrewery
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
- add fields to 'struct pmap' that are required to manage nested page tables.
- add a parameter to 'vmspace_alloc()' that can be used to override the
default pmap initialization routine 'pmap_pinit()'.
These changes are pushed ahead of the remaining changes in 'bhyve_npt_pmap'
in anticipation of the upcoming KBI freeze for 10.0.
Reviewed by: kib@, alc@
Approved by: re (glebius)
pmap_clear_reference() has had exactly one caller in the kernel for
several years, more precisely, since FreeBSD 8. Now, that call no
longer exists.
Approved by: re (kib)
Sponsored by: EMC / Isilon Storage Division
exhausted.
- Add a new protect(1) command that can be used to set or revoke protection
from arbitrary processes. Similar to ktrace it can apply a change to all
existing descendants of a process as well as future descendants.
- Add a new procctl(2) system call that provides a generic interface for
control operations on processes (as opposed to the debugger-specific
operations provided by ptrace(2)). procctl(2) uses a combination of
idtype_t and an id to identify the set of processes on which to operate
similar to wait6().
- Add a PROC_SPROTECT control operation to manage the protection status
of a set of processes. MADV_PROTECT still works for backwards
compatability.
- Add a p_flag2 to struct proc (and a corresponding ki_flag2 to kinfo_proc)
the first bit of which is used to track if P_PROTECT should be inherited
by new child processes.
Reviewed by: kib, jilles (earlier version)
Approved by: re (delphij)
MFC after: 1 month
and the equivalent functionality is now provided by sendfile(2) over
posix shared memory filedescriptor.
Remove the cow member of struct vm_page, and rearrange the remaining
members. While there, make hold_count unsigned.
Requested and reviewed by: alc
Tested by: pho
Sponsored by: The FreeBSD Foundation
Approved by: re (delphij)
portion is invalidated, invalidate the whole page. Otherwise,
partially valid page appears on a page queue, which is wrong. This
could only happen for the last page, because only then buffer which
triggered invalidation could not cover the whole page.
Reported and tested by: pho (previous version)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Approved by: re (delphij)
MFC after: 2 weeks
an address in the first 2GB of the process's address space. This flag should
have the same semantics as the same flag on Linux.
To facilitate this, add a new parameter to vm_map_find() that specifies an
optional maximum virtual address. While here, fix several callers of
vm_map_find() to use a VMFS_* constant for the findspace argument instead of
TRUE and FALSE.
Reviewed by: alc
Approved by: re (kib)
pmap_remove_all(). Not doing the drain allows the pmap_enter() to
proceed in parallel, making the pmap_remove_all() effects void.
The race results in an invalidated page mapped wired by usermode.
Reported and tested by: pho
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Approved by: re (glebius)
VPB_BIT_WAITERS flag were changed between reading of busy_lock and the
cas. The vm_page_sbusy(), which is the only user of
vm_page_trysbusy() in the tree, panics on the failure, which in these
cases is transient and do not mean that the current page state
prevents sbusying.
Retry the operation inside vm_page_trysbusy() if cas failed, only
return a failure when VPB_BIT_SHARED is cleared.
Reported and tested by: pho
Reviewed by: attilio
Sponsored by: The FreeBSD Foundation
in the future in a backward compatible (API and ABI) way.
The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.
The structure definition looks like this:
struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};
The initial CAP_RIGHTS_VERSION is 0.
The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.
The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.
To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.
#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)
We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:
#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)
#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)
There is new API to manage the new cap_rights_t structure:
cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);
bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);
Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:
cap_rights_t rights;
cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);
There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:
#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);
Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:
cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);
Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.
This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.
Sponsored by: The FreeBSD Foundation
The consequence of the bug is that fini calls are not done
when a slab is freed by a call-back from the page daemon.
It went unnoticed for two months because fini is little used.
I spotted the bug while reading the code to learn how it works
so I could write it up for the next edition of the Design and
Implementation of FreeBSD book.
No MFC needed as this code exists only in HEAD.
Reviewed by: kib, jeff
Tested by: pho
MADV_DONTNEED) and madvise(..., MADV_FREE). Specifically, introduce a new
pmap function, pmap_advise(), that operates on a range of virtual addresses
within the specified pmap, allowing for a more efficient implementation of
MADV_DONTNEED and MADV_FREE. Previously, the implementation of
MADV_DONTNEED and MADV_FREE relied on per-page pmap operations, such as
pmap_clear_reference(). Intuitively, the problem with this implementation
is that the pmap-level locks are acquired and released and the page table
traversed repeatedly, once for each resident page in the range
that was specified to madvise(2). A more subtle flaw with the previous
implementation is that pmap_clear_reference() would clear the reference bit
on all mappings to the specified page, not just the mapping in the range
specified to madvise(2).
Since our malloc(3) makes heavy use of madvise(2), this change can have a
measureable impact. For example, the system time for completing a parallel
"buildworld" on a 6-core amd64 machine was reduced by about 1.5% to 2.0%.
Note: This change only contains pmap_advise() implementations for a subset
of our supported architectures. I will commit implementations for the
remaining architectures after further testing. For now, a stub function is
sufficient because of the advisory nature of pmap_advise().
Discussed with: jeff, jhb, kib
Tested by: pho (i386), marcel (ia64)
Sponsored by: EMC / Isilon Storage Division
reclaim the last preexisting cached page in the object, resulting in a call
to vdrop(). Detect this scenario so that the vnode's hold count is
correctly maintained. Otherwise, we panic.
Reported by: scottl
Tested by: pho
Discussed with: attilio, jeff, kib
which is the part of struct vmspace, allocated from UMA_ZONE_NOFREE
zone. Initialize the pmap lock in the vmspace zone init function, and
remove pmap lock initialization and destruction from pmap_pinit() and
pmap_release().
Suggested and reviewed by: alc (previous version)
Tested by: pho
Sponsored by: The FreeBSD Foundation
The flag was mandatory since r209792, where vm_page_grab(9) was
changed to only support the alloc retry semantic.
Suggested and reviewed by: alc
Sponsored by: The FreeBSD Foundation
necessary since we do not free or cache the page from active anymore.
Document the one possible race that is harmless.
Sponsored by: EMC / Isilon Storage Division
Discussed with: alc
shown to negatively impact some workloads and the goal is only to
eliminate worst case behaviors for very long periods of paging
inactivity. Eventually we should determine a more complex scaling
factor for this feature.
- Rate limit low memory callback handlers to limit thrashing. Set the
default to 10 seconds.
Sponsored by: EMC / Isilon Storage Division
