The memory-mapped files implementation (mmap() etc.) is implemented with
the help of the filesystems using the in-VM FS cache. Filesystems tell it
about all cached blocks and their metadata. Metadata is: device offset and,
if any (and known), inode number and in-inode offset. VM can then map in
requested memory-mapped file blocks, and request them if necessary.
A limitation of this system is that filesystem block sizes that are not
a multiple of the VM system (and VM hardware) page size are not possible;
we can't map blocks in partially. (We can copy, but then the benefits of
mapping and sharing the physical pages is gone.) So until before this
commit various pieces of caching code assumed page size multiple
blocksizes. This isn't strictly necessary as long as mmap() needn't be
supported on that FS.
This change allows the in-FS cache code (libminixfs) to allocate any-sized
blocks, and will not interact with the VM cache for non-pagesize-multiple
blocks. In that case it will also signal requestors, by failing 'peek'
requests, that mmap() should not be supported on this FS. VM and VFS
will then gracefully fail all file-mapping mmap() calls, and exec() will
fall back to copying executable blocks instead of mmap()ping executables.
As a result, 3 diagnostics that signal file-mapped mmap()s failing
(hitherto an unusual occurence) are disabled, as ld.so does file-mapped
mmap()s to map in objects it needs. On FSes not supporting it this situation
is legitimate and shouldn't cause so much noise. ld.so will revert to its own
minix-specific allocate+copy style of starting executables if mmap()s fail.
Change-Id: Iecb1c8090f5e0be28da8f5181bb35084eb18f67b
When we start using a new pagetable (for a new process)
the last part is to ensure the pagetable itself can be
accessed by VM. This is done in pt_bind by updating
the "pagetable of pagetables" and we want this mapping
to match other mappings to the l1 pagetable.
Change-Id: I7b506fd75553917fdc1abd25b55e4b2f25ccbf8d
. turns on mmap() functionality for files by default
. also causes exec() to use it to map in executables
without copying and with sharing those pages with the
disk cache and other instances of the executable
Change-Id: Idb94dfe110eed916cf83b12c45e1a77241a2cee5
The VM server now manages its call masks such that all user processes
share the same call mask. As a result, an update for the call mask of
any user process will apply to all user processes. This is similar to
the privilege infrastructure employed by the kernel, and may serve as
a template for similar fine-grained restrictions in other servers.
Concretely, this patch fixes the problem of "service edit init" not
applying the given VM call mask to user processes started from RC
scripts during system startup.
In addition, this patch makes RS set a proper VM call mask for each
recovery script it spawns.
Change-Id: I520a30d85a0d3f3502d2b158293a2258825358cf
Implement getrusage.
These fields of struct rusage are not supported and always set to zero at this time
long ru_nswap; /* swaps */
long ru_inblock; /* block input operations */
long ru_oublock; /* block output operations */
long ru_msgsnd; /* messages sent */
long ru_msgrcv; /* messages received */
long ru_nvcsw; /* voluntary context switches */
long ru_nivcsw; /* involuntary context switches */
test75.c is the unit test for this new function
Change-Id: I3f1eb69de1fce90d087d76773b09021fc6106539
. test74 for mmap functionality
. vm: add a mem_file memory type that specifies an mmap()ped
memory range, backed by a file
. add fdref, an object that keeps track of FD references within
VM per process and so knows how to de-duplicate the use of FD's
by various mmap()ped ranges; there can be many more than there can
be FD's
. turned off for now, enable with 'filemap=1' as boot option
Change-Id: I640b1126cdaa522a0560301cf6732b7661555672
The natural term to use when talking about MINIX big pages on ARM
is SECTION. A section is a level 1 page table entry pointing to
a 1MB area.
Change-Id: I9bd27ca99bc772126c31c27a537b1415db20c4a6
In libexec, split the memory allocation method into cleared and
non-cleared. Cleared gives zeroed memory, non-cleared gives 'junk'
memory (that will be overwritten anyway, and so needn't be cleared)
that is faster to get.
Also introduce the 'memmap' method that can be used, if available,
to map code and data from executables into a process using the
third-party mmap() mode.
Change-Id: I26694fd3c21deb8b97e01ed675dfc14719b0672b
Primary purpose of change: to support the mmap implementation, VM must
know both (a) about some block metadata for FS cache blocks, i.e.
inode numbers and inode offsets where applicable; and (b) know about
*all* cache blocks, i.e. also of the FS primary caches and not just
the blocks that spill into the secondary one. This changes the
interface and VM data structures.
This change is only for the interface (libminixfs) and VM data
structures; the filesystem code is unmodified, so although the
secondary cache will be used as normal, blocks will not be annotated
with inode information until the FS is modified to provide this
information. Until it is modified, mmap of files will fail gracefully
on such filesystems.
This is indicated to VFS/VM by returning ENOSYS for REQ_PEEK.
Change-Id: I1d2df6c485e6c5e89eb28d9055076cc02629594e
Memory types in VM are described by methods. Each mapped region has
a type, and all pages instantiated get that type on creation.
Individual page types has to be able to change though. This commit
changes the code to use the memory types of the individual pages,
where appropriate, instead of just the higher-level region, in case
it has changed. This is needed to e.g. support future copy-on-write
MAP_PRIVATE mmap modes.
Change-Id: I5523db14ac036ec774a54392fb67f9acb8725731
Some (backwards-compatible) changes in mmap() call message fields
that allow for a 64-bit offset. minix_mmap() takes an off_t and
minix_mmap64() takes a u64_t. Some mmap() work in VM goes into a
separate function, using the new fields, so that that can be re-used
when files are to be mapped (future commit).
Change-Id: Ifb77a90b593dd3c33cf81b396068e4da1ec5fb1c
This commit removes the secondary cache code implementation from
VM and its usage from libminixfs. It is to be replaced by a new
implementation.
Change-Id: I8fa3af06330e7604c7e0dd4cbe39d3ce353a05b1
. test70: regression test for m_out vfs race condition
The following tests use testcache.c to generate test i/o
patterns, generate random write data and verify the reads.
. test71: blackbox full-stack test of FS operation, testing
using the regular VFS interface crazy i/o patterns
with various working set sizes, triggering only
primary cache, also secondary cache, and finally
disk i/o and verifying contents all the time
. test72: unit test of libminixfs, implementing
functions it needs from -lsys and -lblockdriver
and the client in order to simulate a working
cache client and backend environment.
. test73: blackbox test of secondary vm cache in isolation
Change-Id: I1287e9753182b8719e634917ad158e3c1e079ceb
In order to make it more clear that ticks should be used for timers
and realtime should be used for timestamps / displaying the date/time,
getuptime() was renamed to getticks() and getuptime2() was renamed to
getuptime().
Servers, drivers, libraries, tests, etc that use getuptime()/getuptime2()
have been updated. In instances where a realtime was calculated, the
calculation was changed to use realtime.
System calls clock_getres() and clock_gettime() were added to PM/libc.
. data structure that automatically keeps a set
of pages in reserve, to replace sparepages and
possibly re-used in the future for similar situations,
e.g. if in-filesystem-cache block eviction is
implemented and FS asks for a new block
Change-Id: I149d46c14b9c8e75df16cb94e08907f008c339a6
. if there is no memory there, it's not writable; this
check bug by the shared memory's writable() method causes
pagefaults not to be handled at all in certain situations,
triggering an assert() in pt_writemap()
. added some assert()s to catch this and similar situations
in the future
Change-Id: Ife89bfab4f9a3aa7bf4e33dfb0b13b89dcd5bb94
The build system distinction between "bootprog" and "service" is
meaningless as boot programs are standard services.
As minix.service.mk simply imports minix.bootprog.mk, reduce confusion
by removing minix.bootprog.mk and placing the rules in minix.service.mk.
Change-Id: I4056b1e574bed59a8c890239b41b1a7c7cad63e8
. the total amount of memory in the system didn't include the memory
used by the boot-time modules and some dynamic allocation by the
kernel at boot time (to map in VM). especially apparent on our
ARM board with 'only' 512MB of memory and a huge ramdisk.
. also: *add* the VM loaded module to the freelist after it has
been allocated for & mapped in instead of cutting it *out* of the
freelist! so we get a few more MB free..
Change-Id: If37ac32b21c9d38610830e21421264da4f20bc4f
. allow any number of pde's used for pagedir mapping
. allows >1024 NR_PROCS on x86, >64 on ARM
. allows NR_PROCS to be the same in both cases
. also cleanup: allocating spare PDE's is not necessary
throw that function out
Change-Id: Ibb8f8cf6e7db6a4d6384b6911d1a3f3f5e5d8256
if an exec() fails partway through reading in the sections, the target
process is already gone and a defunct process remains. sanity checking
the binary beforehand helps that.
test10 mutilates binaries and exec()s them on purpose; making an exec()
fail cleanly in such cases seems like acceptable behaviour.
fixes test10 on ARM.
Change-Id: I1ed9bb200ce469d4d349073cadccad5503b2fcb0
The 'polarity' of the RW bit is inversed on ARM, causing one
of the sanity check compensations to fail. ARM now runs basic
stuff with sanity checks passing.
Change-Id: Iee28ab63e430e759f204eeb204b24c301d5ea3c9
. make vm tell kernel virtual locations of mappings
. makes _minix_kerninfo feature work
. fix for mappings being larger than what 1 pde can address
(e.g. devices memory requested on arm)
. still requires a special case for devices memory for the
kernel, which has to switch to virtual addressing
Change-Id: I2e94090aa432346fa4da0edeba72f0b7406c2ad7
Due to the ABI we are using we have to use the earm architecture
moniker for the build system to behave correctly. This involves
then some headers to move around.
There is also a few related Makefile updates as well as minor
source code corrections.
Fix warnings about:
. Unused variables
. format mismatch in printf/scanf format string and arguments
. Missing parenthesis around assignment as truth values
. Clang warnings anout unknown GCC pragma
