RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 23:28:11 +00:00
Code Issues Activity Actions

Kernel: Memory purging improvements

Browse source 
This adds the ability for a Region to define volatile/nonvolatile
areas within mapped memory using madvise(). This also means that
memory purging takes into account all views of the PurgeableVMObject
and only purges memory that is not needed by all of them. When calling
madvise() to change an area to nonvolatile memory, return whether
memory from that area was purged. At that time also try to remap
all memory that is requested to be nonvolatile, and if insufficient
pages are available notify the caller of that fact.
This commit is contained in:
Tom 2020-09-02 22:57:09 -06:00 • committed by Andreas Kling
parent cf2c215def
commit bc5d6992a4
14 changed files with 655 additions and 62 deletions
Download patch file Download diff file Expand all files Collapse all files

33
Kernel/Syscalls/mmap.cpp
View file

@ -282,31 +282,30 @@ int Process::sys$madvise(void* address, size_t size, int advice)
return -EINVAL;
if (!region->is_mmap())
return -EPERM;
if ((advice & MADV_SET_VOLATILE) && (advice & MADV_SET_NONVOLATILE))
bool set_volatile = advice & MADV_SET_VOLATILE;
bool set_nonvolatile = advice & MADV_SET_NONVOLATILE;
if (set_volatile && set_nonvolatile)
return -EINVAL;
if (advice & MADV_SET_VOLATILE) {
if (set_volatile || set_nonvolatile) {
if (!region->vmobject().is_purgeable())
return -EPERM;
auto& vmobject = static_cast<PurgeableVMObject&>(region->vmobject());
vmobject.set_volatile(true);
bool was_purged = false;
switch (region->set_volatile(VirtualAddress(address), size, set_volatile, was_purged)) {
case Region::SetVolatileError::Success:
break;
case Region::SetVolatileError::NotPurgeable:
return -EPERM;
case Region::SetVolatileError::OutOfMemory:
return -ENOMEM;
}
if (set_nonvolatile)
return was_purged ? 1 : 0;
return 0;
}
if (advice & MADV_SET_NONVOLATILE) {
if (!region->vmobject().is_purgeable())
return -EPERM;
auto& vmobject = static_cast<PurgeableVMObject&>(region->vmobject());
if (!vmobject.is_volatile())
return 0;
vmobject.set_volatile(false);
bool was_purged = vmobject.was_purged();
vmobject.set_was_purged(false);
return was_purged ? 1 : 0;
}
if (advice & MADV_GET_VOLATILE) {
if (!region->vmobject().is_purgeable())
return -EPERM;
auto& vmobject = static_cast<PurgeableVMObject&>(region->vmobject());
return vmobject.is_volatile() ? 0 : 1;
return region->is_volatile(VirtualAddress(address), size) ? 0 : 1;
}
return -EINVAL;
}