diff options
author | Andreas Sandberg <andreas@sandberg.pp.se> | 2015-11-26 10:11:52 +0000 |
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committer | Andreas Sandberg <andreas@sandberg.pp.se> | 2015-11-26 10:11:52 +0000 |
commit | 6de52699bb10ec445e45400b419bb61122a68162 (patch) | |
tree | 5b9fef2a697556e4b9cca062bcd50fa5c0f440aa /src/dev/storage/disk_image.cc | |
parent | 738d71f6a93e2da9ef5bb1490f2b94f9541735e3 (diff) | |
download | gem5-6de52699bb10ec445e45400b419bb61122a68162.tar.xz |
dev: Add post-fork handling for disk images
This changeset adds support for notifying the disk images that the simulator has
been forked. We need to disable the saving of the CoW disk image from the child
process, and we need to make sure that systems which use a raw disk image are
not allowed to fork to avoid two or more gem5 processes writing to the same disk
image.
Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Diffstat (limited to 'src/dev/storage/disk_image.cc')
-rw-r--r-- | src/dev/storage/disk_image.cc | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/src/dev/storage/disk_image.cc b/src/dev/storage/disk_image.cc index 24688f55a..e7fda40a2 100644 --- a/src/dev/storage/disk_image.cc +++ b/src/dev/storage/disk_image.cc @@ -65,6 +65,17 @@ RawDiskImage::~RawDiskImage() { close(); } void +RawDiskImage::notifyFork() +{ + if (initialized && !readonly) + panic("Attempting to fork system with read-write raw disk image."); + + const Params *p(dynamic_cast<const Params *>(params())); + close(); + open(p->image_file, p->read_only); +} + +void RawDiskImage::open(const string &filename, bool rd_only) { if (!filename.empty()) { @@ -198,6 +209,16 @@ CowDiskImage::~CowDiskImage() } void +CowDiskImage::notifyFork() +{ + if (!dynamic_cast<const Params *>(params())->read_only && + !filename.empty()) { + inform("Disabling saving of COW image in forked child process.\n"); + filename = ""; + } +} + +void SafeRead(ifstream &stream, void *data, int count) { stream.read((char *)data, count); @@ -311,8 +332,12 @@ SafeWriteSwap(ofstream &stream, const T &data) void CowDiskImage::save() const { - save(filename); -} + // filename will be set to the empty string to disable saving of + // the COW image in a forked child process. Save will still be + // called because there is no easy way to unregister the exit + // callback. + if (!filename.empty()) + save(filename);} void CowDiskImage::save(const string &file) const |