- 07 May, 2007 40 commits
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Jeff Dike authored
Instead of writing entire structures between UML and the I/O thread, we send pointers. This cuts down on the amount of data being copied and possibly allows more requests to be pending between the two. This requires that the requests be kmalloced and freed instead of living on the stack. Signed-off-by:
Jeff Dike <jdike@linux.intel.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Jeff Dike authored
Send as many I/O requests to the I/O thread as possible, even though it will still only handle one at a time. This provides an opportunity to reduce latency by starting one request before the previous one has been finished in the driver. Request handling is somewhat modernized by requesting sg pieces of a request and handling them separately, finishing off the entire request after all the pieces are done. When a request queue stalls, normally because its pipe to the I/O thread is full, it is put on the restart list. This list is processed by starting up the queues on it whenever there is some indication that progress might be possible again. Currently, this happens in the driver interrupt routine. Some requests have been finished, so there is likely to be room in the pipe again. This almost doubles throughput when copying data between devices, but made no noticable difference on anything else I tried. Signed-off-by:
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Jeff Dike authored
This patch converts calls in the os layer to os_{read,write}_file to calls directly to libc read() and write() where it is clear that the I/O buffer is in the kernel. We can do that here instead of calling os_{read,write}_file_k since we are in libc code and can call libc directly. With the change in the calls, error handling needs to be changed to refer to errno directly rather than the return value of the call. CATCH_EINTR wrappers were also added where needed. Signed-off-by: -
Jeff Dike authored
This patch lays some groundwork for the next one, which converts calls to os_{read,write}_file into {read,write}, by doing some tidying in the affected areas. do_not_aio gets restructured to make the final result a bit cleaner. There are also whitespace and other formatting fixes, fixes in error messages, and a typo fix. Signed-off-by: -
Jeff Dike authored
This patch starts the removal of a very old, very broken piece of code. This stems from the problem of passing a userspace buffer into read() or write() on the host. If that buffer had not yet been faulted in, read and write will return -EFAULT. To avoid this problem, the solution was to fault the buffer in before the system call by touching the pages that hold the buffer by doing a copy-user of a byte to each page. This is obviously bogus, but it does usually work, in tt mode, since the kernel and process are in the same address space and userspace addresses can be accessed directly in the kernel. In skas mode, where the kernel and process are in separate address spaces, it is completely bogus because the userspace address, which is invalid in the kernel, is passed into the system call instead of the corresponding physical address, which would be valid. Here, it appears that this code, on every host read() or write(), tries to fault in a random process page. This doesn't seem to cause any correctness problems, but there is a performance impact. This patch, and the ones following, result in a 10-15% performance gain on a kernel build. This code can't be immediately tossed out because when it is, you can't log in. Apparently, there is some code in the console driver which depends on this somehow. However, we can start removing it by switching the code which does I/O using kernel addresses to using plain read() and write(). This patch introduces os_read_file_k and os_write_file_k for use with kernel buffers and converts all call locations which use obvious kernel buffers to use them. These include I/O using buffers which are local variables which are on the stack or kmalloc-ed. Later patches will handle the less obvious cases, followed by a mass conversion back to the original interface. Signed-off-by:
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Jeff Dike authored
It turns out that essentially none of the x86_64 bugs.c is needed. So, we can delete most of it. Signed-off-by:
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Jeff Dike authored
The previous page table walking code was horribly inefficient. This patch replaces it with code taken from elsewhere in the kernel. Forking from bash is now ~5% faster and page faults are handled ~10% faster. Signed-off-by:
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Jeff Dike authored
Provide a register dump if handle_trap fails. Abstract out ptrace_dump_regs since it now has two callers. Signed-off-by:
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Jeff Dike authored
Define release methods for the ubd and net drivers. They contain as much of the remove methods as make sense. All error checking must have already been done as well as anything else that might be holding a reference on the device kobject. Signed-off-by:
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Jeff Dike authored
HOST_FRAME_SIZE isn't used any more. It has been replaced with MAX_REG_NR. Signed-off-by:
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Jeff Dike authored
Locking commentary. Signed-off-by:
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Jeff Dike authored
Commentary about missing locking. Also got rid of uml_start because it was pointless. Signed-off-by:
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Jeff Dike authored
If there's a segfault inside the kernel, we want a dump of the registers at the point of the segfault, not the registers at the point of calling panic or the last userspace registers. sig_handler_common_skas now uses a static register set in the case of a SIGSEGV to avoid messing up the process registers if the segfault turns out to be non-fatal. The architecture sigcontext-to-pt_regs copying code was repurposed to copy data out of the SEGV stack frame. Signed-off-by:
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Jeff Dike authored
Tidying in preparation for the segfault register dumping patch which follows. void * pointers are changed to union uml_pt_regs *. This makes the types match reality, except in arch_fixup, which is changed to operate on a union uml_pt_regs. This fixes a bug in the call from segv_handler, which passes a union uml_pt_regs, to segv, which expects to pass a struct sigcontext to arch_fixup. Whitespace and other style fixes. There's also a errno printk fix. Signed-off-by:
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Jeff Dike authored
kernel_thread() should just return an error value on do_fork failure, not panic. Signed-off-by:
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Jeff Dike authored
userspace code used to have to call the kernelspace function page_size() in order to determine the value of the kernel's PAGE_SIZE. Since this is now available directly from kern_constants.h as UM_KERN_PAGE_SIZE, page_size() can be deleted and calls changed to use the constant. Signed-off-by:
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Jeff Dike authored
Clean up arch/um/kernel/process.c: - lots of return(x); -> return x; conversions - a number of the small functions are either unused, in which case they are gone, along any declarations in a header, or could be made static. - current_pid is ifdefed on CONFIG_MODE_TT and its declaration is ifdefed on both CONFIG_MODE_TT and UML_CONFIG_MODE_TT because we don't know whether it's being used in a userspace or kernel file. Signed-off-by:
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Jeff Dike authored
Comment the lack of locking on a couple of globals. Also fix the formatting of __setup_host_supports_tls. Signed-off-by:
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Jeff Dike authored
flush_thread doesn't need to do a full page table walk in order to clear the address space. It knows what the end result needs to be, so it can call unmap directly. This results in a 10-20% speedup in an exec from bash. Signed-off-by:
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Davide Brini authored
Calls lines_init() *after* xterm_title is modified to include umid. Signed-off-by:
Davide Brini <davide.brini@unibo.it> Signed-off-by:
Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
To look at users I did: $ find arch/um/ include/asm-um -name '*.[ch]'|xargs grep -r 'net_kern\.h' +-l|xargs grep '\<user\>' Most users just cast user to the appropriate pointer, the remaining ones are fixed here. In net_kern.c, I'm almost sure that save trick is not needed anymore, but I've not verified it. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
Avoid using the temporary buffer introduced by previous patch to hold the device name. Btw, avoid leaking device on an error path. Other error paths may need cleanup. Signed-off-by:
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Paolo 'Blaisorblade' Giarrusso authored
Improve checking and diagnostics for broadcast and multicast Ethernet MAC addresses, and distinguish between those cases in output; also make sure the device is assigned a MAC address valid only locally to avoid collisions. Signed-off-by:
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Robert P. J. Day authored
Signed-off-by:
Robert P. J. Day <rpjday@mindspring.com> Acked-by:
Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
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Jeff Dike authored
The build started finding calls from non-init to init functions. These are just cases of init functions not being properly marked, so this patch fixes that. Signed-off-by:
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Jeff Dike authored
user_util.h isn't needed any more, so delete it and remove all includes of it. Signed-off-by:
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Jeff Dike authored
Rescue the useful contents of the soon-to-be-gone user-util.h. pty.c now gets ptsname from stdlib.h like it should have always done. CATCH_EINTR is now in os.h, although perhaps all usage should be under os-Linux at some point. get_pty is also in os.h. This patch restores the old definition of ARRAY_SIZE in user.h. This file is included only in userspace files, so there will be no conflict with the kernel's new ARRAY_SIZE. The copy of the kernel's ARRAY_SIZE and associated infrastructure is now gone. Signed-off-by:
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Jeff Dike authored
This patch moves all the the symbols defined in um_arch.c, which are mostly boundaries between different parts of the UML kernel address space, to a new header, as-layout.h. There are also a few things here which aren't really related to address space layout, but which don't really have a better place to go. Signed-off-by:
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Jeff Dike authored
This patch moves the declarations of the architecture hooks from user_util.h to a new header, arch.c, and adds the necessary includes to files which need those declarations. Signed-off-by:
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Jeff Dike authored
This patch narrows the sigio interface. The boot-time SIGIO testing used to be in start_up.c, which meant that pty_output_sigio and pty_close_sigio needed to be global. By moving that code here, those can become static and the declarations moved from user_util.h. os_check_bugs is also here because it only does the SIGIO checking. If it does more, it'll probably move back to start_up.c. Signed-off-by:
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Rusty Russell authored
We can use a gcc extension to ensure that ARRAY_SIZE() is handed an array, not a pointer. This is especially important when code is changed from a fixed array to a pointer. I assume the Intel compiler doesn't support __builtin_types_compatible_p. [jdike@addtoit.com: uml: update UML definition of ARRAY_SIZE] Signed-off-by:
Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Jeff Dike authored
This fixes a number of problems associated with network interface hotplug. The userspace initialization function can fail in some cases, but the failure was never passed back to eth_configure, which proceeded with the configuration. This results in a zombie device that is present, but can't work. This is fixed by allowing the initialization routines to return an error, which is checked, and the configuration aborted on failure. eth_configure failed to check for many failures. Even when it did check, it didn't undo whatever initializations has already happened, so a present, but partially initialized and non-working device could result. It now checks everything that can fail, and bails out, undoing whatever had been done. The return value of eth_configure was always ignored, so it is now just void. Signed-off-by:
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Andrew Morton authored
Cc: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by:
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Jeff Dike authored
Fix a bunch of formatting violations in the drivers: return(n) -> return n whitespace fixes emacs formatting comment removal breaking if(foo) return(n) into two lines There are also a couple of errno use bugs: using errno in a printk when the failure put errno into a local variable saving errno after a printk, which can change it Signed-off-by:
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Jeff Dike authored
If a disk fails to open, i.e. its host file doesn't exist, it won't be removable because the hot-unplug code checks the existence of its gendisk. This won't exist because it is only allocated for successfully opened disks. Thus, a typo on the command line can result in a unusable and unfixable disk. This is fixed by freeing the gendisk if it's there, but not letting that affect the removal. Signed-off-by:
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Jeff Dike authored
Print out core dump limits at boot time. This is to allow core dumps to be collected if something goes very wrong and to tell if a core dump isn't going to happen because of a resource limit. Signed-off-by:
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Jeff Dike authored
Mark some tt-mode-only code as such. Also cleaned up some formatting. Signed-off-by:
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Jeff Dike authored
Move the host_info string from util.c to um_arch.c, where it is actually initialized and used. Also document its lack of locking. Signed-off-by:
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Jeff Dike authored
Formatting fixes - style violations whitespace breakage emacs formatting comment removal Signed-off-by:
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Jeff Dike authored
Get rid of a bunch of unused stuff - cpu_feature had no users linux_prog is little-used, so its declaration is moved to the user for easy deletion when the whole file goes away a long-unused debugging aid in helper.c is gone Signed-off-by:
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