- 14 8月, 2008 3 次提交
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由 Alan Stern 提交于
This patch (as1121) fixes a bug in the USB serial core. When a device is unregistered, the core will give back its minors -- even if the device hasn't been assigned any! The patch reserves the highest minor value (255) to mean that no minor was assigned. It also removes some dead code and does a small style fixup. Signed-off-by: NAlan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
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由 Alan Stern 提交于
This patch (as1117) adds a kerneldoc line for the "needs_binding" field in struct usb_interface. It was accidentally omitted when the field was added. Signed-off-by: NAlan Stern <stern@rowland.harvard.edu> Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
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由 Linus Torvalds 提交于
Done as a script (well, a single "git mv" actually) on request from Yoshinori Sato as a way to avoid a huge diff. Requested-by: NYoshinori Sato <ysato@users.sourceforge.jp> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 8月, 2008 13 次提交
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由 Suresh Siddha 提交于
Wolfgang Walter reported this oops on his via C3 using padlock for AES-encryption: ################################################################## BUG: unable to handle kernel NULL pointer dereference at 000001f0 IP: [<c01028c5>] __switch_to+0x30/0x117 *pde = 00000000 Oops: 0002 [#1] PREEMPT Modules linked in: Pid: 2071, comm: sleep Not tainted (2.6.26 #11) EIP: 0060:[<c01028c5>] EFLAGS: 00010002 CPU: 0 EIP is at __switch_to+0x30/0x117 EAX: 00000000 EBX: c0493300 ECX: dc48dd00 EDX: c0493300 ESI: dc48dd00 EDI: c0493530 EBP: c04cff8c ESP: c04cff7c DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 Process sleep (pid: 2071, ti=c04ce000 task=dc48dd00 task.ti=d2fe6000) Stack: dc48df30 c0493300 00000000 00000000 d2fe7f44 c03b5b43 c04cffc8 00000046 c0131856 0000005a dc472d3c c0493300 c0493470 d983ae00 00002696 00000000 c0239f54 00000000 c04c4000 c04cffd8 c01025fe c04f3740 00049800 c04cffe0 Call Trace: [<c03b5b43>] ? schedule+0x285/0x2ff [<c0131856>] ? pm_qos_requirement+0x3c/0x53 [<c0239f54>] ? acpi_processor_idle+0x0/0x434 [<c01025fe>] ? cpu_idle+0x73/0x7f [<c03a4dcd>] ? rest_init+0x61/0x63 ======================= Wolfgang also found out that adding kernel_fpu_begin() and kernel_fpu_end() around the padlock instructions fix the oops. Suresh wrote: These padlock instructions though don't use/touch SSE registers, but it behaves similar to other SSE instructions. For example, it might cause DNA faults when cr0.ts is set. While this is a spurious DNA trap, it might cause oops with the recent fpu code changes. This is the code sequence that is probably causing this problem: a) new app is getting exec'd and it is somewhere in between start_thread() and flush_old_exec() in the load_xyz_binary() b) At pont "a", task's fpu state (like TS_USEDFPU, used_math() etc) is cleared. c) Now we get an interrupt/softirq which starts using these encrypt/decrypt routines in the network stack. This generates a math fault (as cr0.ts is '1') which sets TS_USEDFPU and restores the math that is in the task's xstate. d) Return to exec code path, which does start_thread() which does free_thread_xstate() and sets xstate pointer to NULL while the TS_USEDFPU is still set. e) At the next context switch from the new exec'd task to another task, we have a scenarios where TS_USEDFPU is set but xstate pointer is null. This can cause an oops during unlazy_fpu() in __switch_to() Now: 1) This should happen with or with out pre-emption. Viro also encountered similar problem with out CONFIG_PREEMPT. 2) kernel_fpu_begin() and kernel_fpu_end() will fix this problem, because kernel_fpu_begin() will manually do a clts() and won't run in to the situation of setting TS_USEDFPU in step "c" above. 3) This was working before the fpu changes, because its a spurious math fault which doesn't corrupt any fpu/sse registers and the task's math state was always in an allocated state. With out the recent lazy fpu allocation changes, while we don't see oops, there is a possible race still present in older kernels(for example, while kernel is using kernel_fpu_begin() in some optimized clear/copy page and an interrupt/softirq happens which uses these padlock instructions generating DNA fault). This is the failing scenario that existed even before the lazy fpu allocation changes: 0. CPU's TS flag is set 1. kernel using FPU in some optimized copy routine and while doing kernel_fpu_begin() takes an interrupt just before doing clts() 2. Takes an interrupt and ipsec uses padlock instruction. And we take a DNA fault as TS flag is still set. 3. We handle the DNA fault and set TS_USEDFPU and clear cr0.ts 4. We complete the padlock routine 5. Go back to step-1, which resumes clts() in kernel_fpu_begin(), finishes the optimized copy routine and does kernel_fpu_end(). At this point, we have cr0.ts again set to '1' but the task's TS_USEFPU is stilll set and not cleared. 6. Now kernel resumes its user operation. And at the next context switch, kernel sees it has do a FP save as TS_USEDFPU is still set and then will do a unlazy_fpu() in __switch_to(). unlazy_fpu() will take a DNA fault, as cr0.ts is '1' and now, because we are in __switch_to(), math_state_restore() will get confused and will restore the next task's FP state and will save it in prev tasks's FP state. Remember, in __switch_to() we are already on the stack of the next task but take a DNA fault for the prev task. This causes the fpu leakage. Fix the padlock instruction usage by calling them inside the context of new routines irq_ts_save/restore(), which clear/restore cr0.ts manually in the interrupt context. This will not generate spurious DNA in the context of the interrupt which will fix the oops encountered and the possible FPU leakage issue. Reported-and-bisected-by: NWolfgang Walter <wolfgang.walter@stwm.de> Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 Herbert Xu 提交于
The top-level functions init/update/final were missing for ahash. Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
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由 David Chinner 提交于
XFS object flushing doesn't quite match existing completion semantics. It mixed exclusive access with completion. That is, we need to mark an object as being flushed before flushing it to disk, and then block any other attempt to flush it until the completion occurs. We do this but adding an extra count to the completion before we start using them. However, we still need to determine if there is a completion in progress, and allow no-blocking attempts fo completions to decrement the count. To do this we introduce: int try_wait_for_completion(struct completion *x) returns a failure status if done == 0, otherwise decrements done to zero and returns a "started" status. This is provided to allow counted completions to begin safely while holding object locks in inverted order. int completion_done(struct completion *x) returns 1 if there is no waiter, 0 if there is a waiter (i.e. a completion in progress). This replaces the use of semaphores for providing this exclusion and completion mechanism. SGI-PV: 981498 SGI-Modid: xfs-linux-melb:xfs-kern:31816a Signed-off-by: NDavid Chinner <david@fromorbit.com> Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
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由 Bernhard Walle 提交于
Various cleanup the drivers/firmware/memmap (after review by AKPM): - fix kdoc to conform to the standard - move kdoc from header to implementation files - remove superfluous WARN_ON() after kmalloc() - WARN_ON(x); if (!x) -> if(!WARN_ON(x)) - improve some comments Signed-off-by: NBernhard Walle <bwalle@suse.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Michael Abbott 提交于
The attached patch seems to already exist in a number of branches -- it keeps popping up on Google for me, and is certainly already in Debian -- but is strangely absent from mainstream. The problem appears to be that the patched file ends up as part of the target toolchain, but unfortunately the gcc constant folding doesn't appear to eliminate the __invalid_size_argument_for_IOC value early enough. Certainly compiling C++ programs which use _IO... macros as constants fails without this patch. Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Harvey Harrison 提交于
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Harvey Harrison 提交于
Collect the implementations from include/linux/byteorder/swab.h, swabb.h in swab.h The functionality provided covers: u16 swab16(u16 val) - return a byteswapped 16 bit value u32 swab32(u32 val) - return a byteswapped 32 bit value u64 swab64(u64 val) - return a byteswapped 64 bit value u32 swahw32(u32 val) - return a wordswapped 32 bit value u32 swahb32(u32 val) - return a high/low byteswapped 32 bit value Similar to above, but return swapped value from a naturally-aligned pointer u16 swab16p(u16 *p) u32 swab32p(u32 *p) u64 swab64p(u64 *p) u32 swahw32p(u32 *p) u32 swahb32p(u32 *p) Similar to above, but swap the value in-place (in-situ) void swab16s(u16 *p) void swab32s(u32 *p) void swab64s(u64 *p) void swahw32s(u32 *p) void swahb32s(u32 *p) Arches can override any of these with an optimized version by defining an inline in their asm/byteorder.h (example given for swab16()): u16 __arch_swab16() {} #define __arch_swab16 __arch_swab16 Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Alexey Dobriyan 提交于
Short enough reads from /proc/irq/*/smp_affinity return -EINVAL for no good reason. This became noticed with NR_CPUS=4096 patches, when length of printed representation of cpumask becase 1152, but cat(1) continued to read with 1024-byte chunks. bitmap_scnprintf() in good faith fills buffer, returns 1023, check returns -EINVAL. Fix it by switching to seq_file, so handler will just fill buffer and doesn't care about offsets, length, filling EOF and all this crap. For that add seq_bitmap(), and wrappers around it -- seq_cpumask() and seq_nodemask(). Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Reviewed-by: NPaul Jackson <pj@sgi.com> Cc: Mike Travis <travis@sgi.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Uwe Kleine-König 提交于
Signed-off-by: NUwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Haavard Skinnemoen 提交于
Specify how much physically continuous, DMA capable memory will be allocated at driver initialization time. This allow to create framebuffer device with larger virtual resolution. Combine with y-panning this can be used to implement double buffering acceleration method. Signed-off-by: NStanislaw Gruszka <stf_xl@wp.pl> Acked-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com> Acked-by: NKrzysztof Helt <krzysztof.h1@wp.pl> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jean Delvare 提交于
The legacy i2c model is going away soon, so switch to the new model. Signed-off-by: NJean Delvare <khali@linux-fr.org> Acked-by: NKrzysztof Helt <krzysztof.h1@wp.pl> Cc: Petr Vandrovec <VANDROVE@vc.cvut.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Miller 提交于
Some chips appear to have the 2D engine hang during screen redraw, typically in a sequence of copyarea operations. This appear to be solved by adding a flush of the engine destination pixel cache and waiting for the engine to be idle before issuing the accel operation. The performance impact seems to be fairly small. Here is a trace on an RV370 (PCI device ID 0x5b64), it records the RBBM_STATUS register, then the source x/y, destination x/y, and width/height used for the copy: ---------------------------------------- radeonfb_prim_copyarea: STATUS[00000140] src[210:70] dst[210:60] wh[a0:10] radeonfb_prim_copyarea: STATUS[00000140] src[2b8:70] dst[2b8:60] wh[88:10] radeonfb_prim_copyarea: STATUS[00000140] src[348:70] dst[348:60] wh[40:10] radeonfb_prim_copyarea: STATUS[80020140] src[390:70] dst[390:60] wh[88:10] radeonfb_prim_copyarea: STATUS[8002613f] src[40:80] dst[40:70] wh[28:10] radeonfb_prim_copyarea: STATUS[80026139] src[a8:80] dst[a8:70] wh[38:10] radeonfb_prim_copyarea: STATUS[80026133] src[e8:80] dst[e8:70] wh[80:10] radeonfb_prim_copyarea: STATUS[8002612d] src[170:80] dst[170:70] wh[30:10] radeonfb_prim_copyarea: STATUS[80026127] src[1a8:80] dst[1a8:70] wh[8:10] radeonfb_prim_copyarea: STATUS[80026121] src[1b8:80] dst[1b8:70] wh[88:10] radeonfb_prim_copyarea: STATUS[8002611b] src[248:80] dst[248:70] wh[68:10] ---------------------------------------- When things are going fine the copies complete before the next ROP is even issued, but all of a sudden the 2D unit becomes active (bit 17 in RBBM_STATUS) and the FIFO retry (bit 13) and FIFO pipeline busy (bit 14) are set as well. The FIFO begins to backup until it becomes full. What happens next is the radeon_fifo_wait() times out, and we access the chip illegally leading to a bus error which usually wedges the box. None of this makes it to the console screen, of course :-) radeon_fifo_wait() should be modified to reset the accelerator when this timeout happens instead of programming the chip anyways. ---------------------------------------- radeonfb: FIFO Timeout ! ERROR(0): Cheetah error trap taken afsr[0010080005000000] afar[000007f900800e40] TL1(0) ERROR(0): TPC[595114] TNPC[595118] O7[459788] TSTATE[11009601] ERROR(0): TPC<radeonfb_copyarea+0xfc/0x248> ERROR(0): M_SYND(0), E_SYND(0), Privileged ERROR(0): Highest priority error (0000080000000000) "Bus error response from system bus" ERROR(0): D-cache idx[0] tag[0000000000000000] utag[0000000000000000] stag[0000000000000000] ERROR(0): D-cache data0[0000000000000000] data1[0000000000000000] data2[0000000000000000] data3[0000000000000000] ERROR(0): I-cache idx[0] tag[0000000000000000] utag[0000000000000000] stag[0000000000000000] u[0000000000000000] l[00\ ERROR(0): I-cache INSN0[0000000000000000] INSN1[0000000000000000] INSN2[0000000000000000] INSN3[0000000000000000] ERROR(0): I-cache INSN4[0000000000000000] INSN5[0000000000000000] INSN6[0000000000000000] INSN7[0000000000000000] ERROR(0): E-cache idx[800e40] tag[000000000e049f4c] ERROR(0): E-cache data0[fffff8127d300180] data1[00000000004b5384] data2[0000000000000000] data3[0000000000000000] Ker:xnel panic - not syncing: Irrecoverable deferred error trap. ---------------------------------------- Another quirk is that these copyarea calls will not happen until the first drivers/char/vt.c:redraw_screen() occurs. This will only happen if you 1) VC switch or 2) run "consolechars" or 3) unblank the screen. This seems to happen because until a redraw_screen() the screen scrolling method used by fbcon is not finalized yet. I've seen this with other fb drivers too. So if all you do is boot straight into X you will never see this bug on the relevant chips. Signed-off-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jan Beulich 提交于
.. since a failed allocation is being (initially) handled gracefully, and panic()-ed upon failure explicitly in the function if retries with smaller sizes failed. Signed-off-by: NJan Beulich <jbeulich@novell.com> Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 8月, 2008 6 次提交
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由 Arjan van de Ven 提交于
The kernel has this really nice facility where if you put "initcall_debug" on the kernel commandline, it'll print which function it's going to execute just before calling an initcall, and then after the call completes it will 1) print if it had an error code 2) checks for a few simple bugs (like leaving irqs off) and 3) print how long the init call took in milliseconds. While trying to optimize the boot speed of my laptop, I have been loving number 3 to figure out what to optimize... ... and then I wished that the same thing was done for module loading. This patch makes the module loader use this exact same functionality; it's a logical extension in my view (since modules are just sort of late binding initcalls anyway) and so far I've found it quite useful in finding where things are too slow in my boot. Signed-off-by: NArjan van de Ven <arjan@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Christian Borntraeger 提交于
Hello Rusty, The entropy device was added after we exported all virtio headers. This patch adds virtio_rng.h to the exportable userspace headers. Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Rusty Russell 提交于
Out of line get_user_pages_fast fallback implementation, make it a weak symbol, get rid of CONFIG_HAVE_GET_USER_PAGES_FAST. Export the symbol to modules so lguest can use it. Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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由 Keith Packard 提交于
On my Intel chipset (965GM), the GTT is entirely erased across suspend/resume. This patch simply re-plays the current mapping at resume time to restore the table.=20 I noticed this once I started relying on persistent GTT mappings across VT switch in our GEM work -- the old X server and DRM code carefully unbind all memory from the GTT on VT switch, but GEM does not bother. I placed the list management and rewrite code in the generic layer on the assumption that it will be needed on other hardware, but I did not add the rewrite call to anything other than the Intel resume function. Keep a list of current GATT mappings. At resume time, rewrite them into the GATT. This is needed on Intel (at least) as the entire GATT is cleared across suspend/resume. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NKeith Packard <keithp@keithp.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NDave Airlie <airlied@redhat.com>
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由 Geert Uytterhoeven 提交于
Wire up for m68k{,nommu} the system calls that were added in the last merge window: - 4006553b ("flag parameters: inotify_init") - ed8cae8b ("flag parameters: pipe") - 336dd1f7 ("flag parameters: dup2") - a0998b50 ("flag parameters: epoll_create") - 9fe5ad9c ("flag parameters add-on: remove epoll_create size param") - b087498e ("flag parameters: eventfd") - 9deb27ba ("flag parameters: signalfd") Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org> Acked-by: NGreg Ungerer <gerg@uclinux.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Randy Dunlap 提交于
Fix function prototype in header file to match source code: linux-next-20080807/arch/x86/kernel/efi_64.c:100:14: error: symbol 'efi_ioremap' redeclared with different type (originally declared at include2/asm/efi.h:89) - different address spaces Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 11 8月, 2008 16 次提交
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由 Ingo Molnar 提交于
certain configs produce: [ 70.076229] BUG: MAX_LOCKDEP_KEYS too low! [ 70.080230] turning off the locking correctness validator. tune them up. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Paul Mackerras 提交于
It was only used by code in arch/ppc, and arch/ppc is gone, so remove the unused harrier_defs.h as well. Signed-off-by: NPaul Mackerras <paulus@samba.org>
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由 Peter Zijlstra 提交于
There is a overflow by 1 case in the new shrunken hlock code. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Eric W. Biederman 提交于
As pointed out and tracked by Yinghai Lu <yhlu.kernel@gmail.com>: Dhaval Giani got: kernel BUG at arch/x86/kernel/io_apic_64.c:357! invalid opcode: 0000 [1] SMP CPU 24 ... his system (x3950) has 8 ioapic, irq > 256 This was caused by: commit 9b7dc567 Author: Thomas Gleixner <tglx@linutronix.de> Date: Fri May 2 20:10:09 2008 +0200 x86: unify interrupt vector defines The interrupt vector defines are copied 4 times around with minimal differences. Move them all into asm-x86/irq_vectors.h It appears that Thomas did not notice that x86_64 does something completely different when he merge irq_vectors.h We can solve this for 2.6.27 by simply reintroducing the old heuristic for setting NR_IRQS on x86_64 to a usable value, which trivially removes the regression. Long term it would be nice to harmonize the handling of ioapic interrupts of x86_32 and x86_64 so we don't have this kind of confusion. Dhaval Giani <dhaval@linux.vnet.ibm.com> tested an earlier version of this patch by YH which confirms simply increasing NR_IRQS fixes the problem. Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Acked-by: NYinghai Lu <yhlu.kernel@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Mike Travis <travis@sgi.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Eric W. Biederman 提交于
Having cpu_online_map change during assign_irq_vector can result in some really nasty and weird things happening. The one that bit me last time was accessing non existent per cpu memory for non existent cpus. This locking was removed in a sloppy x86_64 and x86_32 merge patch. Guys can we please try and avoid subtly breaking x86 when we are merging files together? Signed-off-by: NEric W. Biederman <ebiederm@xmission.com> Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
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由 Ingo Molnar 提交于
the names were too generic: drivers/uio/uio.c:87: error: expected identifier or '(' before 'do' drivers/uio/uio.c:87: error: expected identifier or '(' before 'while' drivers/uio/uio.c:113: error: 'map_release' undeclared here (not in a function) Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Expose the new lock protection lock. This can be used to annotate places where we take multiple locks of the same class and avoid deadlocks by always taking another (top-level) lock first. NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
On Fri, 2008-08-01 at 16:26 -0700, Linus Torvalds wrote: > On Fri, 1 Aug 2008, David Miller wrote: > > > > Taking more than a few locks of the same class at once is bad > > news and it's better to find an alternative method. > > It's not always wrong. > > If you can guarantee that anybody that takes more than one lock of a > particular class will always take a single top-level lock _first_, then > that's all good. You can obviously screw up and take the same lock _twice_ > (which will deadlock), but at least you cannot get into ABBA situations. > > So maybe the right thing to do is to just teach lockdep about "lock > protection locks". That would have solved the multi-queue issues for > networking too - all the actual network drivers would still have taken > just their single queue lock, but the one case that needs to take all of > them would have taken a separate top-level lock first. > > Never mind that the multi-queue locks were always taken in the same order: > it's never wrong to just have some top-level serialization, and anybody > who needs to take <n> locks might as well do <n+1>, because they sure as > hell aren't going to be on _any_ fastpaths. > > So the simplest solution really sounds like just teaching lockdep about > that one special case. It's not "nesting" exactly, although it's obviously > related to it. Do as Linus suggested. The lock protection lock is called nest_lock. Note that we still have the MAX_LOCK_DEPTH (48) limit to consider, so anything that spills that it still up shit creek. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Most the free-standing lock_acquire() usages look remarkably similar, sweep them into a new helper. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Dave Jones 提交于
struct held_lock { u64 prev_chain_key; /* 0 8 */ struct lock_class * class; /* 8 8 */ long unsigned int acquire_ip; /* 16 8 */ struct lockdep_map * instance; /* 24 8 */ int irq_context; /* 32 4 */ int trylock; /* 36 4 */ int read; /* 40 4 */ int check; /* 44 4 */ int hardirqs_off; /* 48 4 */ /* size: 56, cachelines: 1 */ /* padding: 4 */ /* last cacheline: 56 bytes */ }; struct held_lock { u64 prev_chain_key; /* 0 8 */ long unsigned int acquire_ip; /* 8 8 */ struct lockdep_map * instance; /* 16 8 */ unsigned int class_idx:11; /* 24:21 4 */ unsigned int irq_context:2; /* 24:19 4 */ unsigned int trylock:1; /* 24:18 4 */ unsigned int read:2; /* 24:16 4 */ unsigned int check:2; /* 24:14 4 */ unsigned int hardirqs_off:1; /* 24:13 4 */ /* size: 32, cachelines: 1 */ /* padding: 4 */ /* bit_padding: 13 bits */ /* last cacheline: 32 bytes */ }; [mingo@elte.hu: shrunk hlock->class too] [peterz@infradead.org: fixup bit sizes] Signed-off-by: NDave Jones <davej@redhat.com> Signed-off-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
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由 Peter Zijlstra 提交于
this can be used to reset a held lock's subclass, for arbitrary-depth iterated data structures such as trees or lists which have per-node locks. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Peter Zijlstra 提交于
Some arch's can't handle sched_clock() being called too early - delay this until sched_clock_init() has been called. Reported-by: NBill Gatliff <bgat@billgatliff.com> Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: NNishanth Aravamudan <nacc@us.ibm.com> CC: Russell King - ARM Linux <linux@arm.linux.org.uk> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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由 Ian Molton 提交于
This patchset cleans up the TC6393XB support. * Add provision for the MMC subdevice * Disable / enable clocks on suspend / resume * Remove fragments of badly merged code (eg. linux/fb include etc.) * Use a device specific clock name to break dependancy on ARM/PXA2XX * Drop unnecessary resource names * Switch to tmio_io* accessors Signed-off-by: NIan Molton <spyro@f2s.com> Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>
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由 Ian Molton 提交于
This patch adds support for the TC6387XB. Unlike other TMIO devices this one has only one subdevice and no interrupt mux, however using the MFD framework allows it to share the TMIO MMC driver. Signed-off-by: NIan Molton <spyro@f2s.com> Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>
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由 Ian Molton 提交于
This patchset provides support for the core functinality of the T7L66XB SoC from Toshiba. Supported in this patchset is the IRQ MUX, MMC controller and NAND flash controller. Signed-off-by: NIan Molton <spyro@f2s.com> Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>
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由 Ian Molton 提交于
Signed-off-by: NIan Molton <spyro@f2s.com> Signed-off-by: NSamuel Ortiz <sameo@openedhand.com>
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- 09 8月, 2008 1 次提交
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由 Randy Dunlap 提交于
Fix fatal multi-line kernel-doc error in list.h: function short description must be on one line. Error(linux-2.6.27-rc2-git3//include/linux/list.h:318): duplicate section name 'Description' Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 8月, 2008 1 次提交
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由 Russell King 提交于
include/linux/i2c-pnx.h was missed when moving the include files. Fix it now; it doesn't really need to include mach/i2c.h at all. Successfully build tested with pnx4008_defconfig, which had failed in linux-next. Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
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