----- Original Message ----- > On 08/22/2012 12:54 PM, Avi Kivity wrote: > > On 08/21/2012 12:28 PM, Tomas Racek wrote: > >> > >> http://fi.muni.cz/~xracek/debian2.img.bz2 > >> > >> Other things are the same. > >> > >> The runtest.sh sets environment for xfstests and runs test 285 > >> which I wrote and and which should test if FS sends discard > >> requests only on free sectors: > >> 285: > >> 1. Create loop device and FS on it. > >> 2. Populate it with some garbage. > >> 3. Get free sectors from FS. > >> 4. Run fstrim and look for discard requests via blk tracer. > >> 5. Compare free sectors to discard requests. > >> > >> The test itself can have some issues but I'm pretty sure it > >> shouldn't crash the system. ;-) > > > > Does the following patch help? > > > > It's obvious that it should. You're running a non-modular kernel, > and those nops are discarded (probably a leftover from the days > patching was a boot-only activity), so the kernel patched garbage > over its own code. > Works fine. Thank you! Tom > -------8<----cut-here-----8<----------------------------------- > > From: Avi Kivity <avi@xxxxxxxxxx> > Date: Wed, 22 Aug 2012 12:58:18 +0300 > Subject: [PATCH] x86, alternative: fix p6 nops on non-modular kernels > > Probably a leftover from the early days of self-patching, p6nops are > marked __initconst_or_module, which causes them to be discarded in a > non-modular kernel. If something later triggers patching, it will > overwrite kernel code with garbage. > > Reported-by: Tomas Racek <tracek@xxxxxxxxxx> > Signed-off-by: Avi Kivity <avi@xxxxxxxxxx> > > diff --git a/arch/x86/kernel/alternative.c > b/arch/x86/kernel/alternative.c > index afb7ff7..ced4534 100644 > --- a/arch/x86/kernel/alternative.c > +++ b/arch/x86/kernel/alternative.c > @@ -165,7 +165,7 @@ static int __init setup_noreplace_paravirt(char > *str) > #endif > > #ifdef P6_NOP1 > -static const unsigned char __initconst_or_module p6nops[] = > +static const unsigned char p6nops[] = > { > P6_NOP1, > P6_NOP2, > > > -- > error compiling committee.c: too many arguments to function > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
