Jacek Galowicz [Sun, 4 Dec 2011 23:33:31 +0000 (10:33 +1100)]
lguest: switch segment-voodoo-numbers to readable symbols
When studying lguest's x86 segment descriptor code, it is not longer
necessary to have the Intel x86 architecture manual open on the page
with the segment descriptor illustration to understand the crazy
numbers assigned to both descriptor structure halves a/b.
Now the struct desc_struct's fields, like suggested by
Glauber de Oliveira Costa in 2008, are used.
Signed-off-by: Jacek Galowicz <jacek@galowicz.de> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Kevin Cernekee [Sun, 4 Dec 2011 23:33:31 +0000 (10:33 +1100)]
module: Fix performance regression on modules with large symbol tables
Looking at /proc/kallsyms, one starts to ponder whether all of the extra
strtab-related complexity in module.c is worth the memory savings.
Instead of making the add_kallsyms() loop even more complex, I tried the
other route of deleting the strmap logic and naively copying each string
into core_strtab with no consideration for consolidating duplicates.
Performance on an "already exists" insmod of nvidia.ko (runs
add_kallsyms() but does not actually initialize the module):
Original scheme: 1.230s
With naive copying: 0.058s
Extra space used: 35k (of a 408k module).
Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <73defb5e4bca04a6431392cc341112b1@localhost>
Rusty Russell [Sun, 4 Dec 2011 23:33:30 +0000 (10:33 +1100)]
virtio: add debugging if driver doesn't kick.
Under the existing #ifdef DEBUG, check that they don't have more than
1/10 of a second between an add_buf() and a
virtqueue_notify()/virtqueue_kick_prepare() call.
We could get false positives on a really busy system, but good for
development.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell [Sun, 4 Dec 2011 23:33:30 +0000 (10:33 +1100)]
virtio: expose added descriptors immediately.
A virtio driver does virtqueue_add_buf() multiple times before finally
calling virtqueue_kick(); previously we only exposed the added buffers
in the virtqueue_kick() call. This means we don't need a memory
barrier in virtqueue_add_buf(), but it reduces concurrency as the
device (ie. host) can't see the buffers until the kick.
In the unusual (but now possible) case where a driver does add_buf()
and get_buf() without doing a kick, we do need to insert one before
our counter wraps. Otherwise we could wrap num_added, and later on
not realize that we have passed the marker where we should have
kicked.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty Russell [Sun, 4 Dec 2011 23:33:29 +0000 (10:33 +1100)]
virtio: support unlocked queue kick
Based on patch by Christoph for virtio_blk speedup:
Split virtqueue_kick to be able to do the actual notification
outside the lock protecting the virtqueue. This patch was
originally done by Stefan Hajnoczi, but I can't find the
original one anymore and had to recreated it from memory.
Pointers to the original or corrections for the commit message
are welcome.
Rusty Russell [Sun, 4 Dec 2011 23:33:29 +0000 (10:33 +1100)]
virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Christoph Hellwig <hch@lst.de>
Linus Torvalds [Sun, 4 Dec 2011 19:57:09 +0000 (11:57 -0800)]
x86: Fix boot failures on older AMD CPU's
People with old AMD chips are getting hung boots, because commit bcb80e53877c ("x86, microcode, AMD: Add microcode revision to
/proc/cpuinfo") moved the microcode detection too early into
"early_init_amd()".
At that point we are *so* early in the booth that the exception tables
haven't even been set up yet, so the whole
doesn't actually work: if the rdmsr does a GP fault (due to non-existant
MSR register on older CPU's), we can't fix it up yet, and the boot fails.
Fix it by simply moving the code to a slightly later point in the boot
(init_amd() instead of early_init_amd()), since the kernel itself
doesn't even really care about the microcode patchlevel at this point
(or really ever: it's made available to user space in /proc/cpuinfo, and
updated if you do a microcode load).
Reported-tested-and-bisected-by: Larry Finger <Larry.Finger@lwfinger.net> Tested-by: Bob Tracy <rct@gherkin.frus.com> Acked-by: Borislav Petkov <borislav.petkov@amd.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Eric Dumazet [Sat, 3 Dec 2011 21:39:53 +0000 (21:39 +0000)]
tcp: take care of misalignments
We discovered that TCP stack could retransmit misaligned skbs if a
malicious peer acknowledged sub MSS frame. This currently can happen
only if output interface is non SG enabled : If SG is enabled, tcp
builds headless skbs (all payload is included in fragments), so the tcp
trimming process only removes parts of skb fragments, header stay
aligned.
Some arches cant handle misalignments, so force a head reallocation and
shrink headroom to MAX_TCP_HEADER.
Dont care about misaligments on x86 and PPC (or other arches setting
NET_IP_ALIGN to 0)
This patch introduces __pskb_copy() which can specify the headroom of
new head, and pskb_copy() becomes a wrapper on top of __pskb_copy()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Meyer [Fri, 2 Dec 2011 12:36:13 +0000 (12:36 +0000)]
sfc: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Meyer [Fri, 2 Dec 2011 12:35:43 +0000 (12:35 +0000)]
ll_temac: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Meyer [Tue, 29 Nov 2011 11:08:00 +0000 (11:08 +0000)]
enic: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas Meyer [Tue, 29 Nov 2011 11:08:00 +0000 (11:08 +0000)]
bnx2x: Use kcalloc instead of kzalloc to allocate array
The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.
The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107
Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: David S. Miller <davem@davemloft.net>
projects / karo-tx-linux.git / log