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author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-06-07 19:26:03 (GMT) |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-06-10 14:14:33 (GMT) |
commit | b2c75c446ae72387916e2caf6e6dca815b6e5e6e (patch) | |
tree | 5b97f2908fec2b03b6dfef5f52d5e79f2597f750 /arch/x86 | |
parent | 466318a87f28cb3ba0d08a3b7ef1a37ae73d5aa7 (diff) | |
download | linux-fsl-qoriq-b2c75c446ae72387916e2caf6e6dca815b6e5e6e.tar.xz |
xen/tmem: Don't over-write tmem_frontswap_poolid after tmem_frontswap_init set it.
Commit 10a7a0771399a57a297fca9615450dbb3f88081a ("xen: tmem: enable Xen
tmem shim to be built/loaded as a module") allows the tmem module
to be loaded any time. For this work the frontswap API had to
be able to asynchronously to call tmem_frontswap_init before
or after the swap image had been set. That was added in git
commit 905cd0e1bf9ffe82d6906a01fd974ea0f70be97a
("mm: frontswap: lazy initialization to allow tmem backends to build/run as modules").
Which means we could do this (The common case):
modprobe tmem [so calls frontswap_register_ops, no ->init]
modifies tmem_frontswap_poolid = -1
swapon /dev/xvda1 [__frontswap_init, calls -> init, tmem_frontswap_poolid is
< 0 so tmem hypercall done]
Or the failing one:
swapon /dev/xvda1 [calls __frontswap_init, sets the need_init bitmap]
modprobe tmem [calls frontswap_register_ops, -->init calls, finds out
tmem_frontswap_poolid is 0, does not make a hypercall.
Later in the module_init, sets tmem_frontswap_poolid=-1]
Which meant that in the failing case we would not call the hypercall
to initialize the pool and never be able to make any frontswap
backend calls.
Moving the frontswap_register_ops after setting the tmem_frontswap_poolid
fixes it.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Diffstat (limited to 'arch/x86')
0 files changed, 0 insertions, 0 deletions