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| author | Juergen Gross <jgross@suse.com> | 2021-10-05 15:34:33 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-13 10:08:17 +0200 |
| commit | 2abb4077fa1b88b147c74d0973afc0bf0bdeafd1 (patch) | |
| tree | 2ae9632c6bdc22f3a3d9255f7e144e63223c6ed5 | |
| parent | 42fbcbaa8a99381c013577fd0127906528cfc996 (diff) | |
| download | linux-stable-2abb4077fa1b88b147c74d0973afc0bf0bdeafd1.tar.gz linux-stable-2abb4077fa1b88b147c74d0973afc0bf0bdeafd1.tar.bz2 linux-stable-2abb4077fa1b88b147c74d0973afc0bf0bdeafd1.zip | |
xen/balloon: fix cancelled balloon action
commit 319933a80fd4f07122466a77f93e5019d71be74c upstream.
In case a ballooning action is cancelled the new kernel thread handling
the ballooning might end up in a busy loop.
Fix that by handling the cancelled action gracefully.
While at it introduce a short wait for the BP_WAIT case.
Cc: stable@vger.kernel.org
Fixes: 8480ed9c2bbd56 ("xen/balloon: use a kernel thread instead a workqueue")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: https://lore.kernel.org/r/20211005133433.32008-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/xen/balloon.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index be31c296eed4..07f362c63ae9 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -508,12 +508,12 @@ static enum bp_state decrease_reservation(unsigned long nr_pages, gfp_t gfp) } /* - * Stop waiting if either state is not BP_EAGAIN and ballooning action is - * needed, or if the credit has changed while state is BP_EAGAIN. + * Stop waiting if either state is BP_DONE and ballooning action is + * needed, or if the credit has changed while state is not BP_DONE. */ static bool balloon_thread_cond(enum bp_state state, long credit) { - if (state != BP_EAGAIN) + if (state == BP_DONE) credit = 0; return current_credit() != credit || kthread_should_stop(); @@ -533,10 +533,19 @@ static int balloon_thread(void *unused) set_freezable(); for (;;) { - if (state == BP_EAGAIN) - timeout = balloon_stats.schedule_delay * HZ; - else + switch (state) { + case BP_DONE: + case BP_ECANCELED: timeout = 3600 * HZ; + break; + case BP_EAGAIN: + timeout = balloon_stats.schedule_delay * HZ; + break; + case BP_WAIT: + timeout = HZ; + break; + } + credit = current_credit(); wait_event_freezable_timeout(balloon_thread_wq, |