Hi Vaibhav,
Le 13/10/2016 à 13:08, Vaibhav Jain a écrit :
This patch prevents resetting the cxl adapter via sysfs in presence of one or more active cxl_context on it. This protects against an unrecoverable error caused by PSL owning a dirty cache line even after reset and host tries to touch the same cache line. In case a force reset of the card is required irrespective of any active contexts, the int value -1 can be stored in the 'reset' sysfs attribute of the card. The patch introduces a new atomic_t member named contexts_num inside struct cxl that holds the number of active context attached to the card , which is checked against '0' before proceeding with the reset. To prevent against a race condition where a context is activated just after reset check is performed, the contexts_num is atomically set to '-1' after reset-check to indicate that no more contexts can be activated on the card anymore. Before activating a context we atomically test if contexts_num is non-negative and if so, increment its value by one. In case the value of contexts_num is negative then it indicates that the card is about to be reset and context activation is error-ed out at that point. Signed-off-by: Vaibhav Jain <vaib...@linux.vnet.ibm.com>
Looks good to me, thanks! And sorry, I could have saved you an iteration. Reviewed-by: Frederic Barrat <fbar...@linux.vnet.ibm.com> Actually, I guess I'm supposed to do that now: Acked-by: Frederic Barrat <fbar...@linux.vnet.ibm.com> Fred
