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Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas event lost

From wangyijing <wangyijing@huawei.com>
Newsgroups linux.kernel
Subject Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas event lost
Date 2017-07-12 04:10 +0200
Message-ID <u2fgd-1TD-7@gated-at.bofh.it> (permalink)
References <u1AZr-1Sl-3@gated-at.bofh.it> <u1AZs-1Sl-17@gated-at.bofh.it> <u25qy-454-45@gated-at.bofh.it>
Organization linux.* mail to news gateway

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>> -    unsigned long port_events_pending;
>> -    unsigned long phy_events_pending;
>> +    struct asd_sas_event   port_events[PORT_POOL_SIZE];
>> +    struct asd_sas_event   phy_events[PHY_POOL_SIZE];
>>
>>      int error;
> 
> Hi Yijing,
> 
> So now we are creating a static pool of events per PHY/port, instead of having 1 static work struct per event per PHY/port. So, for sure, this avoids the dynamic event issue of system memory exhaustion which we discussed in v1+v2 series. And it seems to possibly remove issue of losing SAS events.
> 
> But how did you determine the pool size for a PHY/port? It would seem to be 5 * #phy events or #port events (which is also 5, I figure by coincidence). How does this deal with flutter of >25 events?

There is no special meaning for the pool size, if flutter of > 25 events, notify sas events will return error, and the further step work is depending on LLDD drivers.
I hope libsas could do more work in this case, but now it seems a little difficult, this patch may be a interim fix, until we find a perfect solution.

Thanks!
Yijing.

> 
> Thanks,
> John
> 
> 
> .
> 

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Thread

[PATCH v3 1/7] libsas: Use static sas event pool to appease sas event lost Yijing Wang <wangyijing@huawei.com> - 2017-07-10 09:10 +0200
  Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost John Garry <john.garry@huawei.com> - 2017-07-11 17:40 +0200
    Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost wangyijing <wangyijing@huawei.com> - 2017-07-12 04:10 +0200
      Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost John Garry <john.garry@huawei.com> - 2017-07-12 10:20 +0200
        Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost wangyijing <wangyijing@huawei.com> - 2017-07-12 10:50 +0200
          Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost John Garry <john.garry@huawei.com> - 2017-07-12 12:20 +0200
            Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost wangyijing <wangyijing@huawei.com> - 2017-07-13 04:20 +0200
  Re: [PATCH v3 1/7] libsas: Use static sas event pool to appease sas  event lost Hannes Reinecke <hare@suse.de> - 2017-07-14 08:50 +0200

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