Messages in this thread | | | Date | Tue, 23 Sep 2014 00:12:58 -0400 | From | Tejun Heo <> | Subject | Re: [PATCH] kernfs: use stack-buf for small writes. |
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Hello, Neil.
On Tue, Sep 23, 2014 at 02:06:33PM +1000, NeilBrown wrote: > When mdmon needs to update metadata after a device failure in an array > there are two 'kmalloc' sources that can trigger deadlock if memory is tight > and needs to be written to the array (which cannot be allowed until mdmon > updates the metadata). > One is in O_DIRECT writes which I have patches for. The other is when > writing to the sysfs file to tell md that it is safe to continue. > This simple patch removes the second.
Ugh... :( If this can't be avoided at all, I'd much prefer it to be something explicit - a flag marking the file as needing a persistent write buffer which is allocated on open. "Small" writes on stack feels way to implicit to me.
Thanks.
-- tejun
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