Re: [PATCH] reduce stack usage of NFS (was Re: How to safely reduce...)

[Randy.Dunlap]

Denis Vlasenko wrote:
> > > > I can convert these into kmalloc'ed variants but hesitate to do so
> > > > because of possible 'need to kmalloc in order to free memory for kmalloc'
> > > > deadlocks.
> > >
> > > how about a memory pool?
> > >
> > > It's not THE solution but I suspect the depth of callchains of these isn't too deep so it would work
> >
> > I can't see that any of the callchains Denis listed can deadlock. None
> > of them appear to lie in the memory reclaim paths.
>
>
> This patch reduces stack usage to below 100 bytes for
> the following functions:
>
>                        stack usage in 2.6.9
> nfs3_proc_create:             544
> _nfs4_do_open:                516
> nfs_readdir:                  412
> nfs_symlink:                  368
> _nfs4_open_delegation_recall: 368
> nfs3_proc_rename:             364
> _nfs4_open_reclaim:           364
> nfs_mknod:                    352
> nfs_mkdir:                    352
> nfs_proc_create:              344
> nfs3_proc_link:               328
> nfs_lookup_revalidate:        312
> nfs_lookup:                   292
>
> (btw: in function nfs_readdir: local variable 'desc' seem to be
> easily replaceable with &my_desc, or am I missing something?)
>
> Compile tested only. I can't run test it until next Wednesday :(
>
> Please review, especially for leaks on error paths.

Hi Denis,
I checked all of it.  Looks right & it builds.

--
~Randy
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