Messages in this thread | | | Date | Mon, 20 Jan 2003 15:21:19 +0100 | From | Jan Hudec <> | Subject | Re: Disabling file system caching |
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On Mon, Jan 20, 2003 at 01:17:42PM +0530, Balbir wrote: > Not sure if posting to the newsgroup linux.kernel sends > it to the mailing list too. > > "Balbir Singh" <balbir_soni@yahoo.com> wrote in message > news:b0g6q2$lfq$1@tilde.itg.ti.com... > > "Rik van Riel" <riel@conectiva.com.br> wrote in message > > news:20030120011009$2d98@gated-at.bofh.it... > > > On Sun, 19 Jan 2003, Jean-Eric Cuendet wrote: > > > > > > > Is it possible to disable file caching for a given partition or mount? > > > > > > No, if you do that mmap(), read(), write() etc. would be impossible. > > > > > > > Or at least to limit it at a certain quantity of memory? > > > > > > Not yet. I'm thinking of implementing something like this > > > for the next version of -rmap (reclaim only from the cache > > > if the cache occupies more than a certain fraction of ram). > > > > I think that this feature is very important. In an embedded system > using an NFS root filesystem, we found that the file cache > would take a lot of memory and all insmods would fail. This is > especially true when the system boots up and looks for /lib/modules. > > I think it should be possible to modify the slab allocator to > implement a memory pool. We could add a flag which would prevent > the slab from growing beyond its initial size. > > This approach would work only if the cache is allocated by > using the slab allocator.
No, it's not! And the slab alocator should mercilessly rip the cache when it needs some pages. In the NFS root case, I would guess it's a problem of NFS implementation allocating too much kernel memory, since both cache and user-land pages are riped in favor of kernel allocations.
------------------------------------------------------------------------------- Jan 'Bulb' Hudec <bulb@ucw.cz> - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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