Messages in this thread | | | Date | Wed, 24 May 2006 00:26:09 +0400 | From | "Alexey Polyakov" <> | Subject | Re: [PATCH] updated reiser4 - reduced cpu usage for writes by writing more than 4k at a time (has implications for generic write code and eventually for the IO layer) |
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Hi!
I'm actively using Reiser4 on a production servers (and I know a lot of people that do that too). Could you please release the patch against the vanilla tree? I don't think there's a lot of people that will test -mm version, especially on production servers - -mm is a little bit too unstable.
Thanks.
On 5/24/06, Hans Reiser <reiser@namesys.com> wrote: > ftp://ftp.namesys.com/pub/reiser4-for-2.6/2.6.17-rc4-mm1/reiser4-for-2.6.17-rc4-mm1-2.patch.gz > > The referenced patch replaces all reiser4 patches to mm. It revises the > existing reiser4 code to do a good job for writes that are larger than > 4k at a time by assiduously adhering to the principle that things that > need to be done once per write should be done once per write, not once > per 4k. That statement is a slight simplification: there are times when > due to the limited size of RAM you want to do some things once per > WRITE_GRANULARITY, where WRITE_GRANULARITY is a #define that defines > some moderate number of pages to write at once. This code empirically > proves that the generic code design which passes 4k at a time to the > underlying FS can be improved. Performance results show that the new > code consumes 40% less CPU when doing "dd bs=1MB ....." (your hardware, > and whether the data is in cache, may vary this result). Note that this > has only a small effect on elapsed time for most hardware. > > The planned future(as discussed with akpm previously): we will ship > very soon (testing it now) an improved reiser4 read code that does reads > in more than little 4k chunks. Then we will revise the generic code to > allow an FS to receive the writes and reads in whole increments. How > best to revise the generic code is still being discussed. Nate is > discussing doing it in some way that improves code symmetry in the io > scheduler layer as well, if there is interest by others in it maybe a > thread can start on that topic, or maybe it can wait for him+zam to make > a patch. > > Note for users: this patch also contains numerous important bug fixes. > > - > 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/ >
-- Alexey Polyakov - 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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