Searched hist:"9641 b784" (Results 1 – 3 of 3) sorted by relevance
/openbmc/linux/fs/jffs2/ |
H A D | summary.h | 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes
This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to.
We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do.
Signed-off-by: David Woodhouse <dwmw2@infradead.org> 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to. We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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H A D | summary.c | 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes
This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to.
We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do.
Signed-off-by: David Woodhouse <dwmw2@infradead.org> 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to. We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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H A D | scan.c | 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes
This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to.
We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do.
Signed-off-by: David Woodhouse <dwmw2@infradead.org> 9641b784 Sat May 20 10:13:34 CDT 2006 David Woodhouse <dwmw2@infradead.org> [JFFS2] Optimise reading of eraseblock summary nodes This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to. We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do. Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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