Messages in this thread Patch in this message | | | Date | Mon, 3 Mar 2003 16:20:22 +0000 | From | Matthew Wilcox <> | Subject | Stack usage in random.c |
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Jeff Garzik whined about how much stack space was being used by extract_entropy(). So I went and looked and reclaimed 352 bytes of stack. Damn SHA ...
It's actually worse (better?) than that -- xfer_secondary_pool() can call extract_entropy() again, so I may have saved over 700 bytes of stack usage here. It's safe for xfer_secondary_pool() to share its parent's tmp because it hasn't been used at this point.
--- linux-2.5.63/drivers/char/random.c 2003-02-24 13:05:06.000000000 -0600 +++ linux-2.5.63-random/drivers/char/random.c 2003-03-03 08:05:24.000000000 -0600 @@ -1228,10 +1228,8 @@ * at which point we do a "catastrophic reseeding". */ static inline void xfer_secondary_pool(struct entropy_store *r, - size_t nbytes) + size_t nbytes, __u32 *tmp) { - __u32 tmp[TMP_BUF_SIZE]; - if (r->entropy_count < nbytes * 8 && r->entropy_count < r->poolinfo.POOLBITS) { int nwords = min_t(int, @@ -1284,7 +1282,7 @@ r->entropy_count = r->poolinfo.POOLBITS; if (flags & EXTRACT_ENTROPY_SECONDARY) - xfer_secondary_pool(r, nbytes); + xfer_secondary_pool(r, nbytes, tmp); DEBUG_ENT("%s has %d bits, want %d bits\n", r == sec_random_state ? "secondary" : -- "It's not Hollywood. War is real, war is primarily not about defeat or victory, it is about death. I've seen thousands and thousands of dead bodies. Do you think I want to have an academic debate on this subject?" -- Robert Fisk - 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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