Messages in this thread | | | From | Eric Dumazet <> | Subject | Re: [patch] epoll use a single inode ... | Date | Wed, 7 Mar 2007 19:52:13 +0100 |
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> Not only might memcpy() do a "prefetch for read" on the source for some > architectures (which in turn may end up being slow for an address that > isn't in the TLB, like NULL), but you depend on a very much internal
Well, I hope a prefetch(NULL) is OK because we are doing millions of them (see include/linux/list.h :) )
> detail, since it *could* have been using something like > > memcpy(dname, name->name, name->len+1); >
Yes very true, I will change that and push to Andrew for mm testing
I was thinking about being able to cache the name into the dentry, do you think it's worth the pain ? (its not SMP safe for example...)
static char * pipefs_dname(struct dentry *dentry, char *buffer, int buflen) { if (!dentry->d_iname[0]) snprintf(dentry->d_iname, DNAME_INLINE_LEN_MIN, "pipe:[%lu]", dentry->d_inode->i_ino); strlcpy(buffer, dentry->d_iname, buflen); return buffer; } - 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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