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    SubjectRe: [patch 1/4] Linux Kernel Markers - Architecture Independent Code
    * Rusty Russell (rusty@rustcorp.com.au) wrote:
    > On Fri, 2007-08-24 at 12:26 -0400, Mathieu Desnoyers wrote:
    > > * Rusty Russell (rusty@rustcorp.com.au) wrote:
    > > > On Mon, 2007-08-20 at 16:27 -0400, Mathieu Desnoyers wrote:
    > > > > +{
    > > > > + struct hlist_head *head;
    > > > > + struct hlist_node *node;
    > > > > + struct marker_entry *e;
    > > > > + size_t len = strlen(name) + 1;
    > > > > + u32 hash = jhash(name, len-1, 0);
    > > > > +
    > > > > + head = &marker_table[hash & ((1 << MARKER_HASH_BITS)-1)];
    > > > > + hlist_for_each_entry(e, node, head, hlist) {
    > > > > + if (!strcmp(name, e->name))
    > > > > + return e;
    > > > > + }
    > > > > + return NULL;
    > > > > +}
    > > >
    > > > OK, don't understand the strlen, len, len-1 dance here?
    > > >
    > >
    > > Let's say we have abc\0 for marker name as name input.
    > >
    > > len = 3 + 1 = 4 (including \0)
    > > hash is done only on the 3 first chars, excluding the \0 (therefore the
    > > len-1 there)
    > >
    > > Actually, it's like this only for a matter of consistency between
    > > add_marker and remove_marker, which are quite similar, but add_marker
    > > needs name_len to include the \0 value. It would be odd to change the
    > > logic between the two functions to one including the \0 and the other
    > > excluding it.
    >
    > Sure, but that doesn't really explain why the code does:
    >
    > size_t len = strlen(name) + 1;
    > u32 hash = jhash(name, len-1, 0);
    >
    > Rather than:
    >
    > u32 hash = jhash(name, strlen(name), 0);
    >

    Yup, good point. Fixed.

    Thanks,

    Mathieu

    > > Thanks for the review,
    >
    > That's fine, just some light reading...
    >
    > Cheers,
    > Rusty.
    > >
    >

    --
    Mathieu Desnoyers
    Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
    OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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