From: "David S. Miller" <davem@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: torvalds@osdl.org, akpm@osdl.org, linux-kernel@vger.kernel.org,
rlrevell@joe-job.com
Subject: Re: [patch] context-switching overhead in X, ioport(), 2.6.8.1
Date: Sat, 21 Aug 2004 21:46:32 -0700 [thread overview]
Message-ID: <20040821214632.62d58e40.davem@redhat.com> (raw)
In-Reply-To: <20040821135516.GA3872@elte.hu>
FWIW, I would recommend a sparse bitmap implementation for the
ioport stuff. Something simple like:
struct set_ent {
u32 pos;
u32 bits;
struct set_ent *next;
};
static inline int is_set(struct set_ent *head, int pos)
{
while (head != NULL) {
if (pos >= head->pos) {
if (pos < head->pos + 32) {
if (head->bits &
(1 << (pos - head->pos)))
return 1;
}
break;
}
head = head->next;
}
return 0;
}
You get the idea.
next prev parent reply other threads:[~2004-08-22 4:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-21 13:55 [patch] context-switching overhead in X, ioport(), 2.6.8.1 Ingo Molnar
2004-08-22 4:46 ` David S. Miller [this message]
2004-08-22 5:42 ` Ryan Cumming
2004-08-22 6:00 ` Lee Revell
2004-08-22 6:06 ` Ryan Cumming
[not found] <2vEzI-Vw-17@gated-at.bofh.it>
2004-08-22 12:16 ` Andi Kleen
2004-08-22 12:00 ` Alan Cox
2004-08-22 14:23 ` Andi Kleen
2004-08-22 14:47 ` Alan Cox
2004-08-22 17:31 ` Ingo Molnar
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