Bug 1458586

Summary:	kernel 4.11.3 causes resolv/tst-resolv-res_init-thread in glibc to timeout
Product:	[Fedora] Fedora	Reporter:	H.J. Lu <hongjiu.lu>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED DUPLICATE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	25	CC:	fweimer, gansalmon, ichavero, itamar, jonathan, kernel-maint, madhu.chinakonda, mchehab
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Last Closed:	2017-06-04 15:28:16 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Description H.J. Lu 2017-06-04 15:15:02 UTC

This commit in kernel 4.11.3:

commit c0303efeab7391ec51c337e0ac5740860ad01fe7
Author: Jesper Dangaard Brouer <brouer>
Date:   Mon Jan 9 16:04:09 2017 +0100

    net: reduce cycles spend on ICMP replies that gets rate limited

    This patch split the global and per (inet)peer ICMP-reply limiter
    code, and moves the global limit check to earlier in the packet
    processing path.  Thus, avoid spending cycles on ICMP replies that
    gets limited/suppressed anyhow.

    The global ICMP rate limiter icmp_global_allow() is a good solution,
    it just happens too late in the process.  The kernel goes through the
    full route lookup (return path) for the ICMP message, before taking
    the rate limit decision of not sending the ICMP reply.

    Details: The kernels global rate limiter for ICMP messages got added
    in commit 4cdf507d5452 ("icmp: add a global rate limitation").  It is
    a token bucket limiter with a global lock.  It brilliantly avoids
    locking congestion by only updating when 20ms (HZ/50) were elapsed. It
    can then avoids taking lock when credit is exhausted (when under
    pressure) and time constraint for refill is not yet meet.

    Signed-off-by: Jesper Dangaard Brouer <brouer>
    Acked-by: Eric Dumazet <edumazet>
    Signed-off-by: David S. Miller <davem>

caused resolv/tst-resolv-res_init and resolv/tst-resolv-res_init-thread
on glibc master branch to timeout.

Comment 1 Florian Weimer 2017-06-04 15:28:16 UTC


*** This bug has been marked as a duplicate of bug 1458542 ***