From: Luis Chamberlain <mcgrof@kernel.org>
To: Song Liu <songliubraving@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
Mike Rapoport <rppt@kernel.org>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"bpf@vger.kernel.org" <bpf@vger.kernel.org>,
"hch@infradead.org" <hch@infradead.org>,
"ast@kernel.org" <ast@kernel.org>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"song@kernel.org" <song@kernel.org>,
Kernel Team <Kernel-team@fb.com>,
"pmladek@suse.com" <pmladek@suse.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"hpa@zytor.com" <hpa@zytor.com>,
"dborkman@redhat.com" <dborkman@redhat.com>,
"edumazet@google.com" <edumazet@google.com>,
"bp@alien8.de" <bp@alien8.de>, "mbenes@suse.cz" <mbenes@suse.cz>,
"imbrenda@linux.ibm.com" <imbrenda@linux.ibm.com>,
Davidlohr Bueso <dave@stgolabs.net>
Subject: Re: [PATCH v4 bpf 0/4] vmalloc: bpf: introduce VM_ALLOW_HUGE_VMAP
Date: Wed, 20 Apr 2022 11:28:07 -0700 [thread overview]
Message-ID: <YmBQt1RjDY1hGQlJ@bombadil.infradead.org> (raw)
In-Reply-To: <3F75142B-3E87-4195-A026-3A7F1E595960@fb.com>
On Wed, Apr 20, 2022 at 02:42:37PM +0000, Song Liu wrote:
> For (b), we have seen direct map fragmentation causing visible
> performance drop for our major services. This is the shadow
> production benchmark, so it is not possible to run it out of
> our data centers. Tracing showed that BPF program was the top
> trigger of these direct map splits.
It's often not easy to reproduce issues like these, but I've
ran into that before for other Proof of Concept issues before
and the solution has been a Linux selftest. For instance a
"multithreaded" bombing for kmod can be triggered with
lib/test_kmod.c and tools/testing/selftests/kmod/kmod.sh
Would desinging a selftest to abuse eBPF JIT be a possible
way to reproduce the issue?
Luis
next prev parent reply other threads:[~2022-04-20 18:28 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220415164413.2727220-1-song@kernel.org>
[not found] ` <20220415164413.2727220-2-song@kernel.org>
2022-04-15 17:43 ` [PATCH v4 bpf 1/4] vmalloc: replace VM_NO_HUGE_VMAP with VM_ALLOW_HUGE_VMAP Rik van Riel
[not found] ` <20220415164413.2727220-3-song@kernel.org>
2022-04-15 17:43 ` [PATCH v4 bpf 2/4] page_alloc: use vmalloc_huge for large system hash Rik van Riel
2022-04-25 7:07 ` Geert Uytterhoeven
2022-04-25 8:17 ` Linus Torvalds
2022-04-25 8:24 ` Geert Uytterhoeven
[not found] ` <20220415164413.2727220-4-song@kernel.org>
2022-04-15 18:06 ` [PATCH v4 bpf 3/4] module: introduce module_alloc_huge Rik van Riel
2022-06-16 16:10 ` Dave Hansen
2022-04-15 19:05 ` [PATCH v4 bpf 0/4] vmalloc: bpf: introduce VM_ALLOW_HUGE_VMAP Luis Chamberlain
2022-04-16 1:34 ` Song Liu
2022-04-16 1:42 ` Luis Chamberlain
2022-04-16 1:43 ` Luis Chamberlain
2022-04-16 5:08 ` Christoph Hellwig
2022-04-16 19:55 ` Song Liu
2022-04-16 20:30 ` Linus Torvalds
2022-04-16 22:26 ` Song Liu
2022-04-18 10:06 ` Mike Rapoport
2022-04-19 0:44 ` Luis Chamberlain
2022-04-19 1:56 ` Edgecombe, Rick P
2022-04-19 5:36 ` Song Liu
2022-04-19 18:42 ` Mike Rapoport
2022-04-19 19:20 ` Linus Torvalds
2022-04-20 2:03 ` Alexei Starovoitov
2022-04-20 2:18 ` Linus Torvalds
2022-04-20 14:42 ` Song Liu
2022-04-20 18:28 ` Luis Chamberlain [this message]
2022-04-21 3:25 ` Nicholas Piggin
2022-04-21 5:48 ` Linus Torvalds
2022-04-21 6:02 ` Linus Torvalds
2022-04-21 9:07 ` Nicholas Piggin
2022-04-21 8:57 ` Nicholas Piggin
2022-04-21 15:44 ` Linus Torvalds
2022-04-21 23:30 ` Nicholas Piggin
2022-04-22 0:49 ` Linus Torvalds
2022-04-22 1:51 ` Nicholas Piggin
2022-04-22 2:31 ` Linus Torvalds
2022-04-22 2:57 ` Nicholas Piggin
2022-04-21 15:47 ` Edgecombe, Rick P
2022-04-21 16:15 ` Linus Torvalds
2022-04-22 0:12 ` Nicholas Piggin
2022-04-22 2:29 ` Edgecombe, Rick P
2022-04-22 2:47 ` Linus Torvalds
2022-04-22 16:54 ` Edgecombe, Rick P
2022-04-22 3:08 ` Nicholas Piggin
2022-04-22 4:31 ` Nicholas Piggin
2022-04-22 17:10 ` Edgecombe, Rick P
2022-04-22 20:22 ` Edgecombe, Rick P
2022-04-22 3:33 ` Nicholas Piggin
2022-04-21 9:47 ` Nicholas Piggin
2022-04-19 21:24 ` Luis Chamberlain
2022-04-19 23:58 ` Edgecombe, Rick P
2022-04-20 7:58 ` Petr Mladek
2022-04-19 18:20 ` Mike Rapoport
2022-04-24 17:43 ` Linus Torvalds
2022-04-25 6:48 ` Song Liu
2022-04-21 3:19 ` Nicholas Piggin
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