Message ID | 1465813577-13780-1-git-send-email-olivier.matz@6wind.com (mailing list archive) |
---|---|
State | Superseded, archived |
Delegated to: | Thomas Monjalon |
Headers |
Return-Path: <dev-bounces@dpdk.org> X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [IPv6:::1]) by dpdk.org (Postfix) with ESMTP id 5EDFF37AF; Mon, 13 Jun 2016 12:27:07 +0200 (CEST) Received: from proxy.6wind.com (host.76.145.23.62.rev.coltfrance.com [62.23.145.76]) by dpdk.org (Postfix) with ESMTP id 5F9472C3F for <dev@dpdk.org>; Mon, 13 Jun 2016 12:27:06 +0200 (CEST) Received: from glumotte.dev.6wind.com (unknown [10.16.0.195]) by proxy.6wind.com (Postfix) with ESMTP id 30D2D25CA0; Mon, 13 Jun 2016 12:27:06 +0200 (CEST) From: Olivier Matz <olivier.matz@6wind.com> To: sergio.gonzalez.monroy@intel.com, david.marchand@6wind.com, pmatilai@redhat.com, thomas.monjalon@6wind.com, dev@dpdk.org Date: Mon, 13 Jun 2016 12:26:17 +0200 Message-Id: <1465813577-13780-1-git-send-email-olivier.matz@6wind.com> X-Mailer: git-send-email 2.8.0.rc3 Subject: [dpdk-dev] [PATCH] mem: skip memory locking on failure X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org> |
Commit Message
Olivier Matz
June 13, 2016, 10:26 a.m. UTC
Since recently [1], it is not possible to run the dpdk with user
(non-root) privileges and the --no-huge option. This is because the eal
layer tries to lock the memory. Using locked memory is mandatory for
physical devices because they reference physical addresses.
But a user may want to start the dpdk without locked memory, because he
does not have the permission to do so, and/or does not have this need.
Moreover, the option --no-huge is still not functional today since the
physical memory address is not properly filled, so the initial patch is
not really useful.
This commit fixes this issue by retrying the mmap() wihout the
MAP_LOCKED flag if the first mmap() failed.
[1] http://www.dpdk.org/ml/archives/dev/2016-May/039404.html
Fixes: 593a084afc2b ("mem: lock pages when not using hugepages")
Reported-by: Panu Matilainen <pmatilai@redhat.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
---
lib/librte_eal/linuxapp/eal/eal_memory.c | 9 +++++++++
1 file changed, 9 insertions(+)
Comments
On 06/13/2016 01:26 PM, Olivier Matz wrote: > Since recently [1], it is not possible to run the dpdk with user > (non-root) privileges and the --no-huge option. This is because the eal > layer tries to lock the memory. Using locked memory is mandatory for > physical devices because they reference physical addresses. > > But a user may want to start the dpdk without locked memory, because he > does not have the permission to do so, and/or does not have this need. > > Moreover, the option --no-huge is still not functional today since the > physical memory address is not properly filled, so the initial patch is > not really useful. > > This commit fixes this issue by retrying the mmap() wihout the > MAP_LOCKED flag if the first mmap() failed. > > [1] http://www.dpdk.org/ml/archives/dev/2016-May/039404.html > > Fixes: 593a084afc2b ("mem: lock pages when not using hugepages") > Reported-by: Panu Matilainen <pmatilai@redhat.com> > Signed-off-by: Olivier Matz <olivier.matz@6wind.com> > --- > lib/librte_eal/linuxapp/eal/eal_memory.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c > index 79d1d2d..08692d1 100644 > --- a/lib/librte_eal/linuxapp/eal/eal_memory.c > +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c > @@ -1075,6 +1075,15 @@ rte_eal_hugepage_init(void) > if (internal_config.no_hugetlbfs) { > addr = mmap(NULL, internal_config.memory, PROT_READ | PROT_WRITE, > MAP_LOCKED | MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); > + /* retry without MAP_LOCKED */ > + if (addr == MAP_FAILED && errno == EAGAIN) { > + addr = mmap(NULL, internal_config.memory, > + PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); > + if (addr != MAP_FAILED) > + RTE_LOG(NOTICE, EAL, > + "Cannot lock memory: don't use physical devices\n"); > + } > if (addr == MAP_FAILED) { > RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__, > strerror(errno)); > I'm not really that familiar with dpdk memory usage, but gut feeling says such a thing needs to be explicit - either you explicitly ask for memory that doesn't need to be locked, or this simply fails with no retries. Or something like that. But "maybe I did, maybe I didn't" doesn't seem like very good API semantics to me :) Are there actual plans to make --no-huge work with real devices? If not then documenting --no-huge to imply unlocked memory is one option I guess. - Panu - - Panu -
Hi Panu, On 06/14/2016 03:21 PM, Panu Matilainen wrote: > On 06/13/2016 01:26 PM, Olivier Matz wrote: >> Since recently [1], it is not possible to run the dpdk with user >> (non-root) privileges and the --no-huge option. This is because the eal >> layer tries to lock the memory. Using locked memory is mandatory for >> physical devices because they reference physical addresses. >> >> But a user may want to start the dpdk without locked memory, because he >> does not have the permission to do so, and/or does not have this need. >> >> Moreover, the option --no-huge is still not functional today since the >> physical memory address is not properly filled, so the initial patch is >> not really useful. >> >> This commit fixes this issue by retrying the mmap() wihout the >> MAP_LOCKED flag if the first mmap() failed. >> >> [1] http://www.dpdk.org/ml/archives/dev/2016-May/039404.html >> >> Fixes: 593a084afc2b ("mem: lock pages when not using hugepages") >> Reported-by: Panu Matilainen <pmatilai@redhat.com> >> Signed-off-by: Olivier Matz <olivier.matz@6wind.com> >> --- >> lib/librte_eal/linuxapp/eal/eal_memory.c | 9 +++++++++ >> 1 file changed, 9 insertions(+) >> >> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c >> b/lib/librte_eal/linuxapp/eal/eal_memory.c >> index 79d1d2d..08692d1 100644 >> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c >> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c >> @@ -1075,6 +1075,15 @@ rte_eal_hugepage_init(void) >> if (internal_config.no_hugetlbfs) { >> addr = mmap(NULL, internal_config.memory, PROT_READ | >> PROT_WRITE, >> MAP_LOCKED | MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); >> + /* retry without MAP_LOCKED */ >> + if (addr == MAP_FAILED && errno == EAGAIN) { >> + addr = mmap(NULL, internal_config.memory, >> + PROT_READ | PROT_WRITE, >> + MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); >> + if (addr != MAP_FAILED) >> + RTE_LOG(NOTICE, EAL, >> + "Cannot lock memory: don't use physical devices\n"); >> + } >> if (addr == MAP_FAILED) { >> RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__, >> strerror(errno)); >> > > I'm not really that familiar with dpdk memory usage, but gut feeling > says such a thing needs to be explicit - either you explicitly ask for > memory that doesn't need to be locked, or this simply fails with no > retries. Or something like that. But "maybe I did, maybe I didn't" > doesn't seem like very good API semantics to me :) Yes, you're right. Anyway as this commit is not useful today, it would be better to revert it. > Are there actual plans to make --no-huge work with real devices? I think this is something that could be part of the memory rework referenced by Thomas: http://dpdk.org/ml/archives/dev/2016-April/037444.html I don't know if it's planified yet. > If not then documenting --no-huge to imply unlocked memory is one > option I guess. There is already some words in the known issues: http://dpdk.org/doc/guides/rel_notes/known_issues.html?highlight=known%20issues#pmd-does-not-work-with-no-huge-eal-command-line-parameter Maybe we could add something somewhere else, but I did not find any doc referencing eal options. Only a guide for testpmd here: http://dpdk.org/doc/guides/testpmd_app_ug/run_app.html#eal-command-line-options John, maybe you have an idea? Thanks Olivier
On 06/14/2016 05:12 PM, Olivier MATZ wrote: > Hi Panu, > > On 06/14/2016 03:21 PM, Panu Matilainen wrote: >> On 06/13/2016 01:26 PM, Olivier Matz wrote: >>> Since recently [1], it is not possible to run the dpdk with user >>> (non-root) privileges and the --no-huge option. This is because the eal >>> layer tries to lock the memory. Using locked memory is mandatory for >>> physical devices because they reference physical addresses. >>> >>> But a user may want to start the dpdk without locked memory, because he >>> does not have the permission to do so, and/or does not have this need. >>> >>> Moreover, the option --no-huge is still not functional today since the >>> physical memory address is not properly filled, so the initial patch is >>> not really useful. >>> >>> This commit fixes this issue by retrying the mmap() wihout the >>> MAP_LOCKED flag if the first mmap() failed. >>> >>> [1] http://www.dpdk.org/ml/archives/dev/2016-May/039404.html >>> >>> Fixes: 593a084afc2b ("mem: lock pages when not using hugepages") >>> Reported-by: Panu Matilainen <pmatilai@redhat.com> >>> Signed-off-by: Olivier Matz <olivier.matz@6wind.com> >>> --- >>> lib/librte_eal/linuxapp/eal/eal_memory.c | 9 +++++++++ >>> 1 file changed, 9 insertions(+) >>> >>> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c >>> b/lib/librte_eal/linuxapp/eal/eal_memory.c >>> index 79d1d2d..08692d1 100644 >>> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c >>> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c >>> @@ -1075,6 +1075,15 @@ rte_eal_hugepage_init(void) >>> if (internal_config.no_hugetlbfs) { >>> addr = mmap(NULL, internal_config.memory, PROT_READ | >>> PROT_WRITE, >>> MAP_LOCKED | MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); >>> + /* retry without MAP_LOCKED */ >>> + if (addr == MAP_FAILED && errno == EAGAIN) { >>> + addr = mmap(NULL, internal_config.memory, >>> + PROT_READ | PROT_WRITE, >>> + MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); >>> + if (addr != MAP_FAILED) >>> + RTE_LOG(NOTICE, EAL, >>> + "Cannot lock memory: don't use physical >>> devices\n"); >>> + } >>> if (addr == MAP_FAILED) { >>> RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__, >>> strerror(errno)); >>> >> >> I'm not really that familiar with dpdk memory usage, but gut feeling >> says such a thing needs to be explicit - either you explicitly ask for >> memory that doesn't need to be locked, or this simply fails with no >> retries. Or something like that. But "maybe I did, maybe I didn't" >> doesn't seem like very good API semantics to me :) > > Yes, you're right. Anyway as this commit is not useful today, > it would be better to revert it. I suppose you mean revert the memlock commit, ie this? commit 593a084afc2b441895aeca78a2c4465e450d0ef5 Author: Olivier Matz <olivier.matz@6wind.com> Date: Wed May 18 13:04:42 2016 +0200 mem: lock pages when not using hugepages Reverting that would help in the sense that then we could make the test-suite runnable by regular users (I've some patches for this), and once that is in place it would sort of force dealing with the issue one way or the other in future work in this area :) > >> Are there actual plans to make --no-huge work with real devices? > > I think this is something that could be part of the memory > rework referenced by Thomas: > http://dpdk.org/ml/archives/dev/2016-April/037444.html > > I don't know if it's planified yet. > > >> If not then documenting --no-huge to imply unlocked memory is one >> option I guess. > > There is already some words in the known issues: > http://dpdk.org/doc/guides/rel_notes/known_issues.html?highlight=known%20issues#pmd-does-not-work-with-no-huge-eal-command-line-parameter Right, so it wouldn't be a regression at least. - Panu - > > Maybe we could add something somewhere else, but I did not find > any doc referencing eal options. Only a guide for testpmd here: > http://dpdk.org/doc/guides/testpmd_app_ug/run_app.html#eal-command-line-options > > > John, maybe you have an idea? > > Thanks > Olivier >
diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c index 79d1d2d..08692d1 100644 --- a/lib/librte_eal/linuxapp/eal/eal_memory.c +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c @@ -1075,6 +1075,15 @@ rte_eal_hugepage_init(void) if (internal_config.no_hugetlbfs) { addr = mmap(NULL, internal_config.memory, PROT_READ | PROT_WRITE, MAP_LOCKED | MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); + /* retry without MAP_LOCKED */ + if (addr == MAP_FAILED && errno == EAGAIN) { + addr = mmap(NULL, internal_config.memory, + PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); + if (addr != MAP_FAILED) + RTE_LOG(NOTICE, EAL, + "Cannot lock memory: don't use physical devices\n"); + } if (addr == MAP_FAILED) { RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__, strerror(errno));