From: Gilad Ben-Yossef <gilad@benyossef.com> To: linux-kernel@vger.kernel.org Cc: Gilad Ben-Yossef <gilad@benyossef.com>, Christoph Lameter <cl@linux.com>, Chris Metcalf <cmetcalf@tilera.com>, Frederic Weisbecker <fweisbec@gmail.com>, linux-mm@kvack.org, Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>, Sasha Levin <levinsasha928@gmail.com>, Rik van Riel <riel@redhat.com>, Andi Kleen <andi@firstfloor.org>, Mel Gorman <mel@csn.ul.ie>, Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk>, Avi Kivity <avi@redhat.com>, Michal Nazarewicz <mina86@mina86.com>, Kosaki Motohiro <kosaki.motohiro@gmail.com>, Milton Miller <miltonm@bga.com> Subject: [PATCH v8 0/8] Reduce cross CPU IPI interference Date: Sun, 5 Feb 2012 15:33:20 +0200 [thread overview] Message-ID: <1328448800-15794-1-git-send-email-gilad@benyossef.com> (raw) We have lots of infrastructure in place to partition multi-core systems such that we have a group of CPUs that are dedicated to specific task: cgroups, scheduler and interrupt affinity, and cpuisol= boot parameter. Still, kernel code will at times interrupt all CPUs in the system via IPIs for various needs. These IPIs are useful and cannot be avoided altogether, but in certain cases it is possible to interrupt only specific CPUs that have useful work to do and not the entire system. This patch set, inspired by discussions with Peter Zijlstra and Frederic Weisbecker when testing the nohz task patch set, is a first stab at trying to explore doing this by locating the places where such global IPI calls are being made and turning the global IPI into an IPI for a specific group of CPUs. The purpose of the patch set is to get feedback if this is the right way to go for dealing with this issue and indeed, if the issue is even worth dealing with at all. Based on the feedback from this patch set I plan to offer further patches that address similar issue in other code paths. The patch creates an on_each_cpu_mask and on_each_cpu_cond infrastructure API (the former derived from existing arch specific versions in Tile and Arm) and uses them to turn several global IPI invocation to per CPU group invocations. This 8th iteration adds more verbose comments and coding style fixes based on review remarks by Andrew Morton and others. The patch set also available from the ipi_noise_v8 branch at git://github.com/gby/linux.git Merge notes: during merge, kindly squash the first three patches to avoid bisect failures. The last patch in the series is a review helper only. Please do not merge it. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Christoph Lameter <cl@linux.com> CC: Chris Metcalf <cmetcalf@tilera.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: linux-mm@kvack.org CC: Pekka Enberg <penberg@kernel.org> CC: Matt Mackall <mpm@selenic.com> CC: Sasha Levin <levinsasha928@gmail.com> CC: Rik van Riel <riel@redhat.com> CC: Andi Kleen <andi@firstfloor.org> CC: Mel Gorman <mel@csn.ul.ie> CC: Andrew Morton <akpm@linux-foundation.org> CC: Alexander Viro <viro@zeniv.linux.org.uk> CC: Avi Kivity <avi@redhat.com> CC: Michal Nazarewicz <mina86@mina86.com> CC: Kosaki Motohiro <kosaki.motohiro@gmail.com> CC: Milton Miller <miltonm@bga.com> Gilad Ben-Yossef (8): smp: introduce a generic on_each_cpu_mask function arm: move arm over to generic on_each_cpu_mask tile: move tile to use generic on_each_cpu_mask smp: add func to IPI cpus based on parameter func slub: only IPI CPUs that have per cpu obj to flush fs: only send IPI to invalidate LRU BH when needed mm: only IPI CPUs to drain local pages if they exist mm: add vmstat counters for tracking PCP drains arch/arm/kernel/smp_tlb.c | 20 ++------- arch/tile/include/asm/smp.h | 7 --- arch/tile/kernel/smp.c | 19 --------- fs/buffer.c | 15 ++++++- include/linux/smp.h | 46 +++++++++++++++++++++ include/linux/vm_event_item.h | 1 + kernel/smp.c | 89 +++++++++++++++++++++++++++++++++++++++++ mm/page_alloc.c | 44 +++++++++++++++++++- mm/slub.c | 10 ++++- mm/vmstat.c | 2 + 10 files changed, 208 insertions(+), 45 deletions(-)
WARNING: multiple messages have this Message-ID (diff)
From: Gilad Ben-Yossef <gilad@benyossef.com> To: linux-kernel@vger.kernel.org Cc: Gilad Ben-Yossef <gilad@benyossef.com>, Christoph Lameter <cl@linux.com>, Chris Metcalf <cmetcalf@tilera.com>, Frederic Weisbecker <fweisbec@gmail.com>, linux-mm@kvack.org, Pekka Enberg <penberg@kernel.org>, Matt Mackall <mpm@selenic.com>, Sasha Levin <levinsasha928@gmail.com>, Rik van Riel <riel@redhat.com>, Andi Kleen <andi@firstfloor.org>, Mel Gorman <mel@csn.ul.ie>, Andrew Morton <akpm@linux-foundation.org>, Alexander Viro <viro@zeniv.linux.org.uk>, Avi Kivity <avi@redhat.com>, Michal Nazarewicz <mina86@mina86.com>, Kosaki Motohiro <kosaki.motohiro@gmail.com>, Milton Miller <miltonm@bga.com> Subject: [PATCH v8 0/8] Reduce cross CPU IPI interference Date: Sun, 5 Feb 2012 15:33:20 +0200 [thread overview] Message-ID: <1328448800-15794-1-git-send-email-gilad@benyossef.com> (raw) We have lots of infrastructure in place to partition multi-core systems such that we have a group of CPUs that are dedicated to specific task: cgroups, scheduler and interrupt affinity, and cpuisol= boot parameter. Still, kernel code will at times interrupt all CPUs in the system via IPIs for various needs. These IPIs are useful and cannot be avoided altogether, but in certain cases it is possible to interrupt only specific CPUs that have useful work to do and not the entire system. This patch set, inspired by discussions with Peter Zijlstra and Frederic Weisbecker when testing the nohz task patch set, is a first stab at trying to explore doing this by locating the places where such global IPI calls are being made and turning the global IPI into an IPI for a specific group of CPUs. The purpose of the patch set is to get feedback if this is the right way to go for dealing with this issue and indeed, if the issue is even worth dealing with at all. Based on the feedback from this patch set I plan to offer further patches that address similar issue in other code paths. The patch creates an on_each_cpu_mask and on_each_cpu_cond infrastructure API (the former derived from existing arch specific versions in Tile and Arm) and uses them to turn several global IPI invocation to per CPU group invocations. This 8th iteration adds more verbose comments and coding style fixes based on review remarks by Andrew Morton and others. The patch set also available from the ipi_noise_v8 branch at git://github.com/gby/linux.git Merge notes: during merge, kindly squash the first three patches to avoid bisect failures. The last patch in the series is a review helper only. Please do not merge it. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> CC: Christoph Lameter <cl@linux.com> CC: Chris Metcalf <cmetcalf@tilera.com> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: linux-mm@kvack.org CC: Pekka Enberg <penberg@kernel.org> CC: Matt Mackall <mpm@selenic.com> CC: Sasha Levin <levinsasha928@gmail.com> CC: Rik van Riel <riel@redhat.com> CC: Andi Kleen <andi@firstfloor.org> CC: Mel Gorman <mel@csn.ul.ie> CC: Andrew Morton <akpm@linux-foundation.org> CC: Alexander Viro <viro@zeniv.linux.org.uk> CC: Avi Kivity <avi@redhat.com> CC: Michal Nazarewicz <mina86@mina86.com> CC: Kosaki Motohiro <kosaki.motohiro@gmail.com> CC: Milton Miller <miltonm@bga.com> Gilad Ben-Yossef (8): smp: introduce a generic on_each_cpu_mask function arm: move arm over to generic on_each_cpu_mask tile: move tile to use generic on_each_cpu_mask smp: add func to IPI cpus based on parameter func slub: only IPI CPUs that have per cpu obj to flush fs: only send IPI to invalidate LRU BH when needed mm: only IPI CPUs to drain local pages if they exist mm: add vmstat counters for tracking PCP drains arch/arm/kernel/smp_tlb.c | 20 ++------- arch/tile/include/asm/smp.h | 7 --- arch/tile/kernel/smp.c | 19 --------- fs/buffer.c | 15 ++++++- include/linux/smp.h | 46 +++++++++++++++++++++ include/linux/vm_event_item.h | 1 + kernel/smp.c | 89 +++++++++++++++++++++++++++++++++++++++++ mm/page_alloc.c | 44 +++++++++++++++++++- mm/slub.c | 10 ++++- mm/vmstat.c | 2 + 10 files changed, 208 insertions(+), 45 deletions(-) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next reply other threads:[~2012-02-05 13:34 UTC|newest] Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-02-05 13:33 Gilad Ben-Yossef [this message] 2012-02-05 13:33 ` [PATCH v8 0/8] Reduce cross CPU IPI interference Gilad Ben-Yossef 2012-02-05 13:44 ` [PATCH v8 1/8] smp: introduce a generic on_each_cpu_mask function Gilad Ben-Yossef 2012-02-05 13:44 ` Gilad Ben-Yossef 2012-02-05 15:18 ` Srivatsa S. Bhat 2012-02-05 15:18 ` Srivatsa S. Bhat 2012-02-05 13:48 ` [PATCH v8 2/8] arm: move arm over to generic on_each_cpu_mask Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 3/8] tile: move tile to use " Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 4/8] smp: add func to IPI cpus based on parameter func Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-05 15:36 ` Srivatsa S. Bhat 2012-02-05 15:36 ` Srivatsa S. Bhat 2012-02-05 15:46 ` Gilad Ben-Yossef 2012-02-05 15:46 ` Gilad Ben-Yossef 2012-02-05 16:00 ` Srivatsa S. Bhat 2012-02-05 16:00 ` Srivatsa S. Bhat 2012-02-05 16:03 ` Srivatsa S. Bhat 2012-02-05 16:03 ` Srivatsa S. Bhat 2012-02-08 9:30 ` Michal Nazarewicz 2012-02-08 9:30 ` Michal Nazarewicz 2012-02-09 0:03 ` Andrew Morton 2012-02-09 0:03 ` Andrew Morton 2012-02-09 8:08 ` Gilad Ben-Yossef 2012-02-09 8:08 ` Gilad Ben-Yossef 2012-02-09 8:13 ` Andrew Morton 2012-02-09 8:13 ` Andrew Morton 2012-02-09 9:53 ` Gilad Ben-Yossef 2012-02-09 9:53 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 5/8] slub: only IPI CPUs that have per cpu obj to flush Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 6/8] fs: only send IPI to invalidate LRU BH when needed Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 7/8] mm: only IPI CPUs to drain local pages if they exist Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-08 9:33 ` Michal Nazarewicz 2012-02-08 9:33 ` Michal Nazarewicz 2012-02-09 8:09 ` Gilad Ben-Yossef 2012-02-09 8:09 ` Gilad Ben-Yossef 2012-02-05 13:48 ` [PATCH v8 8/8] mm: add vmstat counters for tracking PCP drains Gilad Ben-Yossef 2012-02-05 13:48 ` Gilad Ben-Yossef 2012-02-08 9:36 ` [PATCH v8 0/8] Reduce cross CPU IPI interference Michal Nazarewicz 2012-02-08 9:36 ` Michal Nazarewicz
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1328448800-15794-1-git-send-email-gilad@benyossef.com \ --to=gilad@benyossef.com \ --cc=akpm@linux-foundation.org \ --cc=andi@firstfloor.org \ --cc=avi@redhat.com \ --cc=cl@linux.com \ --cc=cmetcalf@tilera.com \ --cc=fweisbec@gmail.com \ --cc=kosaki.motohiro@gmail.com \ --cc=levinsasha928@gmail.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=mel@csn.ul.ie \ --cc=miltonm@bga.com \ --cc=mina86@mina86.com \ --cc=mpm@selenic.com \ --cc=penberg@kernel.org \ --cc=riel@redhat.com \ --cc=viro@zeniv.linux.org.uk \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.