lkml.org 
[lkml]   [2015]   [Oct]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH -next] mm/vmacache: inline vmacache_valid_mm()
On (10/08/15 06:23), Davidlohr Bueso wrote:
> >After moving vmacache_update() and vmacache_valid_mm() to include/linux/vmacache.h
> >(both `static inline')
> >
> >
> >./scripts/bloat-o-meter vmlinux.o.old vmlinux.o
> >add/remove: 0/1 grow/shrink: 1/0 up/down: 22/-54 (-32)
> >function old new delta
> >find_vma 97 119 +22
> >vmacache_update 54 - -54
> >
> >
> >Something like this, perhaps?
>
> iirc we actually had something like this in its original form, and akpm was forced
> to move things around for all users to be happy and not break the build. But yeah,
> that vmacache_update() could certainly be inlined if we can have it so. It's no
> where near as hot a path as the mm validity check (we have a good hit rate), but still
> seems reasonable.

Hello,

Andrew "was forced to move things around", hm, I need to google for it.

Davidlohr, care to send a V2? (this is just a minor improvement to your
patch).

> >
> >---
> >
> >include/linux/vmacache.h | 21 ++++++++++++++++++++-
> >mm/vmacache.c | 20 --------------------
> >2 files changed, 20 insertions(+), 21 deletions(-)
> >
> >diff --git a/include/linux/vmacache.h b/include/linux/vmacache.h
> >index c3fa0fd4..0ec750b 100644
> >--- a/include/linux/vmacache.h
> >+++ b/include/linux/vmacache.h
> >@@ -15,8 +15,27 @@ static inline void vmacache_flush(struct task_struct *tsk)
> > memset(tsk->vmacache, 0, sizeof(tsk->vmacache));
> >}
> >
> >+/*
> >+ * This task may be accessing a foreign mm via (for example)
> >+ * get_user_pages()->find_vma(). The vmacache is task-local and this
> >+ * task's vmacache pertains to a different mm (ie, its own). There is
> >+ * nothing we can do here.
> >+ *
> >+ * Also handle the case where a kernel thread has adopted this mm via use_mm().
> >+ * That kernel thread's vmacache is not applicable to this mm.
> >+ */
> >+static bool vmacache_valid_mm(struct mm_struct *mm)
>
> This needs (explicit) inlined, no?
>

oh, yeah. Funny how I said "both `static inline'" and made 'inline' only
one of them.

-ss


\
 
 \ /
  Last update: 2015-10-08 16:01    [W:0.060 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site