From: Sean Christopherson <[email protected]>
Move the invocation of post-reclaim cond_resched() from the callers of
sgx_reclaim_pages() into the reclaim path itself. sgx_reclaim_pages()
is always called in a loop and is always followed by a call to
cond_resched(). This will hold true for the EPC cgroup as well, which
adds even more calls to sgx_reclaim_pages() and thus cond_resched().
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Kristen Carlson Accardi <[email protected]>
Cc: Sean Christopherson <[email protected]>
---
arch/x86/kernel/cpu/sgx/main.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 515e2a5f25bb..4cdeb915dc86 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -367,6 +367,8 @@ static void sgx_reclaim_pages(void)
sgx_free_epc_page(epc_page);
}
+
+ cond_resched();
}
static bool sgx_should_reclaim(unsigned long watermark)
@@ -410,8 +412,6 @@ static int ksgxd(void *p)
if (sgx_should_reclaim(SGX_NR_HIGH_PAGES))
sgx_reclaim_pages();
-
- cond_resched();
}
return 0;
@@ -578,7 +578,6 @@ struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim)
}
sgx_reclaim_pages();
- cond_resched();
}
if (sgx_should_reclaim(SGX_NR_LOW_PAGES))
--
2.37.3
On Fri, Sep 23, 2022 at 03:35:25PM +0300, Jarkko Sakkinen wrote:
> On Fri, Sep 23, 2022 at 03:32:43PM +0300, Jarkko Sakkinen wrote:
> > On Thu, Sep 22, 2022 at 10:10:38AM -0700, Kristen Carlson Accardi wrote:
> > > From: Sean Christopherson <[email protected]>
> > >
> > > Move the invocation of post-reclaim cond_resched() from the callers of
> > > sgx_reclaim_pages() into the reclaim path itself. sgx_reclaim_pages()
> > > is always called in a loop and is always followed by a call to
> > > cond_resched(). This will hold true for the EPC cgroup as well, which
> > > adds even more calls to sgx_reclaim_pages() and thus cond_resched().
> >
> > This would be in my opinion better:
> >
> > "
> > In order to avoid repetion of cond_sched() in ksgxd() and
> > sgx_alloc_epc_page(), move the call inside sgx_reclaim_pages().
> >
> > This will hold true for the EPC cgroup as well, which adds more
> > call sites sgx_reclaim_pages().
> > "
> >
> > This way it is dead obvious and is better description because
> > it enumerates the consequences (i.e. call sites).
>
> Forgot 3rd call site: sgx_reclaim_direct(), which is used by
> SGX2 ioctls. The call sites of sgx_reclaim_direct() do not
> call cond_resched(). You should address why adding this call
> to those flows is fine.
Ofc adding a parameter to sgx_reclaim_pages() for cond_resched() call is
other option (not emphasising either option).
BR, Jarkko
On Fri, Sep 23, 2022 at 03:32:43PM +0300, Jarkko Sakkinen wrote:
> On Thu, Sep 22, 2022 at 10:10:38AM -0700, Kristen Carlson Accardi wrote:
> > From: Sean Christopherson <[email protected]>
> >
> > Move the invocation of post-reclaim cond_resched() from the callers of
> > sgx_reclaim_pages() into the reclaim path itself. sgx_reclaim_pages()
> > is always called in a loop and is always followed by a call to
> > cond_resched(). This will hold true for the EPC cgroup as well, which
> > adds even more calls to sgx_reclaim_pages() and thus cond_resched().
>
> This would be in my opinion better:
>
> "
> In order to avoid repetion of cond_sched() in ksgxd() and
> sgx_alloc_epc_page(), move the call inside sgx_reclaim_pages().
>
> This will hold true for the EPC cgroup as well, which adds more
> call sites sgx_reclaim_pages().
> "
>
> This way it is dead obvious and is better description because
> it enumerates the consequences (i.e. call sites).
Forgot 3rd call site: sgx_reclaim_direct(), which is used by
SGX2 ioctls. The call sites of sgx_reclaim_direct() do not
call cond_resched(). You should address why adding this call
to those flows is fine.
BR, Jarkko
On Thu, Sep 22, 2022 at 10:10:38AM -0700, Kristen Carlson Accardi wrote:
> From: Sean Christopherson <[email protected]>
>
> Move the invocation of post-reclaim cond_resched() from the callers of
> sgx_reclaim_pages() into the reclaim path itself. sgx_reclaim_pages()
> is always called in a loop and is always followed by a call to
> cond_resched(). This will hold true for the EPC cgroup as well, which
> adds even more calls to sgx_reclaim_pages() and thus cond_resched().
This would be in my opinion better:
"
In order to avoid repetion of cond_sched() in ksgxd() and
sgx_alloc_epc_page(), move the call inside sgx_reclaim_pages().
This will hold true for the EPC cgroup as well, which adds more
call sites sgx_reclaim_pages().
"
This way it is dead obvious and is better description because
it enumerates the consequences (i.e. call sites).
BR, Jarkko