From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by mx.groups.io with SMTP id smtpd.web12.2631.1586487863324378924 for ; Thu, 09 Apr 2020 20:04:23 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: intel.com, ip: 134.134.136.24, mailfrom: eric.dong@intel.com) IronPort-SDR: 1I1SSsNDjul61Ow+4qCLkoeoGdK86QrGdpaYZqPnjKipIxADAQRt/fQ7LmJHlscp0u98EBkCyG BMFnPjBULToQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Apr 2020 20:04:19 -0700 IronPort-SDR: 42BQuouYBLS3KQ0vkwAgLHKLMwHk9N6I6f6BHanVQXVUHpnd8UbwatUFRSG8mQtPBb5jgLEQJ/ yxITVKQqdcew== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,364,1580803200"; d="scan'208";a="425753544" Received: from fmsmsx103.amr.corp.intel.com ([10.18.124.201]) by orsmga005.jf.intel.com with ESMTP; 09 Apr 2020 20:04:19 -0700 Received: from fmsmsx156.amr.corp.intel.com (10.18.116.74) by FMSMSX103.amr.corp.intel.com (10.18.124.201) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 9 Apr 2020 20:04:18 -0700 Received: from shsmsx103.ccr.corp.intel.com (10.239.4.69) by fmsmsx156.amr.corp.intel.com (10.18.116.74) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 9 Apr 2020 20:04:18 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.138]) by SHSMSX103.ccr.corp.intel.com ([169.254.4.146]) with mapi id 14.03.0439.000; Fri, 10 Apr 2020 10:59:50 +0800 From: "Dong, Eric" To: Ray Ni , "devel@edk2.groups.io" CC: "Ni, Ray" , "Zeng, Star" Subject: Re: [PATCH v3] UefiCpuPkg/PiSmmCpuDxeSmm: Improve the performance of GetFreeToken() Thread-Topic: [PATCH v3] UefiCpuPkg/PiSmmCpuDxeSmm: Improve the performance of GetFreeToken() Thread-Index: AQHWDuMlY+ABtlkwN02HvU/rYEHvLqhxqjyQ Date: Fri, 10 Apr 2020 02:59:49 +0000 Message-ID: References: <20200410025126.15460-1-niruiyu@users.noreply.github.com> In-Reply-To: <20200410025126.15460-1-niruiyu@users.noreply.github.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] MIME-Version: 1.0 Return-Path: eric.dong@intel.com Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Reviewed-by: Eric Dong > -----Original Message----- > From: Ray Ni [mailto:niruiyu@users.noreply.github.com] > Sent: Friday, April 10, 2020 10:51 AM > To: devel@edk2.groups.io > Cc: Ni, Ray ; Dong, Eric ; Zeng, S= tar > > Subject: [PATCH v3] UefiCpuPkg/PiSmmCpuDxeSmm: Improve the > performance of GetFreeToken() >=20 > Today's GetFreeToken() runs at the algorithm complexity of O(n) where n i= s > the size of the token list. >=20 > The change introduces a new global variable FirstFreeToken and it always > points to the first free token. So the algorithm complexity of GetFreeTok= en() > decreases from O(n) to O(1). >=20 > The improvement matters when some SMI code uses StartupThisAP() > service for each of the AP such that the algorithm complexity becomes O(n= ) > * O(m) where m is the AP count. >=20 > As next steps, > 1. PROCEDURE_TOKEN.Used field can be optimized out because all tokens > before FirstFreeToken should have "Used" set while all after FirstFreeTok= en > should have "Used" cleared. > 2. ResetTokens() can be optimized to only reset tokens before > FirstFreeToken. >=20 > v2: add missing line in InitializeDataForMmMp. > v3: update copyright year to 2020. >=20 > Signed-off-by: Ray Ni > Cc: Eric Dong > Cc: Star Zeng > --- > UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 71 ++++++++-------------- > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h | 3 +- > 2 files changed, 27 insertions(+), 47 deletions(-) >=20 > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > index c285a70ebb..93cac5e4fa 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c > @@ -453,6 +453,11 @@ ResetTokens ( >=20 > Link =3D GetNextNode (&gSmmCpuPrivate->TokenList, Link); > } > + > + // > + // Reset the FirstFreeToken to the beginning of token list upon exitin= g SMI. > + // > + gSmmCpuPrivate->FirstFreeToken =3D GetFirstNode > + (&gSmmCpuPrivate->TokenList); > } >=20 > /** > @@ -1060,23 +1065,21 @@ IsTokenInUse ( > /** > Allocate buffer for the SPIN_LOCK and PROCEDURE_TOKEN. >=20 > + @return First token of the token buffer. > **/ > -VOID > +LIST_ENTRY * > AllocateTokenBuffer ( > VOID > ) > { > UINTN SpinLockSize; > UINT32 TokenCountPerChunk; > - UINTN ProcTokenSize; > UINTN Index; > - PROCEDURE_TOKEN *ProcToken; > SPIN_LOCK *SpinLock; > UINT8 *SpinLockBuffer; > - UINT8 *ProcTokenBuffer; > + PROCEDURE_TOKEN *ProcTokens; >=20 > SpinLockSize =3D GetSpinLockProperties (); > - ProcTokenSize =3D sizeof (PROCEDURE_TOKEN); >=20 > TokenCountPerChunk =3D FixedPcdGet32 > (PcdCpuSmmMpTokenCountPerChunk); > ASSERT (TokenCountPerChunk !=3D 0); > @@ -1092,49 +1095,22 @@ AllocateTokenBuffer ( > SpinLockBuffer =3D AllocatePool (SpinLockSize * TokenCountPerChunk); > ASSERT (SpinLockBuffer !=3D NULL); >=20 > - ProcTokenBuffer =3D AllocatePool (ProcTokenSize * TokenCountPerChunk); > - ASSERT (ProcTokenBuffer !=3D NULL); > + ProcTokens =3D AllocatePool (sizeof (PROCEDURE_TOKEN) * > + TokenCountPerChunk); ASSERT (ProcTokens !=3D NULL); >=20 > for (Index =3D 0; Index < TokenCountPerChunk; Index++) { > SpinLock =3D (SPIN_LOCK *)(SpinLockBuffer + SpinLockSize * Index); > InitializeSpinLock (SpinLock); >=20 > - ProcToken =3D (PROCEDURE_TOKEN *)(ProcTokenBuffer + ProcTokenSize * > Index); > - ProcToken->Signature =3D PROCEDURE_TOKEN_SIGNATURE; > - ProcToken->SpinLock =3D SpinLock; > - ProcToken->Used =3D FALSE; > - ProcToken->RunningApCount =3D 0; > + ProcTokens[Index].Signature =3D PROCEDURE_TOKEN_SIGNATURE; > + ProcTokens[Index].SpinLock =3D SpinLock; > + ProcTokens[Index].Used =3D FALSE; > + ProcTokens[Index].RunningApCount =3D 0; >=20 > - InsertTailList (&gSmmCpuPrivate->TokenList, &ProcToken->Link); > + InsertTailList (&gSmmCpuPrivate->TokenList, > + &ProcTokens[Index].Link); > } > -} >=20 > -/** > - Find first free token in the allocated token list. > - > - @retval return the first free PROCEDURE_TOKEN. > - > -**/ > -PROCEDURE_TOKEN * > -FindFirstFreeToken ( > - VOID > - ) > -{ > - LIST_ENTRY *Link; > - PROCEDURE_TOKEN *ProcToken; > - > - Link =3D GetFirstNode (&gSmmCpuPrivate->TokenList); > - while (!IsNull (&gSmmCpuPrivate->TokenList, Link)) { > - ProcToken =3D PROCEDURE_TOKEN_FROM_LINK (Link); > - > - if (!ProcToken->Used) { > - return ProcToken; > - } > - > - Link =3D GetNextNode (&gSmmCpuPrivate->TokenList, Link); > - } > - > - return NULL; > + return &ProcTokens[0].Link; > } >=20 > /** > @@ -1154,12 +1130,15 @@ GetFreeToken ( > { > PROCEDURE_TOKEN *NewToken; >=20 > - NewToken =3D FindFirstFreeToken (); > - if (NewToken =3D=3D NULL) { > - AllocateTokenBuffer (); > - NewToken =3D FindFirstFreeToken (); > + // > + // If FirstFreeToken meets the end of token list, enlarge the token li= st. > + // Set FirstFreeToken to the first free token. > + // > + if (gSmmCpuPrivate->FirstFreeToken =3D=3D &gSmmCpuPrivate->TokenList) = { > + gSmmCpuPrivate->FirstFreeToken =3D AllocateTokenBuffer (); > } > - ASSERT (NewToken !=3D NULL); > + NewToken =3D PROCEDURE_TOKEN_FROM_LINK > + (gSmmCpuPrivate->FirstFreeToken); gSmmCpuPrivate->FirstFreeToken =3D > + GetNextNode (&gSmmCpuPrivate->TokenList, > + gSmmCpuPrivate->FirstFreeToken); >=20 > NewToken->Used =3D TRUE; > NewToken->RunningApCount =3D RunningApsCount; @@ -1781,7 +1760,7 > @@ InitializeDataForMmMp ( >=20 > InitializeListHead (&gSmmCpuPrivate->TokenList); >=20 > - AllocateTokenBuffer (); > + gSmmCpuPrivate->FirstFreeToken =3D AllocateTokenBuffer (); > } >=20 > /** > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h > index fe7e8b0323..c9b3b739f3 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.h > @@ -1,7 +1,7 @@ > /** @file > Agent Module to load other modules to deploy SMM Entry Vector for X86 > CPU. >=20 > -Copyright (c) 2009 - 2019, Intel Corporation. All rights reserved.
> +Copyright (c) 2009 - 2020, Intel Corporation. All rights reserved.
> Copyright (c) 2017, AMD Incorporated. All rights reserved.
>=20 > SPDX-License-Identifier: BSD-2-Clause-Patent @@ -255,6 +255,7 @@ > typedef struct { >=20 > PROCEDURE_WRAPPER *ApWrapperFunc; > LIST_ENTRY TokenList; > + LIST_ENTRY *FirstFreeToken; > } SMM_CPU_PRIVATE_DATA; >=20 > extern SMM_CPU_PRIVATE_DATA *gSmmCpuPrivate; > -- > 2.21.0.windows.1