From 2eaf8e846afd71c30f2a6ff6f863a39b1145b8b6 Mon Sep 17 00:00:00 2001 From: kshithijiyer Date: Wed, 5 Jun 2019 19:40:29 +0530 Subject: Fixing formatting errors in markdown files There are a lot of fromatting error is markdown files peresent under /doc directiory of the project. Fixing formatting errors and sending a patch. Fixes: bz#1718273 Change-Id: I08f938088bbaaafddf634f73616ea0dbfe7aedf3 Signed-off-by: kshithijiyer --- doc/developer-guide/datastructure-iobuf.md | 36 +++++++++++++++--------------- 1 file changed, 18 insertions(+), 18 deletions(-) (limited to 'doc/developer-guide/datastructure-iobuf.md') diff --git a/doc/developer-guide/datastructure-iobuf.md b/doc/developer-guide/datastructure-iobuf.md index 5f521f1485f..03604e3672c 100644 --- a/doc/developer-guide/datastructure-iobuf.md +++ b/doc/developer-guide/datastructure-iobuf.md @@ -1,6 +1,6 @@ -#Iobuf-pool -##Datastructures -###iobuf +# Iobuf-pool +## Datastructures +### iobuf Short for IO Buffer. It is one allocatable unit for the consumers of the IOBUF API, each unit hosts @page_size(defined in arena structure) bytes of memory. As initial step of processing a fop, the IO buffer passed onto GlusterFS by the @@ -28,7 +28,7 @@ struct iobuf { }; ``` -###iobref +### iobref There may be need of multiple iobufs for a single fop, like in vectored read/write. Hence multiple iobufs(default 16) are encapsulated under one iobref. ``` @@ -40,7 +40,7 @@ struct iobref { int used; /* number of iobufs added to this iobref */ }; ``` -###iobuf_arenas +### iobuf_arenas One region of memory MMAPed from the operating system. Each region MMAPs @arena_size bytes of memory, and hosts @arena_size / @page_size IOBUFs. The same sized iobufs are grouped into one arena, for sanity of access. @@ -77,7 +77,7 @@ struct iobuf_arena { }; ``` -###iobuf_pool +### iobuf_pool Pool of Iobufs. As there may be many Io buffers required by the filesystem, a pool of iobufs are preallocated and kept, if these preallocated ones are exhausted only then the standard malloc/free is called, thus improving the @@ -139,8 +139,8 @@ arenas in the purge list are destroyed only if there is atleast one arena in (e.g: If there is an arena (page_size=128KB, count=32) in purge list, this arena is destroyed(munmap) only if there is an arena in 'arenas' list with page_size=128KB). -##APIs -###iobuf_get +## APIs +### iobuf_get ``` struct iobuf *iobuf_get (struct iobuf_pool *iobuf_pool); @@ -149,7 +149,7 @@ Creates a new iobuf of the default page size(128KB hard coded as of yet). Also takes a reference(increments ref count), hence no need of doing it explicitly after getting iobuf. -###iobuf_get2 +### iobuf_get2 ``` struct iobuf * iobuf_get2 (struct iobuf_pool *iobuf_pool, size_t page_size); @@ -179,7 +179,7 @@ if (requested iobuf size > Max iobuf size in the pool(1MB as of yet)) Also takes a reference(increments ref count), hence no need of doing it explicitly after getting iobuf. -###iobuf_ref +### iobuf_ref ``` struct iobuf *iobuf_ref (struct iobuf *iobuf); @@ -188,7 +188,7 @@ struct iobuf *iobuf_ref (struct iobuf *iobuf); xlator/function/, its a good practice to take a reference so that iobuf is not deleted by the allocator. -###iobuf_unref +### iobuf_unref ``` void iobuf_unref (struct iobuf *iobuf); ``` @@ -203,33 +203,33 @@ Unreference the iobuf, if the ref count is zero iobuf is considered free. Every iobuf_ref should have a corresponding iobuf_unref, and also every iobuf_get/2 should have a correspondning iobuf_unref. -###iobref_new +### iobref_new ``` struct iobref *iobref_new (); ``` Creates a new iobref structure and returns its pointer. -###iobref_ref +### iobref_ref ``` struct iobref *iobref_ref (struct iobref *iobref); ``` Take a reference on the iobref. -###iobref_unref +### iobref_unref ``` void iobref_unref (struct iobref *iobref); ``` Decrements the reference count of the iobref. If the ref count is 0, then unref all the iobufs(iobuf_unref) in the iobref, and destroy the iobref. -###iobref_add +### iobref_add ``` int iobref_add (struct iobref *iobref, struct iobuf *iobuf); ``` Adds the given iobuf into the iobref, it takes a ref on the iobuf before adding it, hence explicit iobuf_ref is not required if adding to the iobref. -###iobref_merge +### iobref_merge ``` int iobref_merge (struct iobref *to, struct iobref *from); ``` @@ -239,13 +239,13 @@ on all the iobufs added to the 'to' iobref. Hence iobref_unref should be performed both on 'from' and 'to' iobrefs (performing iobref_unref only on 'to' will not free the iobufs and may result in leak). -###iobref_clear +### iobref_clear ``` void iobref_clear (struct iobref *iobref); ``` Unreference all the iobufs in the iobref, and also unref the iobref. -##Iobuf Leaks +## Iobuf Leaks If all iobuf_refs/iobuf_new do not have correspondning iobuf_unref, then the iobufs are not freed and recurring execution of such code path may lead to huge memory leaks. The easiest way to identify if a memory leak is caused by iobufs -- cgit