Modified: trunk/Source/WebKit/ChangeLog (260358 => 260359)
--- trunk/Source/WebKit/ChangeLog 2020-04-20 09:54:34 UTC (rev 260358)
+++ trunk/Source/WebKit/ChangeLog 2020-04-20 10:22:53 UTC (rev 260359)
@@ -1,3 +1,13 @@
+2020-04-20 Pablo Saavedra <psaave...@igalia.com>
+
+ [GTK][WPE] lowWatermarkPages() in MemoryPressureMonitor.cpp only searches the "low" value inside the first "Node" section
+ https://bugs.webkit.org/show_bug.cgi?id=210345
+
+ Reviewed by Adrian Perez de Castro.
+
+ * UIProcess/linux/MemoryPressureMonitor.cpp:
+ (WebKit::lowWatermarkPages):
+
2020-04-20 Carlos Garcia Campos <cgar...@igalia.com>
[GTK][WPE] Enable resource load statistics
Modified: trunk/Source/WebKit/UIProcess/linux/MemoryPressureMonitor.cpp (260358 => 260359)
--- trunk/Source/WebKit/UIProcess/linux/MemoryPressureMonitor.cpp 2020-04-20 09:54:34 UTC (rev 260358)
+++ trunk/Source/WebKit/UIProcess/linux/MemoryPressureMonitor.cpp 2020-04-20 10:22:53 UTC (rev 260359)
@@ -66,9 +66,48 @@
#define STRINGIFY(val) STRINGIFY_EXPANDED(val)
#define ZONEINFO_TOKEN_BUFFER_SIZE 128
+// The lowWatermark is the sum of the low watermarks across all zones as the
+// MemAvailable info was implemented in /proc/meminfo since version 3.14 of the
+// kernel (added by commit 34e431b0a, source git.kernel.org):
+//
+// MemAvailable: An estimate of how much memory is available for starting new
+// applications, without swapping. Calculated from MemFree,
+// SReclaimable, the size of the file LRU lists, and the low
+// watermarks in each zone.
+// The estimate takes into account that the system needs some
+// page cache to function well, and that not all reclaimable
+// slab will be reclaimable, due to items being in use. The
+// impact of those factors will vary from system to system.
+//
+// The fscanf() reads the input stream file until the argument list passed as
+// parameters is successfully filled.
+//
+// In our immplemetation the `while (!feof(zoneInfoFile))` loop follows the next
+// logic:
+//
+// - the first `fscanf(zoneInfoFile, " Node %*u, zone %...[^\n]\n", buffer);`
+// iterates the `Node` sections.
+// - Then, when we found a Normal node, we start to read each single
+// `fscanf(zoneInfoFile, "%...s", buffer);` until find a `low` token.
+// - We read the next token which is the actual `low` value and we add it to the
+// `sumLow` summation.
+//
+// The second fscanf() reads tokens one by one because the format of each row is
+// not homogeneous (2, 3 or 6 values):
+//
+// Node 0, zone Normal
+// pages free 27303
+// min 20500
+// low 24089
+// high 27678
+// spanned 3414016
+// present 3414016
+// managed 3337293
+// protection: (0, 0, 0, 0, 0)
static size_t lowWatermarkPages(FILE* zoneInfoFile)
{
size_t low = 0;
+ size_t sumLow = 0;
char buffer[ZONEINFO_TOKEN_BUFFER_SIZE + 1];
bool inNormalZone = false;
@@ -83,11 +122,13 @@
r = fscanf(zoneInfoFile, "%" STRINGIFY(ZONEINFO_TOKEN_BUFFER_SIZE) "s", buffer);
if (r == 1 && inNormalZone && !strcmp(buffer, "low")) {
r = fscanf(zoneInfoFile, "%zu", &low);
- if (r == 1)
- break;
+ if (r == 1) {
+ sumLow += low;
+ continue;
+ }
}
}
- return low;
+ return sumLow;
}
static inline size_t systemPageSize()
